Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) of the propionic acid class (the same class as ibuprofen) that relieves pain, fever, swelling, and stiffness. It is a nonselective COX inhibitor, usually sold as the sodium salt. It is available in both an immediate release and extended release formulation. Naproxen is generally safe to use in breastfeeding mothers.

Molecular Structure

Class of Drug


Mechanism of Action

Inhibits cyclooxygenase, resulting in inhibition of synthesis of prostaglandins and other inflammatory mediators.

Indications / Dosage / Route

Routes of Administration: Oral only.

Condition: Rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, dysmenorrhea, tendinitis, bursitis

Dose: Adults: 250-500 mg b.i.d

Dose: Delayed-release tablets: 375-500 mg b.i.d.

Dose: Naproxen sodium: 275-550 mg b.i.d.

Dose: Controlled release tablets: Adults: 750 or 1000 mg/d.

Condition: Acute gout

Dose: Adults: Initial: 750 mg. Maintenance: 250 mg q8h.

Dose: Controlled-release tablets: Adults: 1000-1500 mg once daily.

Dose: Naproxen sodium: Adults: Initial: 825 mg. Maintenance: 275 mg q8h.

Condition: Juvenile rheumatoid arthritis

Dose: 10 mg/kg/d.

Adjustment of Dosage

Kidney disease: None.

Liver disease: None.

Elderly: May be necessary to reduce dose for patients >65 years.

Pediatric: Safety and efficacy have not been established in children <2 years.

Food and Drug Interactions

Food: Take with food or large quantities of water or milk.

Pregnancy: Category B. Category D in third trimester or near delivery.

Lactation: No data available. Best to avoid.

Contraindications: Hypersensitivity and cross-sensitivity with other NSAIDs and aspirin.

Warnings / Precautions

> Use with caution in patients with history of GI bleeding, decreased renal function, rhinitis, urticaria, hay fever, nasal polyps, asthma.

> Administer this drug with caution in patients with infections or other diseases as the drug may mask symptoms of the disease, eg, fever, inflammation.

> NSAIDs may cause severe allergic reactions including urticaria and vasomotor collapse. Cross-reactivity may occur in patients allergic to aspirin.

Clinically Important Drug Interactions

> Drags that increase elfects/toxicity of NSAIDs: alcohol, insulin, cimetidine.

> Drags that decrease elfects/toxicity of NSAIDs: barbiturates, corticosteroids, antacids.

> NSAIDs increase elfects/toxicity of oral anticoagulants, cyclosporine, lithium, methotrexate, sulfonamides, streptokinase, valproic acid, oral hypoglycemics.

> NSAIDs decrease elfects/toxicity of β blockers, calcium channel blockers, loop diuretics, probenecid, sulfinpyrazone.

Adverse Reactions

> Common: nausea, indigestion, dizziness, fatigue.

> Serious: GI bleeding (peptic ulcer, diverticular NSAID colitis), acute renal failure, bronchospasm, Stevens-Johnson syndrome, renal or hepatic toxicity, GI perforation.

Parameters to Monitor

> CBC, liver enzymes, stool hemoccult, serum BUN and creatinine

> Efficacy of treatment: pain reduction, decreased temperature, improved mobility. Assess pain reduction 1 or 2 hours after taking drug.

> Rhinitis, asthma, urticaria before beginning treatment. Such patients are at increased risk of developing hypersensitivity reaction to NSAID.

> Blood glucose of diabetic patients taking oral hypoglycemic drugs. An NSAID may potentiate the hypoglycemic effect of oral hypoglycemic drugs.

> Signs and symptoms of auditory toxicity, in particular tinnitus in elderly patients. Stop drug to avoid irreversible hearing loss. Restart at 50% of previous dose after reversal occurs.

> Symptoms of iron deficiency anemia, particularly in patients on long-term, high-dose drug. Perform hematocrit and guaiac tests periodically.

> Signs and symptoms of renal toxicity.

> Signs and symptoms of hepatotoxicity.

> Symptoms of GI toxicity: occult blood loss, hematochezia, melena, abdominal pain.

> Efficacy in treating rheumatoid arthritis. Increase dose if drug is not effective within 7 days. If maximum dose is not effective, change to another NSAID. If a second- or third-line drug is required, the NSAID should not be stopped.

Advice to Patient

> Avoid use of alcohol.

> Notify physician if your stool turns dark, if you develop abdominal pain, or if you vomit blood or dark material.

> Notify dentist or treating physician prior to surgery if taking this medication.

> Avoid taking OTC products that contain aspirin or other NSAIDs, eg, Alka-Seltzer.

> Take drug with full glass of water and sit up for 15-30 minutes to avoid lodging of tablet in esophagus.

> If pain occurs with physical activity, take drug 30 minutes before physical therapy or other planned exercise.

Further Useful Info

> Some rheumatologists consider aspirin to be the first-line drug for treatment of rheumatoid arthritis. Patient should be given 14-day trial at dose of 3.2 g/d; if ineffective, another drug should be used.

> It is recommended that misoprostol should be given prophylactically for the following patients requiring long-term treatment with an NSAID: those >60 years of age, those with past history of peptic ulcer disease, those concurrently receiving anticoagulants or corticosteroids. Misoprostol has also been shown to reduce the incidence of NSAID-induced ulcers in younger patients.

> Concomitant acid-blocking agents (H2 blockers, proton pump inhibitor) may reduce the incidence of duodenal ulcer but not gastric ulcer in patients on chronic NSAID therapy. They may also reduce NSAID induced GI symptoms.

> Treat Helicobacter plyori if present in patients developing active ulcer on NSAID therapy; use proton pump inhibitor plus two additional antibiotics.

> Newer COX-2 inhibitors are potential alternatives for patients requiring chronic NSAID therapy.

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