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Azithromycin is a macrolide antibacterial drug indicated for the treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions listed below. Recommended dosages and durations of therapy in adult and pediatric patient populations vary in these indications [see Dosage and Administration ( 2 )].

Adult Patients ( 2.1 ) Infection Recommended Dose/Duration of Therapy Community-acquired pneumonia (mild severity) Pharyngitis/tonsillitis (second-line therapy) Skin/skin structure (uncomplicated) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5. Acute bacterial exacerbations of chronic bronchitis (mild to moderate) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5 or 500 mg once daily for 3 days. Acute bacterial sinusitis 500 mg once daily for 3 days. Genital ulcer disease (chancroid) Non-gonococcal urethritis and cervicitis One single 1 gram dose. Gonococcal urethritis and cervicitis One single 2 gram dose. Pediatric Patients ( 2.2 ) Infection Recommended Dose/Duration of Therapy Acute otitis media (6 months of age and older) 30 mg/kg as a single dose or 10 mg/kg once daily for 3 days or 10 mg/kg as a single dose on Day 1 followed by 5 mg/kg/day on Days 2 through 5. Acute bacterial sinusitis (6 months of age and older) 10 mg/kg once daily for 3 days. Community-acquired pneumonia (6 months of age and older) 10 mg/kg as a single dose on Day 1 followed by 5 mg/kg once daily on Days 2 through 5. Pharyngitis/tonsillitis (2 years of age and older) 12 mg/kg once daily for 5 days.

Azithromycin tablets, USP, equivalent to 250 mg azithromycin, are white, oval-shaped, unscored, film-coated tablets, debossed GG D6 on one side and plain on the reverse side, and are supplied as follows: Package of 6 unit-of-use blisters NDC 76420-404-06 (relabeled from NDC 0781-8089-26) Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Dispense in a tight container.

Patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug. ( 4.1 ) Patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin. ( 4.2 )

Azithromycin tablets, USP contain the active ingredient azithromycin, a macrolide antibacterial drug, for oral administration. Azithromycin has the chemical name (2 R, 3 S, 4 R, 5 R, 8 R, 10 R, 11 R, 12 S, 13 S, 14 R )‑ 13-[(2,6-dideoxy-3- C -methyl-3- O -methyl-α-L- ribo -hexopyranosyl) oxy]-2-ethyl-3,4,10-trihydroxy-3,5,6,8,10,12,14-heptamethyl-11-[[3,4,6-trideoxy-3-(dimethylamino)-β-D- xylo -hexopyranosyl]oxy] -1‑oxa-6-azacyclopentadecan-15-one. Azithromycin is derived from erythromycin; however, it differs chemically from erythromycin in that a methyl-substituted nitrogen atom is incorporated into the lactone ring. Its molecular formula is C 38 H 72 N 2 O 12 , and its molecular weight is 749. Azithromycin has the following structural formula: Azithromycin, as the dihydrate, is a white crystalline powder with a molecular formula of C 38 H 72 N 2 O 12 •2H 2 O and a molecular weight of 785. Each azithromycin tablet, intended for oral administration, contains azithromycin dihydrate equivalent to either 250 mg of azithromycin. In addition, each tablet contains the following inactive ingredients: colloidal silicon dioxide, lecithin, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol, pregelatinized starch, sodium lauryl sulfate, sodium starch glycolate, talc, titanium dioxide and xanthan gum.

Nelfinavir: Close monitoring for known adverse reactions of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted. ( 7.1 ). Warfarin: Use with azithromycin may increase coagulation times; monitor prothrombin time. ( 7.2 ).

Advise the patient to read the FDA-approved patient labeling (Patient Information). General Patient Counseling Azithromycin tablets can be taken with or without food. Patients should also be cautioned not to take aluminum-and magnesium-containing antacids and azithromycin simultaneously. The patient should be directed to discontinue azithromycin immediately and contact a physician if any signs of an allergic reaction occur. Direct parents or caregivers to contact their physician if vomiting and irritability with feeding occurs in the infant. Patients should be counseled that antibacterial drugs including azithromycin should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When azithromycin is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of the therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by azithromycin or other antibacterial drugs in the future. Diarrhea is a common problem caused by antibacterials which usually ends when the antibacterial is discontinued. Sometimes after starting treatment with antibacterials patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibacterial drug. If this occurs, patients should contact their physician as soon as possible.

[See Clinical Pharmacology ( 12.3 ), Indications and Usage ( 1.2 ), and Dosage and Administration ( 2.2 )]. Safety and effectiveness in the treatment of pediatric patients with acute otitis media, acute bacterial sinusitis and community-acquired pneumonia under 6 months of age have not been established. Use of azithromycin for the treatment of acute bacterial sinusitis and community-acquired pneumonia in pediatric patients (6 months of age or greater) is supported by adequate and well-controlled trials in adults. Pharyngitis/Tonsillitis Safety and effectiveness in the treatment of pediatric patients with pharyngitis/tonsillitis under 2 years of age have not been established.

In multiple-dose clinical trials of oral azithromycin, 9% of patients were at least 65 years of age (458/4949) and 3% of patients (144/4949) were at least 75 years of age. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in response between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. Elderly patients may be more susceptible to development of torsades de pointes arrhythmias than younger patients [see Warnings and Precautions ( 5.4 )] . Azithromycin tablets 250 mg contain 0.32 mg of sodium per tablet. Azithromycin tablets 500 mg contain 0.65 mg of sodium per tablet.

Long-term studies in animals have not been performed to evaluate carcinogenic potential. Azithromycin has shown no mutagenic potential in standard laboratory tests: mouse lymphoma assay, human lymphocyte clastogenic assay, and mouse bone marrow clastogenic assay. In fertility studies conducted in male and female rats, oral administration of azithromycin for 64 to 66 days (males) or 15 days (females) prior to and during cohabitation resulted in decreased pregnancy rate at 20 and 30 mg/kg/day when both males and females were treated with azithromycin. This minimal effect on pregnancy rate (approximately 12% reduction compared to concurrent controls) did not become more pronounced when the dose was increased from 20 to 30 mg/kg/day (approximately 0.4 to 0.6 times the adult daily dose of 500 mg based on body surface area) and it was not observed when only one animal in the mated pair was treated. There were no effects on any other reproductive parameters, and there were no effects on fertility at 10 mg/kg/day. The relevance of these findings to patients being treated with azithromycin at the doses and durations recommended in the prescribing information is uncertain.

The following clinically significant adverse reactions are described elsewhere in labeling: Hypersensitivity [see Warnings and Precautions ( 5.1 )] Hepatotoxicity [see Warnings and Precautions ( 5.2 )] Infantile Hypertrophic Pyloric Stenosis (IHPS) [see Warnings and Precautions ( 5.3 )] QT Prolongation [see Warnings and Precautions ( 5.4 )] Cardiovascular Death [see Warnings and Precautions ( 5.5 )] Clostridioides difficile-Associated Diarrhea (CDAD) [see Warnings and Precautions ( 5.6 )] Exacerbation of Myasthenia Gravis [see Warnings and Precautions ( 5.7 )]

Adverse reactions experienced at higher than recommended doses were similar to those seen at normal doses particularly nausea, diarrhea, and vomiting. In the event of overdosage, general symptomatic and supportive measures are indicated as required.

Phospholipidosis (intracellular phospholipid accumulation) has been observed in some tissues of mice, rats, and dogs given multiple doses of azithromycin. It has been demonstrated in numerous organ systems (e.g., eye, dorsal root ganglia, liver, gallbladder, kidney, spleen, and/or pancreas) in dogs and rats treated with azithromycin at doses which, expressed on the basis of body surface area, are similar to or less than the highest recommended adult human dose. This effect has been shown to be reversible after cessation of azithromycin treatment. Based on the pharmacokinetic data, phospholipidosis has been seen in the rat (50 mg/kg/day dose) at the observed maximal plasma concentration of 1.3 mcg/mL (1.6 times the observed C max of 0.821 mcg/mL at the adult dose of 2 g). Similarly, it has been shown in the dog (10 mg/kg/day dose) at the observed maximal serum concentration of 1 mcg/mL (1.2 times the observed C max of 0.821 mcg/mL at the adult dose of 2 g). Phospholipidosis was also observed in neonatal rats dosed for 18 days at 30 mg/kg/day, which is less than the pediatric dose of 60 mg/kg based on the surface area. It was not observed in neonatal rats treated for 10 days at 40 mg/kg/day with mean maximal serum concentrations of 1.86 mcg/mL, approximately 1.5 times the C max of 1.27 mcg/mL at the pediatric dose. Phospholipidosis has been observed in neonatal dogs (10 mg/kg/day) at maximum mean whole blood concentrations of 3.54 mcg/mL, approximately 3 times the pediatric dose C max . The significance of these findings for animals and for humans is unknown.

Risk Summary Available data from published literature and postmarketing experience over several decades with azithromycin use in pregnant women have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data). Developmental toxicity studies with azithromycin in rats, mice, and rabbits showed no drug-induced fetal malformations at doses up to 4, 2, and 2 times, respectively, an adult human daily dose of 500 mg based on body surface area. Decreased viability and delayed development were observed in the offspring of pregnant rats administered azithromycin from day 6 of pregnancy through weaning at a dose equivalent to 4 times an adult human daily dose of 500 mg based on body surface area (see Data) . The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Human Data Available data from published observational studies, case series, and case reports over several decades do not suggest an increased risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes with azithromycin use in pregnant women. Limitations of these data include the lack of randomization and inability to control for confounders such as underlying maternal disease and maternal use of concomitant medications. Animal Data Azithromycin administered during the period of organogenesis did not cause fetal malformations in rats and mice at oral doses up to 200 mg/kg/day (moderately maternally toxic). Based on body surface area, this dose is approximately 4 (rats) and 2 (mice) times an adult human daily dose of 500 mg. In rabbits administered azithromycin at oral doses of 10, 20, and 40 mg/kg/day during organogenesis, reduced maternal body weight and food consumption were observed in all groups; no evidence of fetotoxicity or teratogenicity was observed at these doses, the highest of which is estimated to be 2 times an adult human daily dose of 500 mg based on body surface area. In a pre-and postnatal development study, azithromycin was administered orally to pregnant rats from day 6 of pregnancy until weaning at doses of 50 or 200 mg/kg/day. Maternal toxicity (reduced food consumption and body weight gain; increased stress at parturition) was observed at the higher dose. Effects in the offspring were noted at 200 mg/kg/day during the postnatal development period (decreased viability, delayed developmental landmarks). These effects were not observed in a pre-and postnatal rat study when up to 200 mg/kg/day of azithromycin was given orally beginning on day 15 of pregnancy until weaning.

Acute bacterial exacerbations of chronic bronchitis due to Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae . Acute bacterial sinusitis due to Haemophilus influenzae, Moraxella catarrhalis or Streptococcus pneumoniae . Community-acquired pneumonia due to Chlamydophila pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, or Streptococcus pneumoniae in patients appropriate for oral therapy. Pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative to first-line therapy in individuals who cannot use first-line therapy. Uncomplicated skin and skin structure infections due to Staphylococcus aureus, Streptococcus pyogenes, or Streptococcus agalactiae . Urethritis and cervicitis due to Chlamydia trachomatis or Neisseria gonorrhoeae . Genital ulcer disease in men due to Haemophilus ducreyi (chancroid). Due to the small number of women included in clinical trials, the efficacy of azithromycin in the treatment of chancroid in women has not been established.

Read this Patient Information leaflet before you start taking azithromycin and each time you get a refill. There may be new information. This information does not take the place of talking to your healthcare provider about your medical condition or your treatment. What is azithromycin? Azithromycin is a macrolide antibiotic prescription medicine used in adults 18 years or older to treat certain infections caused by certain germs called bacteria. These bacterial infections include: acute worsening of chronic bronchitis acute sinus infection community-acquired pneumonia infected throat or tonsils skin infections infections of the urethra or cervix genital ulcers in men Azithromycin is also used in children to treat: ear infections community-acquired pneumonia infected throat or tonsils Azithromycin should not be taken by people who cannot tolerate oral medications because they are very ill or have certain other risk factors including: have cystic fibrosis have hospital acquired infections have known or suspected bacteria in the blood need to be in the hospital are elderly have any medical problems that can lower the ability of the immune system to fight infections Azithromycin is not for viral infections such as the common cold. It is not known if azithromycin is safe and effective for genital ulcers in women. It is not known if azithromycin is safe and effective for children with ear infections, sinus infections, and community-acquired pneumonia under 6 months of age. It is not known if azithromycin is safe and effective for infected throat or tonsils in children under 2 years of age. Who should not take azithromycin? Do not take azithromycin if you: have had a severe allergic reaction to certain antibiotics known as macrolides or ketolides including azithromycin and erythromycin. have a history of cholestatic jaundice or hepatic dysfunction that happened with the use of azithromycin. What should I tell my healthcare provider before taking azithromycin? Before you take azithromycin, tell your healthcare provider if you: have pneumonia have cystic fibrosis have known or suspected bacteremia (bacterial infection in the blood) have liver or kidney problems have an irregular heartbeat, especially a problem called “QT prolongation” have a problem that causes muscle weakness (myasthenia gravis) have any other medical problems are pregnant or plan to become pregnant. It is not known if azithromycin will harm your unborn baby. are breastfeeding or plan to breastfeed. Azithromycin has been reported to pass into breast milk. Talk to your healthcare provider about the best way to feed your baby while you take azithromycin. Contact your healthcare provider immediately if you are giving azithromycin to a young child (less than 6 weeks of age) and he or she vomits or becomes irritable when fed. Tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Azithromycin and other medicines may affect each other causing side effects. Azithromycin may affect the way other medicines work, and other medicines may affect how azithromycin works. Especially tell your healthcare provider if you take: nelfinavir a blood thinner (warfarin) digoxin colchicine phenytoin an antacid that contains aluminum or magnesium Know the medicines you take. Keep a list of your medicines and show it to your healthcare provider and pharmacist when you get a new medicine. How should I take azithromycin? Take azithromycin exactly as your healthcare provider tells you to take it. Azithromycin can be taken with or without food. Do not skip any doses of azithromycin or stop taking it, even if you begin to feel better, until you finish your prescribed treatment unless you have a serious allergic reaction or your healthcare provider tells you to stop taking azithromycin. “See What are the possible side effects of azithromycin?” If you skip doses, or do not complete the total course of azithromycin your treatment may not work as well and your infection may be harder to treat. Taking all of your azithromycin doses will help lower the chance that the bacteria will become resistant to azithromycin. If the bacteria becomes resistant to azithromycin, azithromycin and other antibiotic medicines may not work for you in the future. If you take too much azithromycin, call your healthcare provider or get medical help right away. What are the possible side effects of azithromycin? Azithromycin can cause serious side effects, including: Serious allergic reactions. Allergic reactions can happen in people taking azithromycin, even after only 1 dose. Stop taking azithromycin and get emergency medical help right away if you have any of the following symptoms of a severe allergic reaction:otrouble breathing or swallowingoswelling of the lips, tongue, faceothroat tightness, hoarsenessorapid heartbeatofaintnessoskin rash (hives)onew onset of fever and swollen lymph nodesStop taking azithromycin at the first sign of a skin rash and call your healthcare provider. Skin rash may be a sign of a more serious reaction to azithromycin. Liver damage (hepatotoxicity). Hepatotoxicity can happen in people who take azithromycin. Call your healthcare provider right away if you have unexplained symptoms such as:onausea or vomitingoloss of appetiteostomach painochange in the color of your bowel movementsofeveroweaknessodark colored urineoabdominal pain or tendernessoyellowing of your skin or of the whites of your eyesoitchingounusual tirednessStop taking azithromycin and tell your healthcare provider right away if you have yellowing of your skin or white part of your eyes, or if you have dark urine. These can be signs of a serious reaction to azithromycin (a liver problem).• Serious heart rhythm changes that can be life-threatening, including heart stopping (cardiac arrest), QT prolongation, torsades de pointes, feeling that your heart is pounding or racing (palpitations), chest discomfort, or irregular heartbeat. Tell your healthcare provider right away if you or your child feel a fast or irregular heartbeat, get dizzy or faint. Azithromycin may cause a rare heart problem known as prolongation of the QT interval. This condition can cause an abnormal heartbeat and can be very dangerous. The chances of this happening are higher in people: who are elderlyowith a family history of prolonged QT intervalowith low blood potassiumowho take certain medicines to control heart rhythm (antiarrhythmics) Worsening of myasthenia gravis (a problem that causes muscle weakness). Certain antibiotics like azithromycin may cause worsening of myasthenia gravis symptoms, including muscle weakness and breathing problems. Call your healthcare provider right away if you have any worsening muscle weakness or breathing problems. Diarrhea. Tell your healthcare provider right away if you have watery diarrhea, diarrhea that does not go away, or bloody stools. You may experience cramping and a fever. This could happen after you have finished your azithromycin.The most common side effects of azithromycin include:onauseaostomach painovomiting These are not all the possible side effects of azithromycin. Tell your healthcare provider about any side effect that bothers you or that does not go away. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. How should I store azithromycin? Store azithromycin tablets at 20° to 25°C (68° to 77°F). Safely throw away any medicine that is out of date or no longer needed. Keep azithromycin and all medicines out of the reach of children. General information about the safe and effective use of azithromycin. Medicines are sometimes prescribed for purposes other than those listed in the Patient Information leaflet. Do not use azithromycin for a condition for which it was not prescribed. Do not give azithromycin to other people, even if they have the same symptoms you have. It may harm them. This Patient Information leaflet summarizes the most important information about azithromycin. If you would like more information, talk with your healthcare provider. You can ask your pharmacist or healthcare provider for information about azithromycin that is written for health professionals. What are the ingredients in azithromycin tablets? Active ingredient: azithromycin dihydrate Inactive ingredients: colloidal silicon dioxide, lecithin, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol, pregelatinized starch, sodium lauryl sulfate, sodium starch glycolate, talc, titanium dioxide and xanthan gum. This Patient Information has been approved by the U.S. Food and Drug Administration. For Patient Information sheets, please call 1-800-507-2130. Relabeled by: Enovachem PHARMACEUTICALS Torrance, CA 90501

Azithromycin tablets, USP 250 mg (debossed GG D6 on one side and plain on the reverse side) are supplied as white, oval-shaped, unscored, film-coated tablets.

Azithromycin is a macrolide antibacterial drug [see Microbiology ( 12.4 )] .

Based on animal models of infection, the antibacterial activity of azithromycin appears to correlate with the ratio of area under the concentration-time curve to minimum inhibitory concentration (AUC/MIC) for certain pathogens ( S. pneumoniae and S. aureus ). The principal pharmacokinetic/pharmacodynamic parameter best associated with clinical and microbiological cure has not been elucidated in clinical trials with azithromycin. Cardiac Electrophysiology QT c interval prolongation was studied in a randomized, placebo-controlled parallel trial in 116 healthy subjects who received either chloroquine (1000 mg) alone or in combination with oral azithromycin (500 mg, 1000 mg, and 1500 mg once daily). Co‑administration of azithromycin increased the QT c interval in a dose- and concentration- dependent manner. In comparison to chloroquine alone, the maximum mean (95% upper confidence bound) increases in QT c F were 5 (10) ms, 7 (12) ms and 9 (14) ms with the co-administration of 500 mg, 1000 mg and 1500 mg azithromycin, respectively.

Following oral administration of a single 500 mg dose (two 250 mg tablets) to 36 fasted healthy male volunteers, the mean (SD) pharmacokinetic parameters were AUC 0-72 =4.3 (1.2) mcg•hr/mL; C max =0.5 (0.2) mcg/mL; T max =2.2 (0.9) hours. Two azithromycin 250 mg tablets are bioequivalent to a single 500 mg tablet. In a two-way crossover study, 12 adult healthy volunteers (6 males, 6 females) received 1500 mg of azithromycin administered in single daily doses over either 5 days (two 250 mg tablets on day 1, followed by one 250 mg tablet on days 2 to 5) or 3 days (500 mg per day for days 1 to 3). Due to limited serum samples on day 2 (3-day regimen) and days 2 to 4 (5-day regimen), the serum concentration-time profile of each subject was fit to a 3-compartment model and the AUC 0-∞ for the fitted concentration profile was comparable between the 5-day and 3-day regimens. 3-Day Regimen 5-Day Regimen Pharmacokinetic Parameter [mean (SD)] Day 1 Day 3 Day 1 Day 5 C max (serum, mcg/mL) 0.44 (0.22) 0.54 (0.25) 0.43 (0.20) 0.24 (0.06) Serum AUC 0-∞ (mcg•hr/mL) 17.4 (6.2)* 14.9 (3.1)* Serum T 1/2 71.8 hr 68.9 hr *Total AUC for the entire 3-day and 5-day regimens. Absorption The absolute bioavailability of azithromycin 250 mg capsules is 38%. In a two-way crossover study in which 12 healthy subjects received a single 500 mg dose of azithromycin (two 250 mg tablets) with or without a high fat meal, food was shown to increase C max by 23% but had no effect on AUC. When azithromycin oral suspension was administered with food to 28 adult healthy male subjects, C max increased by 56% and AUC was unchanged. Distribution The serum protein binding of azithromycin is variable in the concentration range approximating human exposure, decreasing from 51% at 0.02 mcg/mL to 7% at 2 mcg/mL. The antibacterial activity of azithromycin is pH related and appears to be reduced with decreasing pH, However, the extensive distribution of drug to tissues may be relevant to clinical activity. Azithromycin has been shown to penetrate into human tissues, including skin, lung, tonsil, and cervix. Extensive tissue distribution was confirmed by examination of additional tissues and fluids (bone, ejaculum, prostate, ovary, uterus, salpinx, stomach, liver, and gallbladder). As there are no data from adequate and well-controlled studies of azithromycin treatment of infections in these additional body sites, the clinical significance of these tissue concentration data is unknown. Following a regimen of 500 mg on the first day and 250 mg daily for 4 days, very low concentrations were noted in cerebrospinal fluid (less than 0.01 mcg/mL) in the presence of noninflamed meninges. Metabolism In vitro and in vivo studies to assess the metabolism of azithromycin have not been performed. Elimination Plasma concentrations of azithromycin following single 500 mg oral and IV doses declined in a polyphasic pattern resulting in a mean apparent plasma clearance of 630 mL/min and terminal elimination half-life of 68 hr. The prolonged terminal half-life is thought to be due to extensive uptake and subsequent release of drug from tissues. Biliary excretion of azithromycin, predominantly as unchanged drug, is a major route of elimination. Over the course of a week, approximately 6% of the administered dose appears as unchanged drug in urine. Specific Populations Patients with Renal Impairment Azithromycin pharmacokinetics was investigated in 42 adults (21 to 85 years of age) with varying degrees of renal impairment. Following the oral administration of a single 1 gram dose of azithromycin (4 x 250 mg capsules), mean C max and AUC 0-120 increased by 5.1% and 4.2%, respectively, in subjects with mild to moderate renal impairment (GFR 10 to 80 mL/min) compared to subjects with normal renal function (GFR > 80 mL/min). The mean C max and AUC 0-120 increased 61% and 35%, respectively, in subjects with severe renal impairment (GFR < 10 mL/min) compared to subjects with normal renal function (GFR > 80 mL/min). Patients with Hepatic Impairment The pharmacokinetics of azithromycin in subjects with hepatic impairment has not been established. Male and Female Patients There are no significant differences in the disposition of azithromycin between male and female subjects. No dosage adjustment is recommended based on gender. Geriatric Patients Pharmacokinetic parameters in older volunteers (65 to 85 years old) were similar to those in young adults (18 to 40 years old) for the 5-day therapeutic regimen. Dosage adjustment does not appear to be necessary for older patients with normal renal and hepatic function receiving treatment with this dosage regimen [see Geriatric Use ( 8.5 )] . Pediatric Patients In two clinical studies, azithromycin for oral suspension was dosed at 10 mg/kg on day 1, followed by 5 mg/kg on days 2 through 5 in two groups of pediatric patients (aged 1 to 5 years and 5 to 15 years, respectively). The mean pharmacokinetic parameters on day 5 were C max =0.216 mcg/mL, T max =1.9 hours, and AUC 0-24 =1.822 mcg•hr/mL for the 1 to 5-year-old group and were C max =0.383 mcg/mL, T max =2.4 hours, and AUC 0-24 =3.109 mcg•hr/mL for the 5 to 15-year-old group. In another study, 33 pediatric patients received doses of 12 mg/kg/day (maximum daily dose 500 mg) for 5 days, of whom 31 patients were evaluated for azithromycin pharmacokinetics following a low fat breakfast. In this study, azithromycin concentrations were determined over a 24 hour period following the last daily dose. Patients weighing above 41.7 kg received the maximum adult daily dose of 500 mg. Seventeen patients (weighing 41.7 kg or less) received a total dose of 60 mg/kg. The following table shows pharmacokinetic data in the subset of pediatric patients who received a total dose of 60 mg/kg. Pharmacokinetic Parameter [mean (SD)] 5-Day Regimen (12 mg/kg for 5 days) N 17 C max (mcg/mL) 0.5 (0.4) T max (hr) 2.2 (0.8) AUC 0-24 (mcg⋅hr/mL) 3.9 (1.9) Single dose pharmacokinetics of azithromycin in pediatric patients given doses of 30 mg/kg have not been studied [see Dosage and Administration ( 2 )] . Drug Interaction Studies Drug interaction studies were performed with azithromycin and other drugs likely to be co-administered. The effects of co‑administration of azithromycin on the pharmacokinetics of other drugs are shown in Table 1 and the effects of other drugs on the pharmacokinetics of azithromycin are shown in Table 2 . Co-administration of azithromycin at therapeutic doses had a modest effect on the pharmacokinetics of the drugs listed in Table 1 . No dosage adjustment of drugs listed in Table 1 is recommended when co-administered with azithromycin. Co-administration of azithromycin with efavirenz or fluconazole had a modest effect on the pharmacokinetics of azithromycin. Nelfinavir significantly increased the C max and AUC of azithromycin. No dosage adjustment of azithromycin is recommended when administered with drugs listed in Table 2 [see Drug Interactions ( 7.3 )] . Table 1. Drug Interactions: Pharmacokinetic Parameters for Co-administered Drugs in the Presence of Azithromycin Co-Administered Drug Dose of Co-Administered Drug Dose of Azithromycin n Ratio (with/without azithromycin) of Co-administered Drug Pharmacokinetic Parameters (90% CI); No Effect=1.00 Mean C max Mean AUC Atorvastatin 10 mg/day for 8 days 500 mg/day orally on days 6-8 12 0.83 (0.63 to 1.08) 1.01 (0.81 to 1.25) Carbamazepine 200 mg/day for 2 days, then 200 mg twice a day for 18 days 500 mg/day orally for days 16-18 7 0.97 (0.88 to 1.06) 0.96 (0.88 to 1.06) Cetirizine 20 mg/day for 11 days 500 mg orally on day 7, then 250 mg/day on days 8-11 14 1.03 (0.93 to 1.14) 1.02 (0.92 to 1.13) Didanosine 200 mg orally twice a day for 21 days 1,200 mg/day orally on days 8-21 6 1.44 (0.85 to 2.43) 1.14 (0.83 to 1.57) Efavirenz 400 mg/day for 7 days 600 mg orally on day 7 14 1.04* 0.95* Fluconazole 200 mg orally single dose 1,200 mg orally single dose 18 1.04 (0.98 to 1.11) 1.01 (0.97 to 1.05) Indinavir 800 mg three times a day for 5 days 1,200 mg orally on day 5 18 0.96 (0.86 to 1.08) 0.90 (0.81 to 1.00) Midazolam 15 mg orally on day 3 500 mg/day orally for 3 days 12 1.27 (0.89 to 1.81) 1.26 (1.01 to 1.56) Nelfinavir 750 mg three times a day for 11 days 1,200 mg orally on day 9 14 0.90 (0.81 to 1.01) 0.85 (0.78 to 0.93) Sildenafil 100 mg on days 1 and 4 500 mg/day orally for 3 days 12 1.16 (0.86 to 1.57) 0.92 (0.75 to 1.12) Theophylline 4 mg/kg IV on days 1, 11, 25 500 mg orally on day 7, 250 mg/day on days 8-11 10 1.19 (1.02 to 1.40) 1.02 (0.86 to 1.22) Theophylline 300 mg orally twice a day for 15 days 500 mg orally on day 6, then 250 mg/day on days 7-10 8 1.09 (0.92 to 1.29) 1.08 (0.89 to 1.31) Triazolam 0.125 mg on day 2 500 mg orally on day 1, then 250 mg/day on day 2 12 1.06* 1.02* Trimethoprim/ Sulfamethoxazole 160 mg/800 mg/day orally for 7 days 1,200 mg orally on day 7 12 0.85 (0.75 to 0.97)/ 0.90 (0.78 to 1.03) 0.87 (0.80 to 0.95)/ 0.96 (0.88 to 1.03) Zidovudine 500 mg/day orally for 21 days 600 mg/day orally for 14 days 5 1.12 (0.42 to 3.02) 0.94 (0.52 to 1.70) Zidovudine 500 mg/day orally for 21 days 1,200 mg/day orally for 14 days 4 1.31 (0.43 to 3.97) 1.30 (0.69 to 2.43) * -90% Confidence interval not reported Table 2. Drug Interactions: Pharmacokinetic Parameters for Azithromycin in the Presence of Co-administered Drugs [see Drug Interactions ( 7 )] . Co-Administered Drug Dose of Co-Administered Drug Dose of Azithromycin n Ratio (with/without Co-adminis- tered Drug) of Azithromycin Pharmacokinetic Parameters (90% CI); No Effect=1.00 Mean C max Mean AUC Efavirenz 400 mg/day for 7 days 600 mg orally on day 7 14 1.22 (1.04 to 1.42) 0.92* Fluconazole 200 mg orally single dose 1,200 mg orally single dose 18 0.82 (0.66 to 1.02) 1.07 (0.94 to 1.22) Nelfinavir 750 mg three times a day for 11 days 1,200 mg orally on day 9 14 2.36 (1.77 to 3.15) 2.12 (1.80 to 2.50) * -90% Confidence interval not reported

Warnings and Precautions, Cardiovascular Death ( 5.5 ) 11/2021

Pediatric Use: Safety and effectiveness in the treatment of patients under 6 months of age have not been established. ( 8.4 ) Geriatric Use: Elderly patients may be more susceptible to development of torsades de pointes arrhythmias. ( 8.5 )

Serious (including fatal) allergic and skin reactions: Discontinue azithromycin if reaction occurs. ( 5.1 ) Hepatotoxicity: Severe, and sometimes fatal, hepatotoxicity has been reported. Discontinue azithromycin immediately if signs and symptoms of hepatitis occur. ( 5.2 ) Infantile Hypertrophic Pyloric Stenosis (IHPS): Following the use of azithromycin in neonates (treatment up to 42 days of life), IHPS has been reported. Direct parents and caregivers to contact their physician if vomiting or irritability with feeding occurs. ( 5.3 ) Prolongation of QT interval and cases of torsades de pointes have been reported. This risk which can be fatal should be considered in patients with certain cardiovascular disorders including known QT prolongation or history torsades de pointes , those with proarrhythmic conditions, and with other drugs that prolong the QT interval. ( 5.4 ) Cardiovascular Death: Some observational studies have shown an approximately two-fold increased short-term potential risk of acute cardiovascular death in adults exposed to azithromycin relative to other antibacterial drugs, including amoxicillin. Consider balancing this potential risk with treatment benefits when prescribing azithromycin. ( 5.5 ) Clostridioides difficile -Associated Diarrhea: Evaluate patients if diarrhea occurs. ( 5.6 ) Azithromycin may exacerbate muscle weakness in persons with myasthenia gravis. ( 5.7 )

LABEL

Risk Summary Azithromycin is present in human milk (see Data) . Non-serious adverse reactions have been reported in breastfed infants after maternal administration of azithromycin (see Clinical Considerations ) . There are no available data on the effects of azithromycin on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for azithromycin and any potential adverse effects on the breastfed infant from azithromycin or from the underlying maternal condition. Clinical Considerations Advise women to monitor the breastfed infant for diarrhea, vomiting, or rash. Data Azithromycin breastmilk concentrations were measured in 20 women after receiving a single 2 g oral dose of azithromycin during labor. Breastmilk samples collected on days 3 and 6 postpartum as well as 2 and 4 weeks postpartum revealed the presence of azithromycin in breastmilk up to 4 weeks after dosing. In another study, a single dose of azithromycin 500 mg was administered intravenously to 8 women prior to incision for cesarean section. Breastmilk (colostrum) samples obtained between 12 and 48 hours after dosing revealed that azithromycin persisted in breastmilk up to 48 hours.

Azithromycin is a macrolide antibacterial drug indicated for the treatment of patients with mild to moderate infections caused by susceptible strains of the designated microorganisms in the specific conditions listed below. Recommended dosages and durations of therapy in adult and pediatric patient populations vary in these indications [see Dosage and Administration ( 2 )].

Adult Patients ( 2.1 ) Infection Recommended Dose/Duration of Therapy Community-acquired pneumonia (mild severity) Pharyngitis/tonsillitis (second-line therapy) Skin/skin structure (uncomplicated) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5. Acute bacterial exacerbations of chronic bronchitis (mild to moderate) 500 mg as a single dose on Day 1, followed by 250 mg once daily on Days 2 through 5 or 500 mg once daily for 3 days. Acute bacterial sinusitis 500 mg once daily for 3 days. Genital ulcer disease (chancroid) Non-gonococcal urethritis and cervicitis One single 1 gram dose. Gonococcal urethritis and cervicitis One single 2 gram dose. Pediatric Patients ( 2.2 ) Infection Recommended Dose/Duration of Therapy Acute otitis media (6 months of age and older) 30 mg/kg as a single dose or 10 mg/kg once daily for 3 days or 10 mg/kg as a single dose on Day 1 followed by 5 mg/kg/day on Days 2 through 5. Acute bacterial sinusitis (6 months of age and older) 10 mg/kg once daily for 3 days. Community-acquired pneumonia (6 months of age and older) 10 mg/kg as a single dose on Day 1 followed by 5 mg/kg once daily on Days 2 through 5. Pharyngitis/tonsillitis (2 years of age and older) 12 mg/kg once daily for 5 days.

Azithromycin tablets, USP, equivalent to 250 mg azithromycin, are white, oval-shaped, unscored, film-coated tablets, debossed GG D6 on one side and plain on the reverse side, and are supplied as follows: Package of 6 unit-of-use blisters NDC 76420-404-06 (relabeled from NDC 0781-8089-26) Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Dispense in a tight container.

Patients with known hypersensitivity to azithromycin, erythromycin, any macrolide or ketolide drug. ( 4.1 ) Patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of azithromycin. ( 4.2 )

Nelfinavir: Close monitoring for known adverse reactions of azithromycin, such as liver enzyme abnormalities and hearing impairment, is warranted. ( 7.1 ). Warfarin: Use with azithromycin may increase coagulation times; monitor prothrombin time. ( 7.2 ).

Advise the patient to read the FDA-approved patient labeling (Patient Information). General Patient Counseling Azithromycin tablets can be taken with or without food. Patients should also be cautioned not to take aluminum-and magnesium-containing antacids and azithromycin simultaneously. The patient should be directed to discontinue azithromycin immediately and contact a physician if any signs of an allergic reaction occur. Direct parents or caregivers to contact their physician if vomiting and irritability with feeding occurs in the infant. Patients should be counseled that antibacterial drugs including azithromycin should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When azithromycin is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of the therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by azithromycin or other antibacterial drugs in the future. Diarrhea is a common problem caused by antibacterials which usually ends when the antibacterial is discontinued. Sometimes after starting treatment with antibacterials patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibacterial drug. If this occurs, patients should contact their physician as soon as possible.

[See Clinical Pharmacology ( 12.3 ), Indications and Usage ( 1.2 ), and Dosage and Administration ( 2.2 )]. Safety and effectiveness in the treatment of pediatric patients with acute otitis media, acute bacterial sinusitis and community-acquired pneumonia under 6 months of age have not been established. Use of azithromycin for the treatment of acute bacterial sinusitis and community-acquired pneumonia in pediatric patients (6 months of age or greater) is supported by adequate and well-controlled trials in adults. Pharyngitis/Tonsillitis Safety and effectiveness in the treatment of pediatric patients with pharyngitis/tonsillitis under 2 years of age have not been established.

In multiple-dose clinical trials of oral azithromycin, 9% of patients were at least 65 years of age (458/4949) and 3% of patients (144/4949) were at least 75 years of age. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in response between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. Elderly patients may be more susceptible to development of torsades de pointes arrhythmias than younger patients [see Warnings and Precautions ( 5.4 )] . Azithromycin tablets 250 mg contain 0.32 mg of sodium per tablet. Azithromycin tablets 500 mg contain 0.65 mg of sodium per tablet.

Long-term studies in animals have not been performed to evaluate carcinogenic potential. Azithromycin has shown no mutagenic potential in standard laboratory tests: mouse lymphoma assay, human lymphocyte clastogenic assay, and mouse bone marrow clastogenic assay. In fertility studies conducted in male and female rats, oral administration of azithromycin for 64 to 66 days (males) or 15 days (females) prior to and during cohabitation resulted in decreased pregnancy rate at 20 and 30 mg/kg/day when both males and females were treated with azithromycin. This minimal effect on pregnancy rate (approximately 12% reduction compared to concurrent controls) did not become more pronounced when the dose was increased from 20 to 30 mg/kg/day (approximately 0.4 to 0.6 times the adult daily dose of 500 mg based on body surface area) and it was not observed when only one animal in the mated pair was treated. There were no effects on any other reproductive parameters, and there were no effects on fertility at 10 mg/kg/day. The relevance of these findings to patients being treated with azithromycin at the doses and durations recommended in the prescribing information is uncertain.

The following clinically significant adverse reactions are described elsewhere in labeling: Hypersensitivity [see Warnings and Precautions ( 5.1 )] Hepatotoxicity [see Warnings and Precautions ( 5.2 )] Infantile Hypertrophic Pyloric Stenosis (IHPS) [see Warnings and Precautions ( 5.3 )] QT Prolongation [see Warnings and Precautions ( 5.4 )] Cardiovascular Death [see Warnings and Precautions ( 5.5 )] Clostridioides difficile-Associated Diarrhea (CDAD) [see Warnings and Precautions ( 5.6 )] Exacerbation of Myasthenia Gravis [see Warnings and Precautions ( 5.7 )]

Adverse reactions experienced at higher than recommended doses were similar to those seen at normal doses particularly nausea, diarrhea, and vomiting. In the event of overdosage, general symptomatic and supportive measures are indicated as required.

Azithromycin tablets, USP contain the active ingredient azithromycin, a macrolide antibacterial drug, for oral administration. Azithromycin has the chemical name (2 R, 3 S, 4 R, 5 R, 8 R, 10 R, 11 R, 12 S, 13 S, 14 R )‑ 13-[(2,6-dideoxy-3- C -methyl-3- O -methyl-α-L- ribo -hexopyranosyl) oxy]-2-ethyl-3,4,10-trihydroxy-3,5,6,8,10,12,14-heptamethyl-11-[[3,4,6-trideoxy-3-(dimethylamino)-β-D- xylo -hexopyranosyl]oxy] -1‑oxa-6-azacyclopentadecan-15-one. Azithromycin is derived from erythromycin; however, it differs chemically from erythromycin in that a methyl-substituted nitrogen atom is incorporated into the lactone ring. Its molecular formula is C 38 H 72 N 2 O 12 , and its molecular weight is 749. Azithromycin has the following structural formula: Azithromycin, as the dihydrate, is a white crystalline powder with a molecular formula of C 38 H 72 N 2 O 12 •2H 2 O and a molecular weight of 785. Each azithromycin tablet, intended for oral administration, contains azithromycin dihydrate equivalent to either 250 mg of azithromycin. In addition, each tablet contains the following inactive ingredients: colloidal silicon dioxide, lecithin, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol, pregelatinized starch, sodium lauryl sulfate, sodium starch glycolate, talc, titanium dioxide and xanthan gum.

Phospholipidosis (intracellular phospholipid accumulation) has been observed in some tissues of mice, rats, and dogs given multiple doses of azithromycin. It has been demonstrated in numerous organ systems (e.g., eye, dorsal root ganglia, liver, gallbladder, kidney, spleen, and/or pancreas) in dogs and rats treated with azithromycin at doses which, expressed on the basis of body surface area, are similar to or less than the highest recommended adult human dose. This effect has been shown to be reversible after cessation of azithromycin treatment. Based on the pharmacokinetic data, phospholipidosis has been seen in the rat (50 mg/kg/day dose) at the observed maximal plasma concentration of 1.3 mcg/mL (1.6 times the observed C max of 0.821 mcg/mL at the adult dose of 2 g). Similarly, it has been shown in the dog (10 mg/kg/day dose) at the observed maximal serum concentration of 1 mcg/mL (1.2 times the observed C max of 0.821 mcg/mL at the adult dose of 2 g). Phospholipidosis was also observed in neonatal rats dosed for 18 days at 30 mg/kg/day, which is less than the pediatric dose of 60 mg/kg based on the surface area. It was not observed in neonatal rats treated for 10 days at 40 mg/kg/day with mean maximal serum concentrations of 1.86 mcg/mL, approximately 1.5 times the C max of 1.27 mcg/mL at the pediatric dose. Phospholipidosis has been observed in neonatal dogs (10 mg/kg/day) at maximum mean whole blood concentrations of 3.54 mcg/mL, approximately 3 times the pediatric dose C max . The significance of these findings for animals and for humans is unknown.

Risk Summary Available data from published literature and postmarketing experience over several decades with azithromycin use in pregnant women have not identified any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data). Developmental toxicity studies with azithromycin in rats, mice, and rabbits showed no drug-induced fetal malformations at doses up to 4, 2, and 2 times, respectively, an adult human daily dose of 500 mg based on body surface area. Decreased viability and delayed development were observed in the offspring of pregnant rats administered azithromycin from day 6 of pregnancy through weaning at a dose equivalent to 4 times an adult human daily dose of 500 mg based on body surface area (see Data) . The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Human Data Available data from published observational studies, case series, and case reports over several decades do not suggest an increased risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes with azithromycin use in pregnant women. Limitations of these data include the lack of randomization and inability to control for confounders such as underlying maternal disease and maternal use of concomitant medications. Animal Data Azithromycin administered during the period of organogenesis did not cause fetal malformations in rats and mice at oral doses up to 200 mg/kg/day (moderately maternally toxic). Based on body surface area, this dose is approximately 4 (rats) and 2 (mice) times an adult human daily dose of 500 mg. In rabbits administered azithromycin at oral doses of 10, 20, and 40 mg/kg/day during organogenesis, reduced maternal body weight and food consumption were observed in all groups; no evidence of fetotoxicity or teratogenicity was observed at these doses, the highest of which is estimated to be 2 times an adult human daily dose of 500 mg based on body surface area. In a pre-and postnatal development study, azithromycin was administered orally to pregnant rats from day 6 of pregnancy until weaning at doses of 50 or 200 mg/kg/day. Maternal toxicity (reduced food consumption and body weight gain; increased stress at parturition) was observed at the higher dose. Effects in the offspring were noted at 200 mg/kg/day during the postnatal development period (decreased viability, delayed developmental landmarks). These effects were not observed in a pre-and postnatal rat study when up to 200 mg/kg/day of azithromycin was given orally beginning on day 15 of pregnancy until weaning.

Acute bacterial exacerbations of chronic bronchitis due to Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae . Acute bacterial sinusitis due to Haemophilus influenzae, Moraxella catarrhalis or Streptococcus pneumoniae . Community-acquired pneumonia due to Chlamydophila pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, or Streptococcus pneumoniae in patients appropriate for oral therapy. Pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative to first-line therapy in individuals who cannot use first-line therapy. Uncomplicated skin and skin structure infections due to Staphylococcus aureus, Streptococcus pyogenes, or Streptococcus agalactiae . Urethritis and cervicitis due to Chlamydia trachomatis or Neisseria gonorrhoeae . Genital ulcer disease in men due to Haemophilus ducreyi (chancroid). Due to the small number of women included in clinical trials, the efficacy of azithromycin in the treatment of chancroid in women has not been established.

Read this Patient Information leaflet before you start taking azithromycin and each time you get a refill. There may be new information. This information does not take the place of talking to your healthcare provider about your medical condition or your treatment. What is azithromycin? Azithromycin is a macrolide antibiotic prescription medicine used in adults 18 years or older to treat certain infections caused by certain germs called bacteria. These bacterial infections include: acute worsening of chronic bronchitis acute sinus infection community-acquired pneumonia infected throat or tonsils skin infections infections of the urethra or cervix genital ulcers in men Azithromycin is also used in children to treat: ear infections community-acquired pneumonia infected throat or tonsils Azithromycin should not be taken by people who cannot tolerate oral medications because they are very ill or have certain other risk factors including: have cystic fibrosis have hospital acquired infections have known or suspected bacteria in the blood need to be in the hospital are elderly have any medical problems that can lower the ability of the immune system to fight infections Azithromycin is not for viral infections such as the common cold. It is not known if azithromycin is safe and effective for genital ulcers in women. It is not known if azithromycin is safe and effective for children with ear infections, sinus infections, and community-acquired pneumonia under 6 months of age. It is not known if azithromycin is safe and effective for infected throat or tonsils in children under 2 years of age. Who should not take azithromycin? Do not take azithromycin if you: have had a severe allergic reaction to certain antibiotics known as macrolides or ketolides including azithromycin and erythromycin. have a history of cholestatic jaundice or hepatic dysfunction that happened with the use of azithromycin. What should I tell my healthcare provider before taking azithromycin? Before you take azithromycin, tell your healthcare provider if you: have pneumonia have cystic fibrosis have known or suspected bacteremia (bacterial infection in the blood) have liver or kidney problems have an irregular heartbeat, especially a problem called “QT prolongation” have a problem that causes muscle weakness (myasthenia gravis) have any other medical problems are pregnant or plan to become pregnant. It is not known if azithromycin will harm your unborn baby. are breastfeeding or plan to breastfeed. Azithromycin has been reported to pass into breast milk. Talk to your healthcare provider about the best way to feed your baby while you take azithromycin. Contact your healthcare provider immediately if you are giving azithromycin to a young child (less than 6 weeks of age) and he or she vomits or becomes irritable when fed. Tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Azithromycin and other medicines may affect each other causing side effects. Azithromycin may affect the way other medicines work, and other medicines may affect how azithromycin works. Especially tell your healthcare provider if you take: nelfinavir a blood thinner (warfarin) digoxin colchicine phenytoin an antacid that contains aluminum or magnesium Know the medicines you take. Keep a list of your medicines and show it to your healthcare provider and pharmacist when you get a new medicine. How should I take azithromycin? Take azithromycin exactly as your healthcare provider tells you to take it. Azithromycin can be taken with or without food. Do not skip any doses of azithromycin or stop taking it, even if you begin to feel better, until you finish your prescribed treatment unless you have a serious allergic reaction or your healthcare provider tells you to stop taking azithromycin. “See What are the possible side effects of azithromycin?” If you skip doses, or do not complete the total course of azithromycin your treatment may not work as well and your infection may be harder to treat. Taking all of your azithromycin doses will help lower the chance that the bacteria will become resistant to azithromycin. If the bacteria becomes resistant to azithromycin, azithromycin and other antibiotic medicines may not work for you in the future. If you take too much azithromycin, call your healthcare provider or get medical help right away. What are the possible side effects of azithromycin? Azithromycin can cause serious side effects, including: Serious allergic reactions. Allergic reactions can happen in people taking azithromycin, even after only 1 dose. Stop taking azithromycin and get emergency medical help right away if you have any of the following symptoms of a severe allergic reaction:otrouble breathing or swallowingoswelling of the lips, tongue, faceothroat tightness, hoarsenessorapid heartbeatofaintnessoskin rash (hives)onew onset of fever and swollen lymph nodesStop taking azithromycin at the first sign of a skin rash and call your healthcare provider. Skin rash may be a sign of a more serious reaction to azithromycin. Liver damage (hepatotoxicity). Hepatotoxicity can happen in people who take azithromycin. Call your healthcare provider right away if you have unexplained symptoms such as:onausea or vomitingoloss of appetiteostomach painochange in the color of your bowel movementsofeveroweaknessodark colored urineoabdominal pain or tendernessoyellowing of your skin or of the whites of your eyesoitchingounusual tirednessStop taking azithromycin and tell your healthcare provider right away if you have yellowing of your skin or white part of your eyes, or if you have dark urine. These can be signs of a serious reaction to azithromycin (a liver problem).• Serious heart rhythm changes that can be life-threatening, including heart stopping (cardiac arrest), QT prolongation, torsades de pointes, feeling that your heart is pounding or racing (palpitations), chest discomfort, or irregular heartbeat. Tell your healthcare provider right away if you or your child feel a fast or irregular heartbeat, get dizzy or faint. Azithromycin may cause a rare heart problem known as prolongation of the QT interval. This condition can cause an abnormal heartbeat and can be very dangerous. The chances of this happening are higher in people: who are elderlyowith a family history of prolonged QT intervalowith low blood potassiumowho take certain medicines to control heart rhythm (antiarrhythmics) Worsening of myasthenia gravis (a problem that causes muscle weakness). Certain antibiotics like azithromycin may cause worsening of myasthenia gravis symptoms, including muscle weakness and breathing problems. Call your healthcare provider right away if you have any worsening muscle weakness or breathing problems. Diarrhea. Tell your healthcare provider right away if you have watery diarrhea, diarrhea that does not go away, or bloody stools. You may experience cramping and a fever. This could happen after you have finished your azithromycin.The most common side effects of azithromycin include:onauseaostomach painovomiting These are not all the possible side effects of azithromycin. Tell your healthcare provider about any side effect that bothers you or that does not go away. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. How should I store azithromycin? Store azithromycin tablets at 20° to 25°C (68° to 77°F). Safely throw away any medicine that is out of date or no longer needed. Keep azithromycin and all medicines out of the reach of children. General information about the safe and effective use of azithromycin. Medicines are sometimes prescribed for purposes other than those listed in the Patient Information leaflet. Do not use azithromycin for a condition for which it was not prescribed. Do not give azithromycin to other people, even if they have the same symptoms you have. It may harm them. This Patient Information leaflet summarizes the most important information about azithromycin. If you would like more information, talk with your healthcare provider. You can ask your pharmacist or healthcare provider for information about azithromycin that is written for health professionals. What are the ingredients in azithromycin tablets? Active ingredient: azithromycin dihydrate Inactive ingredients: colloidal silicon dioxide, lecithin, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol, pregelatinized starch, sodium lauryl sulfate, sodium starch glycolate, talc, titanium dioxide and xanthan gum. This Patient Information has been approved by the U.S. Food and Drug Administration. For Patient Information sheets, please call 1-800-507-2130. Relabeled by: Enovachem PHARMACEUTICALS Torrance, CA 90501

Azithromycin tablets, USP 250 mg (debossed GG D6 on one side and plain on the reverse side) are supplied as white, oval-shaped, unscored, film-coated tablets.

Azithromycin is a macrolide antibacterial drug [see Microbiology ( 12.4 )] .

Based on animal models of infection, the antibacterial activity of azithromycin appears to correlate with the ratio of area under the concentration-time curve to minimum inhibitory concentration (AUC/MIC) for certain pathogens ( S. pneumoniae and S. aureus ). The principal pharmacokinetic/pharmacodynamic parameter best associated with clinical and microbiological cure has not been elucidated in clinical trials with azithromycin. Cardiac Electrophysiology QT c interval prolongation was studied in a randomized, placebo-controlled parallel trial in 116 healthy subjects who received either chloroquine (1000 mg) alone or in combination with oral azithromycin (500 mg, 1000 mg, and 1500 mg once daily). Co‑administration of azithromycin increased the QT c interval in a dose- and concentration- dependent manner. In comparison to chloroquine alone, the maximum mean (95% upper confidence bound) increases in QT c F were 5 (10) ms, 7 (12) ms and 9 (14) ms with the co-administration of 500 mg, 1000 mg and 1500 mg azithromycin, respectively.

Following oral administration of a single 500 mg dose (two 250 mg tablets) to 36 fasted healthy male volunteers, the mean (SD) pharmacokinetic parameters were AUC 0-72 =4.3 (1.2) mcg•hr/mL; C max =0.5 (0.2) mcg/mL; T max =2.2 (0.9) hours. Two azithromycin 250 mg tablets are bioequivalent to a single 500 mg tablet. In a two-way crossover study, 12 adult healthy volunteers (6 males, 6 females) received 1500 mg of azithromycin administered in single daily doses over either 5 days (two 250 mg tablets on day 1, followed by one 250 mg tablet on days 2 to 5) or 3 days (500 mg per day for days 1 to 3). Due to limited serum samples on day 2 (3-day regimen) and days 2 to 4 (5-day regimen), the serum concentration-time profile of each subject was fit to a 3-compartment model and the AUC 0-∞ for the fitted concentration profile was comparable between the 5-day and 3-day regimens. 3-Day Regimen 5-Day Regimen Pharmacokinetic Parameter [mean (SD)] Day 1 Day 3 Day 1 Day 5 C max (serum, mcg/mL) 0.44 (0.22) 0.54 (0.25) 0.43 (0.20) 0.24 (0.06) Serum AUC 0-∞ (mcg•hr/mL) 17.4 (6.2)* 14.9 (3.1)* Serum T 1/2 71.8 hr 68.9 hr *Total AUC for the entire 3-day and 5-day regimens. Absorption The absolute bioavailability of azithromycin 250 mg capsules is 38%. In a two-way crossover study in which 12 healthy subjects received a single 500 mg dose of azithromycin (two 250 mg tablets) with or without a high fat meal, food was shown to increase C max by 23% but had no effect on AUC. When azithromycin oral suspension was administered with food to 28 adult healthy male subjects, C max increased by 56% and AUC was unchanged. Distribution The serum protein binding of azithromycin is variable in the concentration range approximating human exposure, decreasing from 51% at 0.02 mcg/mL to 7% at 2 mcg/mL. The antibacterial activity of azithromycin is pH related and appears to be reduced with decreasing pH, However, the extensive distribution of drug to tissues may be relevant to clinical activity. Azithromycin has been shown to penetrate into human tissues, including skin, lung, tonsil, and cervix. Extensive tissue distribution was confirmed by examination of additional tissues and fluids (bone, ejaculum, prostate, ovary, uterus, salpinx, stomach, liver, and gallbladder). As there are no data from adequate and well-controlled studies of azithromycin treatment of infections in these additional body sites, the clinical significance of these tissue concentration data is unknown. Following a regimen of 500 mg on the first day and 250 mg daily for 4 days, very low concentrations were noted in cerebrospinal fluid (less than 0.01 mcg/mL) in the presence of noninflamed meninges. Metabolism In vitro and in vivo studies to assess the metabolism of azithromycin have not been performed. Elimination Plasma concentrations of azithromycin following single 500 mg oral and IV doses declined in a polyphasic pattern resulting in a mean apparent plasma clearance of 630 mL/min and terminal elimination half-life of 68 hr. The prolonged terminal half-life is thought to be due to extensive uptake and subsequent release of drug from tissues. Biliary excretion of azithromycin, predominantly as unchanged drug, is a major route of elimination. Over the course of a week, approximately 6% of the administered dose appears as unchanged drug in urine. Specific Populations Patients with Renal Impairment Azithromycin pharmacokinetics was investigated in 42 adults (21 to 85 years of age) with varying degrees of renal impairment. Following the oral administration of a single 1 gram dose of azithromycin (4 x 250 mg capsules), mean C max and AUC 0-120 increased by 5.1% and 4.2%, respectively, in subjects with mild to moderate renal impairment (GFR 10 to 80 mL/min) compared to subjects with normal renal function (GFR > 80 mL/min). The mean C max and AUC 0-120 increased 61% and 35%, respectively, in subjects with severe renal impairment (GFR < 10 mL/min) compared to subjects with normal renal function (GFR > 80 mL/min). Patients with Hepatic Impairment The pharmacokinetics of azithromycin in subjects with hepatic impairment has not been established. Male and Female Patients There are no significant differences in the disposition of azithromycin between male and female subjects. No dosage adjustment is recommended based on gender. Geriatric Patients Pharmacokinetic parameters in older volunteers (65 to 85 years old) were similar to those in young adults (18 to 40 years old) for the 5-day therapeutic regimen. Dosage adjustment does not appear to be necessary for older patients with normal renal and hepatic function receiving treatment with this dosage regimen [see Geriatric Use ( 8.5 )] . Pediatric Patients In two clinical studies, azithromycin for oral suspension was dosed at 10 mg/kg on day 1, followed by 5 mg/kg on days 2 through 5 in two groups of pediatric patients (aged 1 to 5 years and 5 to 15 years, respectively). The mean pharmacokinetic parameters on day 5 were C max =0.216 mcg/mL, T max =1.9 hours, and AUC 0-24 =1.822 mcg•hr/mL for the 1 to 5-year-old group and were C max =0.383 mcg/mL, T max =2.4 hours, and AUC 0-24 =3.109 mcg•hr/mL for the 5 to 15-year-old group. In another study, 33 pediatric patients received doses of 12 mg/kg/day (maximum daily dose 500 mg) for 5 days, of whom 31 patients were evaluated for azithromycin pharmacokinetics following a low fat breakfast. In this study, azithromycin concentrations were determined over a 24 hour period following the last daily dose. Patients weighing above 41.7 kg received the maximum adult daily dose of 500 mg. Seventeen patients (weighing 41.7 kg or less) received a total dose of 60 mg/kg. The following table shows pharmacokinetic data in the subset of pediatric patients who received a total dose of 60 mg/kg. Pharmacokinetic Parameter [mean (SD)] 5-Day Regimen (12 mg/kg for 5 days) N 17 C max (mcg/mL) 0.5 (0.4) T max (hr) 2.2 (0.8) AUC 0-24 (mcg⋅hr/mL) 3.9 (1.9) Single dose pharmacokinetics of azithromycin in pediatric patients given doses of 30 mg/kg have not been studied [see Dosage and Administration ( 2 )] . Drug Interaction Studies Drug interaction studies were performed with azithromycin and other drugs likely to be co-administered. The effects of co‑administration of azithromycin on the pharmacokinetics of other drugs are shown in Table 1 and the effects of other drugs on the pharmacokinetics of azithromycin are shown in Table 2 . Co-administration of azithromycin at therapeutic doses had a modest effect on the pharmacokinetics of the drugs listed in Table 1 . No dosage adjustment of drugs listed in Table 1 is recommended when co-administered with azithromycin. Co-administration of azithromycin with efavirenz or fluconazole had a modest effect on the pharmacokinetics of azithromycin. Nelfinavir significantly increased the C max and AUC of azithromycin. No dosage adjustment of azithromycin is recommended when administered with drugs listed in Table 2 [see Drug Interactions ( 7.3 )] . Table 1. Drug Interactions: Pharmacokinetic Parameters for Co-administered Drugs in the Presence of Azithromycin Co-Administered Drug Dose of Co-Administered Drug Dose of Azithromycin n Ratio (with/without azithromycin) of Co-administered Drug Pharmacokinetic Parameters (90% CI); No Effect=1.00 Mean C max Mean AUC Atorvastatin 10 mg/day for 8 days 500 mg/day orally on days 6-8 12 0.83 (0.63 to 1.08) 1.01 (0.81 to 1.25) Carbamazepine 200 mg/day for 2 days, then 200 mg twice a day for 18 days 500 mg/day orally for days 16-18 7 0.97 (0.88 to 1.06) 0.96 (0.88 to 1.06) Cetirizine 20 mg/day for 11 days 500 mg orally on day 7, then 250 mg/day on days 8-11 14 1.03 (0.93 to 1.14) 1.02 (0.92 to 1.13) Didanosine 200 mg orally twice a day for 21 days 1,200 mg/day orally on days 8-21 6 1.44 (0.85 to 2.43) 1.14 (0.83 to 1.57) Efavirenz 400 mg/day for 7 days 600 mg orally on day 7 14 1.04* 0.95* Fluconazole 200 mg orally single dose 1,200 mg orally single dose 18 1.04 (0.98 to 1.11) 1.01 (0.97 to 1.05) Indinavir 800 mg three times a day for 5 days 1,200 mg orally on day 5 18 0.96 (0.86 to 1.08) 0.90 (0.81 to 1.00) Midazolam 15 mg orally on day 3 500 mg/day orally for 3 days 12 1.27 (0.89 to 1.81) 1.26 (1.01 to 1.56) Nelfinavir 750 mg three times a day for 11 days 1,200 mg orally on day 9 14 0.90 (0.81 to 1.01) 0.85 (0.78 to 0.93) Sildenafil 100 mg on days 1 and 4 500 mg/day orally for 3 days 12 1.16 (0.86 to 1.57) 0.92 (0.75 to 1.12) Theophylline 4 mg/kg IV on days 1, 11, 25 500 mg orally on day 7, 250 mg/day on days 8-11 10 1.19 (1.02 to 1.40) 1.02 (0.86 to 1.22) Theophylline 300 mg orally twice a day for 15 days 500 mg orally on day 6, then 250 mg/day on days 7-10 8 1.09 (0.92 to 1.29) 1.08 (0.89 to 1.31) Triazolam 0.125 mg on day 2 500 mg orally on day 1, then 250 mg/day on day 2 12 1.06* 1.02* Trimethoprim/ Sulfamethoxazole 160 mg/800 mg/day orally for 7 days 1,200 mg orally on day 7 12 0.85 (0.75 to 0.97)/ 0.90 (0.78 to 1.03) 0.87 (0.80 to 0.95)/ 0.96 (0.88 to 1.03) Zidovudine 500 mg/day orally for 21 days 600 mg/day orally for 14 days 5 1.12 (0.42 to 3.02) 0.94 (0.52 to 1.70) Zidovudine 500 mg/day orally for 21 days 1,200 mg/day orally for 14 days 4 1.31 (0.43 to 3.97) 1.30 (0.69 to 2.43) * -90% Confidence interval not reported Table 2. Drug Interactions: Pharmacokinetic Parameters for Azithromycin in the Presence of Co-administered Drugs [see Drug Interactions ( 7 )] . Co-Administered Drug Dose of Co-Administered Drug Dose of Azithromycin n Ratio (with/without Co-adminis- tered Drug) of Azithromycin Pharmacokinetic Parameters (90% CI); No Effect=1.00 Mean C max Mean AUC Efavirenz 400 mg/day for 7 days 600 mg orally on day 7 14 1.22 (1.04 to 1.42) 0.92* Fluconazole 200 mg orally single dose 1,200 mg orally single dose 18 0.82 (0.66 to 1.02) 1.07 (0.94 to 1.22) Nelfinavir 750 mg three times a day for 11 days 1,200 mg orally on day 9 14 2.36 (1.77 to 3.15) 2.12 (1.80 to 2.50) * -90% Confidence interval not reported

Warnings and Precautions, Cardiovascular Death ( 5.5 ) 11/2021

Pediatric Use: Safety and effectiveness in the treatment of patients under 6 months of age have not been established. ( 8.4 ) Geriatric Use: Elderly patients may be more susceptible to development of torsades de pointes arrhythmias. ( 8.5 )

Serious (including fatal) allergic and skin reactions: Discontinue azithromycin if reaction occurs. ( 5.1 ) Hepatotoxicity: Severe, and sometimes fatal, hepatotoxicity has been reported. Discontinue azithromycin immediately if signs and symptoms of hepatitis occur. ( 5.2 ) Infantile Hypertrophic Pyloric Stenosis (IHPS): Following the use of azithromycin in neonates (treatment up to 42 days of life), IHPS has been reported. Direct parents and caregivers to contact their physician if vomiting or irritability with feeding occurs. ( 5.3 ) Prolongation of QT interval and cases of torsades de pointes have been reported. This risk which can be fatal should be considered in patients with certain cardiovascular disorders including known QT prolongation or history torsades de pointes , those with proarrhythmic conditions, and with other drugs that prolong the QT interval. ( 5.4 ) Cardiovascular Death: Some observational studies have shown an approximately two-fold increased short-term potential risk of acute cardiovascular death in adults exposed to azithromycin relative to other antibacterial drugs, including amoxicillin. Consider balancing this potential risk with treatment benefits when prescribing azithromycin. ( 5.5 ) Clostridioides difficile -Associated Diarrhea: Evaluate patients if diarrhea occurs. ( 5.6 ) Azithromycin may exacerbate muscle weakness in persons with myasthenia gravis. ( 5.7 )

LABEL

Risk Summary Azithromycin is present in human milk (see Data) . Non-serious adverse reactions have been reported in breastfed infants after maternal administration of azithromycin (see Clinical Considerations ) . There are no available data on the effects of azithromycin on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for azithromycin and any potential adverse effects on the breastfed infant from azithromycin or from the underlying maternal condition. Clinical Considerations Advise women to monitor the breastfed infant for diarrhea, vomiting, or rash. Data Azithromycin breastmilk concentrations were measured in 20 women after receiving a single 2 g oral dose of azithromycin during labor. Breastmilk samples collected on days 3 and 6 postpartum as well as 2 and 4 weeks postpartum revealed the presence of azithromycin in breastmilk up to 4 weeks after dosing. In another study, a single dose of azithromycin 500 mg was administered intravenously to 8 women prior to incision for cesarean section. Breastmilk (colostrum) samples obtained between 12 and 48 hours after dosing revealed that azithromycin persisted in breastmilk up to 48 hours.