NAPROXEN

Naproxen Tablets, USP Rx only DESCRIPTION Naproxen, USP is a propionic acid derivative related to the arylacetic acid group of nonsteroidal anti-inflammatory drugs. The chemical name for naproxen, USP is (S)-6-methoxy-α-methyl-2-naphthaleneacetic acid. It has the following structural formula: Naproxen, USP has a molecular weight of 230.26 and a molecular formula of C 14 H 14 O 3 . Naproxen, USP is an odorless, white to off-white crystalline substance. It is lipid-soluble, practically insoluble in water at low pH and freely soluble in water at high pH. The octanol/water partition coefficient of naproxen at pH 7.4 is 1.6 to 1.8. Naproxen tablets, USP are available as yellow tablets containing 250 mg of naproxen USP, pink tablets containing 375 mg of naproxen USP, and yellow tablets containing 500 mg of naproxen USP for oral administration. The inactive ingredients are croscarmellose sodium, povidone, iron oxide yellow, iron oxide red colloidal silicon dioxide and magnesium stearate. structure

Carefully consider the potential benefits and risks of naproxen tablets and other treatment options before deciding to use naproxen tablets. Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals (see WARNINGS: Gastrointestinal Bleeding, Ulceration, and Perforation) . Naproxen tablets are indicated: For the relief of the signs and symptoms of rheumatoid arthritis For the relief of the signs and symptoms of osteoarthritis For the relief of the signs and symptoms of ankylosing spondylitis For the relief of the signs and symptoms of juvenile arthritis Naproxen tablets are also indicated: For relief of the signs and symptoms of tendonitis For relief of the signs and symptoms of bursitis For relief of the signs and symptoms of acute gout For the management of pain For the management of primary dysmenorrhea

OVERDOSAGE Symptoms following acute NSAID overdosages have been typically limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which have been generally reversible with supportive care. Gastrointestinal bleeding has occurred. Hypertension, acute renal failure, respiratory depression, and coma have occurred, but were rare. Because naproxen sodium may be rapidly absorbed, high and early blood levels should be anticipated. A few patients have experienced convulsions, but it is not clear whether or not these were drug-related. It is not known what dose of the drug would be life threatening. (see WARNINGS; Cardiovascular Thrombotic Events, Gastrointestinal Bleeding, Ulceration, and Perforation, Hypertension , Renal Toxicity and Hyperkalemia ). Manage patients with symptomatic and supportive care following an NSAID overdosage. There are no specific antidotes. Hemodialysis does not decrease the plasma concentration of naproxen because of the high degree of its protein binding. Consider emesis and/or activated charcoal (60 to 100 g in adults, 1 to 2 g/kg of body weight in pediatric patients) and/or osmotic cathartic in symptomatic patients seen within four hours of ingestion or in patients with a large overdosage (5 to 10 times the recommended dosage). Forced diuresis, alkalinization of urine, hemodialysis, or hemoperfusion may not be useful due to high protein binding. For additional information about overdosage treatment contact a poison control center (1-800-222-1222). DOSAGE AND ADMINISTRATION Carefully consider the potential benefits and risks of naproxen tablets and other treatment options before deciding to use naproxen tablets. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS; Gastrointestinal Bleeding, Ulceration, and Perforation ). After observing the response to initial therapy with naproxen tablets, the dose and frequency should be adjusted to suit an individual patient’s needs. Different dose strengths and formulations (i.e., tablets, suspension) of the drug are not necessarily bioequivalent. This difference should be taken into consideration when changing formulation. Although naproxen tablets, naproxen suspension, naproxen delayed-released tablets, and naproxen sodium tablets all circulate in the plasma as naproxen, they have pharmacokinetic differences that may affect onset of action. Onset of pain relief can begin within 1 hour in patients taking naproxen. The recommended strategy for initiating therapy is to choose a formulation and a starting dose likely to be effective for the patient and then adjust the dosage based on observation of benefit and/or adverse events. A lower dose should be considered in patients with renal or hepatic impairment or in elderly patients (see WARNINGS; Hepatotoxicity , and Renal Toxicity and Hyperkalemia , and PRECAUTIONS ; Geriatric Use ). Geriatric Patients Studies indicate that although total plasma concentration of naproxen is unchanged, the unbound plasma fraction of naproxen is increased in the elderly. Caution is advised when high doses are required and some adjustment of dosage may be required in elderly patients. As with other drugs used in the elderly, it is prudent to use the lowest effective dose. Patients With Moderate to Severe Renal Impairment Naproxen-containing products are not recommended for use in patients with moderate to severe and severe renal impairment (creatinine clearance <30 mL/min) (see WARNINGS: Renal Effects ). Rheumatoid Arthritis, Osteoarthritis and Ankylosing Spondylitis Naproxen Tablets 250 mg or 375 mg or 500 mg twice daily twice daily twice daily During long-term administration, the dose of naproxen may be adjusted up or down depending on the clinical response of the patient. A lower daily dose may suffice for long-term administration. The morning and evening doses do not have to be equal in size and the administration of the drug more frequently than twice daily is not necessary. In patients who tolerate lower doses well, the dose may be increased to naproxen 1500 mg/day for limited periods of up to 6 months when a higher level of anti-inflammatory/analgesic activity is required. When treating such patients with naproxen 1500 mg/day, the physician should observe sufficient increased clinical benefits to offset the potential increased risk. The morning and evening doses do not have to be equal in size and administration of the drug more frequently than twice daily does not generally make a difference in response (see CLINICAL PHARMACOLOGY ). Juvenile Arthritis Naproxen tablets may not allow for the flexible dose titration needed in pediatric patients with juvenile arthritis. A liquid formulation may be more appropriate. In pediatric patients, doses of 5 mg/kg/day produced plasma levels of naproxen similar to those seen in adults taking 500 mg of naproxen (see Clinical Pharmacology ). The recommended total daily dose of naproxen is approximately 10 mg/kg given in 2 divided doses. One-half of the 250 mg tablet will be needed for dosing lower-weight children. Dosing with naproxen tablets is not appropriate for children weighing less than 25 kilograms. Management of Pain, Primary Dysmenorrhea, and Acute Tendonitis and Bursitis Because the sodium salt of naproxen is more rapidly absorbed, naproxen sodium is recommended for the management of acute painful conditions when prompt onset of pain relief is desired. Naproxen may also be used. The recommended starting dose of naproxen is 500 mg, followed by 500 mg every 12 hours or 250 mg every 6 to 8 hours as required. The initial total daily dose should not exceed 1250 mg of naproxen. Thereafter, the total daily dose should not exceed 1000 mg of naproxen. Acute Gout The recommended starting dose is 750 mg of naproxen tablets followed by 250 mg every 8 hours until the attack has subsided.

Naproxen tablets are contraindicated in the following patents: Known hypersensitivity (e.g., anaphylactic reactions and serious skin reactions) to naproxen or any components of the drug product (see WARNINGS ; Anaphylactic Reactions, Serious Skin Reactions) . History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. Severe, sometimes fatal, anaphylactic reactions to NSAIDs have been reported in such patients (see WARNINGS ; Anaphylactic Reactions, Exacerbation of Asthma Related to Aspirin Sensitivity) . In the setting of coronary artery bypass graft (CABG) surgery (see WARNINGS; Cardiovascular Thrombotic Events) .

Data Human Data There is some evidence to suggest that when inhibitors of prostaglandin synthesis are used to delay preterm labor there is an increased risk of neonatal complications such as necrotizing enterocolitis, patent ductus arteriosus and intracranial hemorrhage. Naproxen treatment given in late pregnancy to delay parturition has been associated with persistent pulmonary hypertension, renal dysfunction and abnormal prostaglandin E levels in preterm infants. Because of the known effects of nonsteroidal anti-inflammatory drugs on the fetal cardiovascular system (closure of ductus arteriosus), use during pregnancy (particularly starting at 30-weeks of gestation, or third trimester) should be avoided. Animal Data Reproduction studies have been performed in rats at 20 mg/kg/day (0.13 times the maximum recommended human daily dose of 1500 mg/day based on body surface area comparison), rabbits at 20 mg/kg/day (0.26 times the maximum recommended human daily dose, based on body surface area comparison), and mice at 170 mg/kg/day (0.6 times the maximum recommended human daily dose based on body surface area comparison) with no evidence of impaired fertility or harm to the fetus due to the drug. Based on animal data, prostaglandins have been shown to have an important role in endometrial vascular permeability, blastocyst implantation, and decidualization. In animal studies, administration of prostaglandin synthesis inhibitors such as naproxen resulted in increased pre- and post-implantation loss. Labor and Delivery There are no studies on the effects of naproxen tablets during labor or delivery. In animal studies, NSAIDS, including naproxen, inhibit prostaglandin synthesis, cause delayed parturition, and increase the incidence of stillbirth. Nursing Mothers The naproxen anion has been found in the milk of lactating women at a concentration equivalent to approximately 1% of maximum naproxen concentration in plasma. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for naproxen tablets and any potential adverse effects on the breastfed infant from the naproxen tablets or from the underlying maternal condition Females and Males of Reproductive Potential Based on the mechanism of action, the use of prostaglandin-mediated NSAIDs, including naproxen, may delay or prevent rupture of ovarian follicles, which has been associated with reversible infertility in some women. Published animal studies have shown that administration of prostaglandin synthesis inhibitors has the potential to disrupt prostaglandin- mediated follicular rupture required for ovulation. Small studies in women treated with NSAIDs have also shown a reversible delay in ovulation Consider withdrawal of NSAIDs, including naproxen tablets, in women who have difficulties conceiving or who are undergoing investigation of infertility. Pediatric Use Safety and effectiveness in pediatric patients below the age of 2 years have not been established. Pediatric dosing recommendations for juvenile arthritis are based on well-controlled studies (see DOSAGE AND ADMINISTRATION ). There are no adequate effectiveness or dose-response data for other pediatric conditions, but the experience in juvenile arthritis and other use experience have established that single doses of 2.5 to 5 mg/kg (as naproxen suspension, see DOSAGE AND ADMINISTRATION ), with total daily dose not exceeding 15 mg/kg/day, are well tolerated in pediatric patients over 2 years of age. Safety and effectiveness in pediatric patients below the age of 2 years have not been established. Geriatric Use Elderly patients, compared to younger patients, are at greater risk for NSAID-associated serious cardiovascular, gastrointestinal, and/or renal adverse reactions. If the anticipated benefit for the elderly patient outweighs these potential risks, start dosing at the low end of the dosing range, and monitor patients for adverse effects (see WARNINGS; Cardiovascular Thrombotic Events, Gastrointestinal Bleeding, Ulceration, and Perforation, Hepatotoxicity , Renal Toxicity and Hyperkalemia, PRECAUTIONS; Laboratory Monitoring) . Studies indicate that although total plasma concentration of naproxen is unchanged, the unbound plasma fraction of naproxen is increased in the elderly. Caution is advised when high doses are required and some adjustment of dosage may be required in elderly patients. As with other drugs used in the elderly, it is prudent to use the lowest effective dose. Experience indicates that geriatric patients may be particularly sensitive to certain adverse effects of nonsteroidal anti-inflammatory drugs. Elderly or debilitated patients seem to tolerate peptic ulceration or bleeding less well when these events do occur. Most spontaneous reports of fatal GI events are in the geriatric population (see WARNINGS; Gastrointestinal Bleeding, Ulceration, and Perforation ). Naproxen is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. Geriatric patients may be at a greater risk for the development of a form of renal toxicity precipitated by reduced prostaglandin formation during administration of nonsteroidal anti-inflammatory drugs (see WARNINGS : Renal Toxicity and Hyperkalemia ).