LANSOPRAZOLE, AMOXICILLIN, CLARITHROMYCIN

Lansoprazole delayed-release capsules USP, amoxicillin capsules USP, and clarithromycin tablets USP consist of a daily administration card containing two lansoprazole 30 mg delayed-release capsules USP, four amoxicillin 500 mg capsules USP, and two clarithromycin 500 mg tablets USP, for oral administration. Lansoprazole Delayed-Release Capsules, USP The active ingredient in lansoprazole delayed-release capsules USP is lansoprazole, a proton pump inhibitor. Its empirical formula is C 16 H 14 F 3 N 3 O 2 S with a molecular weight of 369.37. Lansoprazole has the following structure: Lansoprazole USP is a white to brownish-white odorless crystalline powder which melts with decomposition at approximately 166°C. Lansoprazole is freely soluble in dimethylformamide; soluble in methanol; sparingly soluble in ethanol; slightly soluble in ethyl acetate, dichloromethane and acetonitrile; very slightly soluble in ether; and practically insoluble in hexane and water. Each delayed-release capsule contains enteric-coated pellets consisting of 30 mg of lansoprazole USP (active ingredient) and the following inactive ingredients: acetone, hypromellose, isopropyl alcohol, light magnesium carbonate, methacrylic acid copolymer, polyethylene glycol, polysorbate 80, sugar spheres (which contain sucrose and corn starch), talc, and titanium dioxide. Components of the gelatin capsule include D&C Red No. 28, FD&C Blue No. 1, FD&C Red No. 40, gelatin, sodium lauryl sulfate, and titanium dioxide. Amoxicillin Capsules, USP Amoxicillin, is a penicillin class antibacterial, with a broad spectrum of bactericidal activity against many gram-positive and gram-negative microorganisms. Chemically it is (2 S , 5 R , 6 R )-6-[( R )-(-)-2-amino-2-( p -hydroxyphenyl)acetamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0] heptane-2-carboxylic acid trihydrate. The molecular formula is C 16 H 19 N 3 O 5 S•3H 2 O and the molecular weight of 419.45. Amoxicillin has the following structure: Amoxicillin capsules USP are intended for oral administration. The pink body with blue cap capsules contain amoxicillin trihydrate equivalent to 500 mg of amoxicillin USP. Inactive ingredients: Capsule shells - D&C Red No. 28, FD&C Blue No. 1, FD&C Red No. 40, gelatin, sodium lauryl sulfate and titanium dioxide; Capsule contents – magnesium stearate, microcrystalline cellulose. Meets USP Dissolution Test 2. Clarithromycin Tablets, USP Clarithromycin is a macrolide antimicrobial. Chemically, it is 6- O -methylerythromycin. The molecular formula is C 38 H 69 NO 13 , and the molecular weight is 747.96. Clarithromycin has the following structure: Clarithromycin USP is a white or almost white, crystalline powder. It is soluble in acetone, slightly soluble in methanol, ethanol, and acetonitrile, and practically insoluble in water. Each light yellow colored, oval shaped, biconvex film-coated immediate-release tablet contains 500 mg of clarithromycin USP and the following inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, hydroxypropyl cellulose, hypromellose, iron oxide yellow, magnesium stearate, microcrystalline cellulose, povidone, propylene glycol, sorbic acid, titanium dioxide, and vanillin. lansoprazole-amoxicillin-clarithromycin-structure-1.jpg lansoprazole-amoxicillin-clarithromycin-structure-2.jpg lansoprazole-amoxicillin-clarithromycin-structure-3.jpg

H. pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence The components in lansoprazole delayed-release capsules, amoxicillin capsules, and clarithromycin tablets are indicated for the treatment of patients with H. pylori infection and duodenal ulcer disease (active or one-year history of a duodenal ulcer) to eradicate H. pylori . Eradication of H. pylori has been shown to reduce the risk of duodenal ulcer recurrence (see CLINICAL STUDIES and DOSAGE AND ADMINISTRATION ). To reduce the development of drug-resistant bacteria and maintain the effectiveness of lansoprazole delayed-release capsules, amoxicillin capsules, and clarithromycin tablets and other antibacterial drugs, lansoprazole delayed-release capsules, amoxicillin capsules, and clarithromycin tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

H. pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence The recommended adult oral dose is 30 mg lansoprazole delayed-release capsules, 1 g amoxicillin, and 500 mg clarithromycin administered together twice daily (morning and evening) for 10 or 14 days (see INDICATIONS AND USAGE ). Lansoprazole delayed-release capsules, 30 mg, amoxicillin capsules, 500 mg, and clarithromycin tablets, 500 mg are not recommended in patients with creatinine clearance less than 30 mL/min.

Lansoprazole delayed-release capsules, amoxicillin capsules, and clarithromycin tablets are contraindicated in patients with known severe hypersensitivity to any component of the formulation of lansoprazole delayed-release capsules. Hypersensitivity reactions may include anaphylaxis, anaphylactic shock, angioedema, bronchospasm, acute interstitial nephritis, and urticaria (see ADVERSE REACTIONS ). Proton Pump Inhibitors (PPIs), including lansoprazole delayed-release capsules, are contraindicated with rilpivirine-containing products (see CLINICAL PHARMACOLOGY , Drug Interaction Studies ). A history of severe hypersensitivity reactions (e.g., anaphylaxis or Stevens-Johnson syndrome) to amoxicillin or other beta-lactam antibiotics (e.g., penicillins and cephalosporins) is a contraindication. Clarithromycin is contraindicated in patients with a known hypersensitivity to clarithromycin, erythromycin, or any of the macrolide antibiotics. Clarithromycin is contraindicated in patients with a history of cholestatic jaundice/hepatic dysfunction associated with prior use of clarithromycin. Clarithromycin is contraindicated with concomitant use of lurasidone due to the risk of an increase in lurasidone exposure and the potential for serious adverse reactions [(see PRECAUTIONS , Drug Interactions ) (7)]. Clarithromycin should not be given to patients with history of QT prolongation or ventricular cardiac arrhythmia, including torsades de pointes. Concomitant administration of clarithromycin, a component of lansoprazole delayed-release capsules, amoxicillin capsules, and clarithromycin tablets, and any of the following drugs is contraindicated: cisapride, pimozide, astemizole, terfenadine, ergotamine or dihydroergotamine (see PRECAUTIONS, Drug Interactions ). There have been post-marketing reports of drug interactions when clarithromycin and/or erythromycin are coadministered with cisapride, pimozide, astemizole, or terfenadine resulting in cardiac arrhythmias (QT prolongation, ventricular tachycardia, ventricular fibrillation, and torsades de pointes ) most likely due to inhibition of metabolism of these drugs by erythromycin and clarithromycin. Fatalities have been reported. Concomitant administration of clarithromycin and colchicine is contraindicated in patients with renal or hepatic impairment. Clarithromycin should not be used concomitantly with HMG-CoA reductase inhibitors (statins) that are extensively metabolized by CYP3A4 (lovastatin or simvastatin), due to the increase risk of myopathy, including rhabdomyolysis (see WARNINGS ).

LANSOPRAZOLE DELAYED-RELEASE CAPSULES, AMOXICILLIN CAPSULES, AND CLARITHROMYCIN TABLETS Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. The most common adverse reactions (≥3%) reported in clinical trials when all three components of this therapy were given concomitantly for 14 days are listed in Table 8. Table 8: Adverse Reactions Most Frequently Reported in Clinical Trials (≥3%) Adverse Reaction Triple Therapy n = 138 (%) Diarrhea 7.0 Headache 6.0 Taste Perversion 5.0 The additional adverse reactions which were reported as possibly or probably related to treatment (less than 3%) in clinical trials when all three components of this therapy were given concomitantly are listed below and divided by body system: Body as a Whole - abdominal pain Digestive System - dark stools, dry mouth/thirst, glossitis, rectal itching, nausea, oral moniliasis, stomatitis, tongue discoloration, tongue disorder, vomiting Musculoskeletal System - myalgia Nervous System - confusion, dizziness Respiratory System - respiratory disorders Skin and Appendages - skin reactions Urogenital System - vaginitis, vaginal moniliasis There were no statistically significant differences in the frequency of reported adverse events between the 10 and 14 day triple therapy regimens. Lansoprazole Delayed-Release Capsules The following adverse reactions from the labeling for lansoprazole delayed-release capsules are provided for information: Worldwide, over 10,000 patients have been treated with lansoprazole delayed-release capsules in Phase 2 or Phase 3 clinical trials involving various dosages and durations of treatment. In general, lansoprazole delayed-release capsules treatment has been well-tolerated in both short-term and long-term trials. Incidence in Clinical Trials The following adverse events were reported by the treating physician to have a possible or probable relationship to drug in 1% or more of lansoprazole delayed-release capsules-treated patients and occurred at a greater rate in lansoprazole delayed-release capsules-treated patients than placebo-treated patients: Table 9: Incidence of Possibly or Probably Treatment-Related Adverse Reactions in Short-Term, Placebo-Controlled Lansoprazole Delayed-Release Capsules Studies Body System/Adverse Event Lansoprazole Delayed-Release Capsules (N=2768) % Placebo (N=1023) % Body as a Whole Abdominal Pain 2.1 1.2 Digestive System Constipation 1.0 0.4 Diarrhea 3.8 2.3 Nausea 1.3 1.2 Headache was also seen at greater than 1% incidence but was more common on placebo. The incidence of diarrhea was similar between patients who received placebo and patients who received 30 mg of lansoprazole delayed-release capsules, but higher in the patients who received 60 mg of lansoprazole delayed-release capsules (2.9%, 4.2%, and 7.4%, respectively). The most commonly reported possibly or probably treatment-related adverse event during maintenance therapy was diarrhea. Additional adverse experiences occurring in less than 1% of patients or subjects who received lansoprazole delayed-release capsules in domestic trials are shown below: Body as a Whole – abdomen enlarged, allergic reaction, asthenia, back pain, candidiasis, carcinoma, chest pain (not otherwise specified), chills, edema, fever, flu syndrome, halitosis, infection (not otherwise specified), malaise, neck pain, neck rigidity, pain, pelvic pain Cardiovascular System – angina, arrhythmia, bradycardia, cerebrovascular accident/cerebral infarction, hypertension/hypotension, migraine, myocardial infarction, palpitations, shock (circulatory failure), syncope, tachycardia, vasodilation Digestive System – abnormal stools, anorexia, bezoar, cardiospasm, cholelithiasis, colitis, dry mouth, dyspepsia, dysphagia, enteritis, eructation, esophageal stenosis, esophageal ulcer, esophagitis, fecal discoloration, flatulence, gastric nodules/fundic gland polyps, gastritis, gastroenteritis, gastrointestinal anomaly, gastrointestinal disorder, gastrointestinal hemorrhage, glossitis, gum hemorrhage, hematemesis, increased appetite, increased salivation, melena, mouth ulceration, nausea and vomiting, nausea and vomiting and diarrhea, gastrointestinal moniliasis, rectal disorder, rectal hemorrhage, stomatitis, tenesmus, thirst, tongue disorder, ulcerative colitis, ulcerative stomatitis Endocrine System – diabetes mellitus, goiter, hypothyroidism Hemic and Lymphatic System – anemia, hemolysis, lymphadenopathy Metabolism and Nutritional Disorders – avitaminosis, gout, dehydration, hyperglycemia/hypoglycemia, peripheral edema, weight gain/loss Musculoskeletal System – arthralgia, arthritis, bone disorder, joint disorder, leg cramps, musculoskeletal pain, myalgia, myasthenia, ptosis, synovitis Nervous System – abnormal dreams, agitation, amnesia, anxiety, apathy, confusion, convulsion, dementia, depersonalization, depression, diplopia, dizziness, emotional lability, hallucinations, hemiplegia, hostility aggravated, hyperkinesia, hypertonia, hypesthesia, insomnia, libido decreased/increased, nervousness, neurosis, paresthesia, sleep disorder, somnolence, thinking abnormality, tremor, vertigo Respiratory System – asthma, bronchitis, cough increased, dyspnea, epistaxis, hemoptysis, hiccup, laryngeal neoplasia, lung fibrosis, pharyngitis, pleural disorder, pneumonia, respiratory disorder, upper respiratory inflammation/infection, rhinitis, sinusitis, stridor Skin and Appendages – acne, alopecia, contact dermatitis, dry skin, fixed eruption, hair disorder, maculopapular rash, nail disorder, pruritus, rash, skin carcinoma, skin disorder, sweating, urticaria Special Senses – abnormal vision, amblyopia, blepharitis, blurred vision, cataract, conjunctivitis, deafness, dry eyes, ear/eye disorder, eye pain, glaucoma, otitis media, parosmia, photophobia, retinal degeneration/disorder, taste loss, taste perversion, tinnitus, visual field defect Urogenital System – abnormal menses, breast enlargement, breast pain, breast tenderness, dysmenorrhea, dysuria, gynecomastia, impotence, kidney calculus, kidney pain, leukorrhea, menorrhagia, menstrual disorder, penis disorder, polyuria, testis disorder, urethral pain, urinary frequency, urinary retention, urinary tract infection, urinary urgency, urination impaired, vaginitis Postmarketing Additional adverse experiences have been reported since lansoprazole delayed-release capsules has been marketed. The majority of these cases are foreign-sourced and a relationship to lansoprazole delayed-release capsules has not been established. Because these events were reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events are listed below by COSTART body system: Body as a Whole – anaphylactic/anaphylactoid reactions, systemic lupus erythematosus Digestive System – hepatotoxicity, pancreatitis, vomiting Hemic and Lymphatic System – agranulocytosis, aplastic anemia, hemolytic anemia, leukopenia, neutropenia, pancytopenia, thrombocytopenia, and thrombotic thrombocytopenic purpura Infections and infestations – Clostridium difficile – associated diarrhea Metabolism and Nutritional Disorders – hypomagnesemia, hyponatremia. Musculoskeletal System – bone fracture, myositis Skin and Appendages – severe dermatologic reactions including erythema multiforme, SJS, TEN (some fatal), DRESS, AGEP cutaneous lupus erythematosus Special Senses – speech disorder Urogenital System – interstitial nephritis, urinary retention, erectile dysfunction Amoxicillin The following adverse reactions from the labeling for amoxicillin are provided for information: The most common adverse reactions (>1%) observed in clinical trials of amoxicillin capsules were diarrhea, rash, vomiting and nausea. The most frequently reported adverse events for patients who received triple therapy (amoxicillin/clarithromycin/lansoprazole) were diarrhea (7%), headache (6%), and taste perversion (5%). Infections and Infestations – Mucocutaneous candidiasis Gastrointestinal - Drug-induced enterocolitis syndrome (DIES), black hairy tongue, and hemorrhagic/pseudomembranous colitis. Onset of pseudomembranous colitis symptoms may occur during or after antibiotic treatment (see WARNINGS ). Hypersensitivity Reactions – Anaphylaxis (see WARNINGS ), serum sickness-like reactions, erythematous maculopapular rashes, erythema multiforme, Stevens-Johnson Syndrome, exfoliative dermatitis, toxic epidermal necrolysis, acute generalized exanthematous pustulosis, linear IgA bullous dermatosis, hypersensitivity vasculitis and urticaria have been reported. Liver – A moderate rise in AST and/or ALT has been noted, but the significance of this finding is unknown. Hepatic dysfunction including cholestatic jaundice, hepatic cholestasis and acute cytolytic hepatitis have been reported. Renal – Crystalluria has also been reported (see OVERDOSAGE ). Hemic and Lymphatic Systems – Anemia, including hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, leukopenia and agranulocytosis have been reported. These reactions are usually reversible on discontinuation of therapy and are believed to be hypersensitivity phenomena. Central Nervous System – Reversible hyperactivity, agitation, anxiety, insomnia, confusion, behavioral changes, and/or dizziness have been reported rarely. Miscellaneous – Tooth discoloration (brown, yellow, or gray staining) has been rarely reported. Most reports occurred in pediatric patients. Discoloration was reduced or eliminated with brushing or dental cleaning in most cases. Clarithromycin The following adverse reactions from the labeling for clarithromycin are provided for information: The most frequent and common adverse reactions related to clarithromycin therapy for both adult and pediatric populations are abdominal pain, diarrhea, nausea, vomiting, and dysgeusia. These adverse reactions are consistent with the known safety profile of macrolide antibiotics. There was no significant difference in the incidence of these gastrointestinal adverse reactions during clinical trials between the patient population with or without preexisting mycobacterial infections. Adverse Reactions Observed During Clinical Trials of Clarithromycin The following adverse reactions were observed in clinical trials with clarithromycin at a rate greater than or equal to 1%: Gastrointestinal Disorders – Diarrhea, vomiting, dyspepsia, nausea, abdominal pain Hepatobiliary Disorders – Liver function test abnormal Immune System Disorders – Anaphylactoid reaction Infections and Infestations – Candidiasis Nervous System Disorders – Dysgeusia, headache Psychiatric Disorders – Insomnia Skin and Subcutaneous Tissue Disorders – Rash Other Adverse Reactions Observed During Clinical Trials of Clarithromycin The following adverse reactions were observed in clinical trials with clarithromycin at a rate less than 1%: Blood and Lymphatic System Disorders – Leukopenia, neutropenia, thrombocythemia, eosinophilia Cardiac Disorders – Electrocardiogram QT prolonged, cardiac arrest, atrial fibrillation, extrasystoles, palpitations Ear and Labyrinth Disorders – Vertigo, tinnitus, hearing impaired Gastrointestinal Disorders – Stomatitis, glossitis, esophagitis, gastroesophageal reflux disease, gastritis, proctalgia, abdominal distention, constipation, dry mouth, eructation, flatulence General Disorders and Administration Site Conditions – Malaise, pyrexia, asthma, chest pain, chills, fatigue Hepatobiliary Disorders – Cholestasis, hepatitis Immune System Disorders – Hypersensitivity Infections and Infestations – Cellulitis, gastroenteritis, infection, vaginal infection Investigations – Blood bilirubin increased, blood alkaline phosphatase increased, blood lactate dehydrogenase increased, albumin globulin ratio abnormal Metabolism and Nutrition Disorders – Anorexia, decreased appetite Musculoskeletal and Connective Tissue Disorders – Myalgia, muscle spasms, nuchal rigidity Nervous System Disorders – Dizziness, tremor, loss of consciousness, dyskinesia, somnolence Psychiatric Disorders – Anxiety, nervousness Renal and Urinary Disorders – Blood creatinine increased, blood urea increased Respiratory, Thoracic and Mediastinal Disorders – Asthma, epistaxis, pulmonary embolism Skin and Subcutaneous Tissue Disorders – Urticaria, dermatitis bollus, pruritus, hyperhidrosis, rash maculopapular The following adverse reactions have been identified during post approval use of clarithromycin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Blood and Lymphatic System Disorders – Thrombocytopenia, agranulocytosis Cardiac Disorders – Torsades de pointes , ventricular tachycardia, ventricular arrhythmia Ear and Labyrinth Disorders – Deafness was reported chiefly in elderly women and was usually reversible. Gastrointestinal Disorders – Pancreatitis acute, tongue discoloration, tooth discoloration was reported and was usually reversible with professional cleaning upon discontinuation of the drug. Hepatobiliary Disorders – Hepatic failure, jaundice hepatocellular. Adverse reactions related to hepatic dysfunction have been reported with clarithromycin (see WARNINGS , Hepatotoxicity ) Immune System Disorders – Anaphylactic reaction Infections and Infestations – Pseudomembranous colitis Investigations – Prothrombin time prolonged, white blood cell count decreased, international normalized ratio increased. Abnormal urine color has been reported, associated with hepatic failure. Metabolism and Nutrition Disorders – Hypoglycemia has been reported in patients taking oral hypoglycemic agents or insulin. Musculoskeletal and Connective Tissue Disorders – Myopathy, rhabdomyolysis was reported and in some of the reports, clarithromycin was administered concomitantly with statins, fibrates, colchicines or allopurinol (see CONTRAINDICATIONS and WARNINGS ). Nervous System Disorders – Convulsion, ageusia, parosmia, anosmia, paresthesia Psychiatric Disorders – Psychotic disorder, confusional state, depersonalization, depression, disorientation, manic behavior, hallucination, abnormal behavior, abnormal dreams. These disorders usually resolve upon discontinuation of the drug. There are no data on the effect of clarithromycin on the ability to drive or use machines. The potential for dizziness, vertigo, confusion and disorientation, which may occur with the medication, should be taken into account before patients drive or use machines. Renal and Urinary Disorders – Nephritis interstitial, renal failure Skin and Subcutaneous Tissue Disorders – Stevens-Johnson Syndrome, toxic epidermal necrolysis, drug rash with eosinophilia and systemic symptoms (DRESS), Henoch-Schonlein purpura, acne Vascular Disorders – Hemorrhage There have been reports of colchicine toxicity with concomitant use of clarithromycin and colchicine, especially in the elderly, some of which occurred in patients with renal insufficiency. Deaths have been reported in some such patients (see WARNINGS and PRECAUTIONS ). Laboratory Values Lansoprazole Delayed-Release Capsules The following changes in laboratory parameters in patients who received lansoprazole delayed-release capsules were reported as adverse reactions: Abnormal liver function tests, increased SGOT (AST), increased SGPT (ALT), increased creatinine, increased alkaline phosphatase, increased globulins, increased GGTP, increased/decreased/abnormal WBC, abnormal AG ratio, abnormal RBC, bilirubinemia, blood potassium increased, blood urea increased, crystal urine present, eosinophilia, hemoglobin decreased, hyperlipemia, increased/decreased electrolytes, increased/decreased cholesterol, increased glucocorticoids, increased LDH, increased/decreased/abnormal platelets, increased gastrin levels and positive fecal occult blood. Urine abnormalities such as albuminuria, glycosuria, and hematuria were also reported. In the placebo-controlled studies, when SGOT (AST) and SGPT (ALT) were evaluated, 0.4% (4/978) and 0.4% (11/2677) patients, who received placebo and lansoprazole delayed-release capsules, respectively, had enzyme elevations greater than three times the upper limit of normal range at the final treatment visit. None of these patients who received lansoprazole delayed-release capsules reported jaundice at any time during the study.

No drug interaction studies have been conducted specifically with lansoprazole delayed-release capsules, amoxicillin capsules, and clarithromycin tablets. The following drug interactions are for the individual drug components: lansoprazole, amoxicillin, and clarithromycin. Therefore, the decision to adjust dosage should depend on the clinician’s assessment of among other things, the cumulative or net effect of the drug components of lansoprazole delayed-release capsules, amoxicillin capsules, and clarithromycin tablets. Lansoprazole Delayed-Release Capsules Tables 5 and 6 include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with lansoprazole delayed-release capsules and instructions for preventing or managing them. Consult the labeling of concomitantly used drugs to obtain further information about interactions with PPIs. Table 5. Clinically Relevant Interactions Affecting Drugs Coadministered with Lansoprazole Delayed-release Capsules and Interactions with Diagnostics Antiretrovirals Clinical Impact: The effect of PPIs on antiretroviral drugs is variable. The clinical importance and the mechanisms behind these interactions are not always known. Decreased exposure of some antiretroviral drugs (e.g., rilpivirine, atazanavir, and nelfinavir) when used concomitantly with lansoprazole may reduce antiviral effect and promote the development of drug resistance. Increased exposure of other antiretroviral drugs (e.g., saquinavir) when used concomitantly with lansoprazole may increase toxicity of the antiretroviral drugs. There are other antiretroviral drugs which do not result in clinically relevant interactions with lansoprazole. Intervention: Rilpivirine-containing products: Concomitant use with lansoprazole is contraindicated (see CONTRAINDICATIONS ). See prescribing information. Atazanavir : See prescribing information for atazanavir for dosing information. Nelfinavir : Avoid concomitant use with lansoprazole. See prescribing information for nelfinavir. Saquinavir : See the prescribing information for saquinavir and monitor for potential saquinavir toxicities. Other antiretrovirals : See prescribing information. Warfarin Clinical Impact: Increased INR and prothrombin time in patients receiving PPIs and warfarin concomitantly. Increases in INR and prothrombin time may lead to abnormal bleeding and even death. Intervention: Monitor INR and prothrombin time. Dose adjustment of warfarin may be needed to maintain target INR range. See prescribing information for warfarin. Methotrexate Clinical Impact: Concomitant use of PPIs with methotrexate (primarily at high dose) may elevate and prolong serum concentrations of methotrexate and/or its metabolite hydroxymethotrexate, possibly leading to methotrexate toxicities. No formal drug interaction studies of high-dose methotrexate with PPIs have been conducted (see WARNINGS ). Intervention: A temporary withdrawal of lansoprazole may be considered in some patients receiving high-dose methotrexate. Digoxin Clinical Impact: Potential for increased exposure of digoxin. Intervention: Monitor digoxin concentrations. Dose adjustment of digoxin may be needed to maintain therapeutic drug concentrations. See prescribing information for digoxin. Theophylline Clinical Impact: Increased clearance of theophylline (see CLINICAL PHARMACOLOGY ). Intervention: Individual patients may require additional titration of their theophylline dosage when lansoprazole is started or stopped to ensure clinically effective blood concentrations. Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Lansoprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity. Intervention: Mycophenolate mofetil (MMF): Coadministration of PPIs in healthy subjects and in transplant patients receiving MMF has been reported to reduce the exposure to the active metabolite, mycophenolic acid (MPA), possibly due to a decrease in MMF solubility at an increased gastric pH. The clinical relevance of reduced MPA exposure on organ rejection has not been established in transplant patients receiving lansoprazole delayed-release capsules and MMF. Use lansoprazole delayed-release capsules with caution in transplant patients receiving MMF. See the prescribing information for other drugs dependent on gastric pH for absorption. Combination Therapy with Clarithromycin and Amoxicillin Clinical Impact: Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions, including potentially fatal arrhythmias, and are contraindicated. Amoxicillin also has drug interactions. Intervention: See CONTRAINDICATIONS , WARNINGS and PRECAUTIONS in prescribing information for clarithromycin. See Drug Interactions in prescribing information for amoxicillin. Tacrolimus Clinical Impact: Potentially increased exposure of tacrolimus, especially in transplant patients who are intermediate or poor metabolizers of CYP2C19. Intervention: Monitor tacrolimus whole blood trough concentrations. Dose adjustment of tacrolimus may be needed to maintain therapeutic drug concentrations. See prescribing information for tacrolimus. Interactions with Investigations of Neuroendocrine Tumors Clinical Impact: CgA levels increase secondary to PPI-induced decreases in gastric acidity. The increased CgA level may cause false positive results in diagnostic investigations for neuroendocrine tumors (see WARNINGS , CLINICAL PHARMACOLOGY ). Intervention: Temporarily stop lansoprazole treatment at least 14 days before assessing CgA levels and consider repeating the test if initial CgA levels are high. If serial tests are performed (e.g., for monitoring), the same commercial laboratory should be used for testing, as reference ranges between tests may vary. Interaction with Secretin Stimulation Test Clinical Impact: Hyper-response in gastrin secretion in response to secretin stimulation test, falsely suggesting gastrinoma. Intervention: Temporarily stop lansoprazole treatment at least 28 days before assessing to allow gastrin levels to return to baseline (see CLINICAL PHARMACOLOGY ). False Positive Urine Tests for THC Clinical Impact: There have been reports of false positive urine screening tests for tetrahydrocannabinol (THC) in patients receiving PPIs. Intervention: An alternative confirmatory method should be considered to verify positive results. Table 6. Clinically Relevant Interactions Affecting Lansoprazole Delayed-release Capsules When Coadministered with Other Drugs CYP2C19 OR CYP3A4 Inducers Clinical Impact: Decreased exposure of lansoprazole when used concomitantly with strong inducers (see CLINICAL PHARMACOLOGY ). Intervention: St John's Wort, rifampin : Avoid concomitant use with lansoprazole. Ritonavir-containing products : See prescribing information. CYP2C19 or CYP3A4 Inhibitors Clinical Impact: Increased exposure of lansoprazole is expected when used concomitantly with strong inhibitors (see CLINICAL PHARMACOLOGY ). Intervention: Voriconazole : See prescribing information. Sucralfate Clinical Impact: Decreased and delayed absorption of lansoprazole (see CLINICAL PHARMACOLOGY ). Intervention: Take lansoprazole delayed-release capsules at least 30 minutes prior to sucralfate (see CLINICAL PHARMACOLOGY ). Amoxicillin Probenecid Probenecid decreases the renal tubular secretion of amoxicillin. Concurrent use of amoxicillin and probenecid may result in increased and prolonged blood levels of amoxicillin. Antibiotics Chloramphenicol, macrolides, sulfonamides, and tetracyclines may interfere with bactericidal effects of penicillin. This has been demonstrated in vitro ; however, the clinical significance of this interaction is not well documented. Amoxicillin may affect the gut flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral estrogen/progesterone contraceptives. Table 7. Clinically Significant Drug Interactions with Clarithromycin Tablets Drugs That Are Affected By Clarithromycin tablets Drug(s) with Pharmacokinetics Affected by Clarithromycin tablets Recommendation Comments Antiarrhythmics: Disopyramide Quinidine Dofetilide Amiodarone Sotalol Procainamide Not Recommended Disopyramide, Quinidine : There have been postmarketing reports of torsades de pointes occurring with concurrent use of clarithromycin and quinidine or disopyramide. Electrocardiograms should be monitored for QTc prolongation during coadministration of clarithromycin with these drugs (see WARNINGS ). Serum concentrations of these medications should also be monitored. There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with disopyramide and quinidine. There have been postmarketing reports of hypoglycemia with the concomitant administration of clarithromycin and disopyramide. Therefore, blood glucose levels should be monitored during concomitant administration of clarithromycin and disopyramide. Digoxin Use With Caution Digoxin : Digoxin is a substrate for P-glycoprotein (Pgp) and clarithromycin is known to inhibit Pgp. When clarithromycin and digoxin are coadministered, inhibition of Pgp by clarithromycin may lead to increased exposure of digoxin. Elevated digoxin serum concentrations in patients receiving clarithromycin and digoxin concomitantly have been reported in postmarketing surveillance. Some patients have shown clinical signs consistent with digoxin toxicity, including potentially fatal arrhythmias. Monitoring of serum digoxin concentrations should be considered, especially for patients with digoxin concentrations in the upper therapeutic range. Oral Anticoagulants: Warfarin Use With Caution Oral anticoagulants : Spontaneous reports in the postmarketing period suggest that concomitant administration of clarithromycin and oral anticoagulants may potentiate the effects of the oral anticoagulants. Prothrombin times should be carefully monitored while patients are receiving clarithromycin and oral anticoagulants simultaneously (see WARNINGS ). Antiepileptics: Carbamazepine Use With Caution Carbamazepine : Concomitant administration of single doses of clarithromycin and carbamazepine has been shown to result in increased plasma concentrations of carbamazepine. Blood level monitoring of carbamazepine may be considered. Increased serum concentrations of carbamazepine were observed in clinical trials with clarithromycin. There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with carbamazepine. Antifungals: Itraconazole Use With Caution Itraconazole : Both clarithromycin and itraconazole are substrates and inhibitors of CYP3A, potentially leading to a bi-directional drug interaction when administered concomitantly (see also Itraconazole under "Drugs That Affect Clarithromycin Tablets" in the table below). Clarithromycin may increase the plasma concentrations of itraconazole. Patients taking itraconazole and clarithromycin concomitantly should be monitored closely for signs or symptoms of increased or prolonged adverse reactions. Fluconazole No Dose Adjustment Fluconazole : No dosage adjustment of clarithromycin is necessary when coadministered with fluconazole. Anti-Gout Agents: Colchicine (in patients with renal or hepatic impairment) Contraindicated Colchicine : Colchicine is a substrate for both CYP3A and the efflux transporter, P-glycoprotein (Pgp). Clarithromycin and other macrolides are known to inhibit CYP3A and Pgp. The dose of colchicine should be reduced when coadministered with clarithromycin in patients with normal renal and hepatic function (see CONTRAINDICATIONS , WARNINGS ). Colchicine (in patients with normal renal and hepatic function) Use With Caution Antipsychotics: Pimozide Contraindicated Pimozide : (see CONTRAINDICATIONS ). Lurasidone Lurasidone : (see CONTRAINDICATIONS ). Quetiapine Quetiapine : Quetiapine is a substrate for CYP3A4, which is inhibited by clarithromycin. Coadministration with clarithromycin could result in increased quetiapine exposure and possible quetiapine related toxicities. There have been postmarketing reports of somnolence, orthostatic hypotension, altered state of consciousness, neuroleptic malignant syndrome, and QT prolongation during concomitant administration. Refer to quetiapine prescribing information for recommendations on dose reduction if coadministered with CYP3A4 inhibitors such as clarithromycin. Antispasmodics: Tolterodine (patients deficient in CYP2D6 activity) Use With Caution Tolterodine : The primary route of metabolism for tolterodine is via CYP2D6. However, in a subset of the population devoid of CYP2D6, the identified pathway of metabolism is via CYP3A. In this population subset, inhibition of CYP3A results in significantly higher serum concentrations of tolterodine. Tolterodine 1 mg twice daily is recommended in patients deficient in CYP2D6 activity (poor metabolizers) when coadministered with clarithromycin. Antivirals: Atazanavir Use With Caution Atazanavir : Both clarithromycin and atazanavir are substrates and inhibitors of CYP3A, and there is evidence of a bi-directional drug interaction (see Atazanavir under "Drugs That Affect Clarithromycin Tablets" in the table below). Saquinavir (in patients with decreased renal function) Saquinavir : Both clarithromycin and saquinavir are substrates and inhibitors of CYP3A and there is evidence of a bi-directional drug interaction (see Saquinavir under “Drugs That Affect Clarithromycin Tablets” in the table below). Ritonavir Etravirine Ritonavir, Etravirine : (see Ritonavir and Etravirine under "Drugs That Affect Clarithromycin Tablets" in the table below). Maraviroc Maraviroc : Clarithromycin may result in increases in maraviroc exposures by inhibition of CYP3A metabolism. See Selzentry ® prescribing information for dose recommendation when given with strong CYP3A inhibitors such as clarithromycin. Boceprevir (in patients with normal renal function) No Dose Adjustment Boceprevir : Both clarithromycin and boceprevir are substrates and inhibitors of CYP3A, potentially leading to a bi-directional drug interaction when coadministered. No dose adjustments are necessary for patients with normal renal function (see Victrelis ® prescribing information). Didanosine Zidovudine Zidovudine : Simultaneous oral administration of clarithromycin immediate-release tablets and zidovudine to HIV-infected adult patients may result in decreased steady-state zidovudine concentrations. Administration of clarithromycin and zidovudine should be separated by at least two hours. The impact of coadministration of clarithromycin extended-release tablets or granules and zidovudine has not been evaluated. Calcium Channel Blockers: Verapamil Use With Caution Verapamil : Hypotension, bradyarrhythmias, and lactic acidosis have been observed in patients receiving concurrent verapamil (see WARNINGS ). Amlodipine Diltiazem Amlodipine, Diltiazem : (see WARNINGS ). Nifedipine Nifedipine : Nifedipine is a substrate for CYP3A. Clarithromycin and other macrolides are known to inhibit CYP3A. There is potential of CYP3A-mediated interaction between nifedipine and clarithromycin. Hypotension and peripheral edema were observed when clarithromycin was taken concomitantly with nifedipine (see WARNINGS ). Ergot Alkaloids: Ergotamine Dihydroergotamine Contraindicated Ergotamine, Dihydroergotamine : Postmarketing reports indicate that coadministration of clarithromycin with ergotamine or dihydroergotamine has been associated with acute ergot toxicity characterized by vasospasm and ischemia of the extremities and other tissues including the central nervous system (see CONTRAINDICATIONS ). Gastroprokinetic Agents: Cisapride Contraindicated Cisapride : (see CONTRAINDICATIONS ). HMG-CoA Reductase Inhibitors: Lovastatin Simvastatin Contraindicated Lovastatin, Simvastatin, Atorvastatin, Pravastatin, Fluvastatin : (see CONTRAINDICATIONS , WARNINGS ). Atorvastatin Pravastatin Use With Caution Fluvastatin No Dose Adjustment Hypoglycemic Agents: Nateglinide Pioglitazone Repaglinide Rosiglitazone Use With Caution Nateglinide, Pioglitazone, Repaglinide, Rosiglitazone: (see WARNINGS , ADVERSE REACTIONS ). Insulin Insulin : (see WARNINGS , ADVERSE REACTIONS ). Immunosuppressants: Cyclosporine Use With Caution Cyclosporine : There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with cyclosporine. Tacrolimus Tacrolimus : There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with tacrolimus. Phosphodiesterase Inhibitors: Sildenafil Tadalafil Vardenafil Use With Caution Sildenafil, Tadalafil, Vardenafil : Each of these phosphodiesterase inhibitors is primarily metabolized by CYP3A, and CYP3A will be inhibited by concomitant administration of clarithromycin. Coadministration of clarithromycin with sildenafil, tadalafil, or vardenafil will result in increased exposure of these phosphodiesterase inhibitors. Coadministration of these phosphodiesterase inhibitors with clarithromycin is not recommended. Increased systemic exposure of these drugs may occur with clarithromycin; reduction of dosage for phosphodiesterase inhibitors should be considered (see their respective prescribing information). Proton Pump Inhibitors: Omeprazole No Dose Adjustment Omeprazole : The mean 24 hour gastric pH value was 5.2 when omeprazole was administered alone and 5.7 when coadministered with clarithromycin as a result of increased omeprazole exposures (see also Omeprazole under "Drugs That Affect Clarithromycin Tablets" in the table below). Xanthine Derivatives: Theophylline Use With Caution Theophylline : Clarithromycin use in patients who are receiving theophylline may be associated with an increase of serum theophylline concentrations. Monitoring of serum theophylline concentrations should be considered for patients receiving high doses of theophylline or with baseline concentrations in the upper therapeutic range. Triazolobenzodiazepines and Other Related Benzodiazepines: Midazolam Use With Caution Midazolam : When oral midazolam is coadministered with clarithromycin, dose adjustments may be necessary and possible prolongation and intensity of effect should be anticipated (see WARNINGS ). Alprazolam Triazolam Triazolam, Alprazolam : Caution and appropriate dose adjustments should be considered when triazolam or alprazolam is coadministered with clarithromycin. There have been postmarketing reports of drug interactions and central nervous system (CNS) effects (e.g., somnolence and confusion) with the concomitant use of clarithromycin and triazolam. Monitoring the patient for increased CNS pharmacological effects is suggested. In postmarketing experience, erythromycin has been reported to decrease the clearance of triazolam and midazolam, and thus, may increase the pharmacologic effect of these benzodiazepines. Temazepam Nitrazepam Lorazepam No Dose Adjustment Temazepam, Nitrazepam, Lorazepam : For benzodiazepines which are not metabolized by CYP3A (e.g., temazepam, nitrazepam, lorazepam), a clinically important interaction with clarithromycin is unlikely. Cytochrome P450 Inducers: Rifabutin Use With Caution Rifabutin : Concomitant administration of rifabutin and clarithromycin resulted in an increase in rifabutin, and decrease in clarithromycin serum levels together with an increased risk of uveitis (see Rifabutin under "Drugs That Affect Clarithromycin Tablets" in the table below). Other Drugs Metabolized by CYP3A: Alfentanil Bromocriptine Cilostazol Methylprednisolone Vinblastine Phenobarbital St. John's Wort Use With Caution There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with alfentanil, methylprednisolone, cilostazol, bromocriptine, vinblastine, phenobarbital, and St. John's Wort. Other Drugs Metabolized by CYP450 Isoforms Other than CYP3A: Hexobarbital Phenytoin Valproate Use With Caution There have been postmarketing reports of interactions of clarithromycin with drugs not thought to be metabolized by CYP3A, including hexobarbital, phenytoin, and valproate. Drugs That Affect Clarithromycin Tablets Drug(s) that Affect the Pharmacokinetics of Clarithromycin Tablets Recommendation Comments Antifungals: Itraconazole Use With Caution Itraconazole : Itraconazole may increase the plasma concentrations of clarithromycin. Patients taking itraconazole and clarithromycin concomitantly should be monitored closely for signs or symptoms of increased or prolonged adverse reactions (see also Itraconazole under "Drugs That Are Affected By Clarithromycin Tablets" in the table above). Antivirals: Atazanavir Use With Caution Atazanavir : When clarithromycin is coadministered with atazanavir, the dose of clarithromycin should be decreased by 50%. Since concentrations of 14-OH clarithromycin are significantly reduced when clarithromycin is coadministered with atazanavir, alternative antibacterial therapy should be considered for indications other than infections due to Mycobacterium avium complex. Doses of clarithromycin greater than 1000 mg per day should not be coadministered with protease inhibitors. Ritonavir (in patients with decreased renal function) Ritonavir : Since concentrations of 14-OH clarithromycin are significantly reduced when clarithromycin is coadministered with ritonavir, alternative antibacterial therapy should be considered for indications other than infections due to Mycobacterium avium . Doses of clarithromycin greater than 1000 mg per day should not be coadministered with protease inhibitors. Saquinavir (in patients with decreased renal function) Saquinavir : When saquinavir is coadministered with ritonavir, consideration should be given to the potential effects of ritonavir on clarithromycin (refer to ritonavir above). Etravirine Etravirine : Clarithromycin exposure was decreased by etravirine; however, concentrations of the active metabolite, 14-OH-clarithromycin, were increased. Because 14-OH-clarithromycin has reduced activity against Mycobacterium avium complex (MAC), overall activity against this pathogen may be altered; therefore alternatives to clarithromycin should be considered for the treatment of MAC. Saquinavir (in patients with normal renal function) Ritonavir (in patients with normal renal function) No Dose Adjustment Proton Pump Inhibitors: Omeprazole Use With Caution Omeprazole : Clarithromycin concentrations in the gastric tissue and mucus were also increased by concomitant administration of omeprazole. Miscellaneous Cytochrome P450 Inducers: Efavirenz Nevirapine Rifampicin Rifabutin Rifapentine Use With Caution Inducers of CYP3A enzymes, such as efavirenz, nevirapine, rifampicin, rifabutin, and rifapentine will increase the metabolism of clarithromycin, thus decreasing plasma concentrations of clarithromycin, while increasing those of 14-OH-clarithromycin. Since the microbiological activities of clarithromycin and 14-OH-clarithromycin are different for different bacteria, the intended therapeutic effect could be impaired during concomitant administration of clarithromycin and enzyme inducers. Alternative antibacterial treatment should be considered when treating patients receiving inducers of CYP3A. There have been spontaneous or published reports of CYP3A based interactions of clarithromycin with rifabutin (see Rifabutin under "Drugs That Are Affected By Clarithromycin Tablets" in the table above).