naproxen: clinical use

Prescribing considerations

• Confirm the exact product because age limits, indications, excipients and administration differ.
• Assess gastrointestinal, renal, cardiovascular and bleeding risks, including concurrent medicines.
• Consider gastroprotection where gastrointestinal risk warrants it.
• Use additional caution in older or dehydrated patients and in asthma, inflammatory bowel disease, hypertension, heart failure, or impaired renal or hepatic function.
• Naproxen can mask fever and inflammation and reversibly inhibit platelet aggregation.

Contraindications and cautions

• Hypersensitivity to naproxen or a previous asthma, rhinitis, urticaria, angioedema or other serious reaction to aspirin or another NSAID.
• Active or recurrent peptic ulceration or gastrointestinal haemorrhage, or previous NSAID-associated gastrointestinal bleeding or perforation.
• Severe renal, hepatic or cardiac failure.
• Last trimester of pregnancy.
• Product-specific excipient contraindications, including relevant hereditary sugar-intolerance disorders for some tablets or oral suspension.

Monitoring

• Consider baseline blood pressure, renal function and full blood count; check liver tests when hepatic impairment is present.
• After initiation or a clinically significant change, consider renal function, blood pressure, full blood count and haemoglobin according to risk.
• During ongoing treatment, periodically reassess benefit, gastrointestinal symptoms, blood pressure, renal function, blood count and liver function where indicated.
• Monitor interacting medicines when relevant, including anticoagulation, lithium and cardiac glycoside concentrations.

Clinical pharmacology

Naproxen is a propionic-acid NSAID that inhibits prostaglandin synthesis. It is well absorbed orally, extensively protein-bound, has a plasma half-life of approximately 12–15 hours and is eliminated mainly in urine as unchanged or conjugated compounds.

Formulation and product differences

• Oral suspension must be shaken and measured accurately; it contains sucrose, sorbitol, sodium and a parahydroxybenzoate preservative.
• Standard tablets are swallowed with water; the selected tablet product contains lactose.
• Gastro-resistant tablets must be swallowed whole and have a narrower, product-specific pharmacy licence.
• Effervescent tablets are dissolved in water and contain a substantial sodium load, plus benzyl alcohol and sorbitol.

Effervescent tablet

Route: Oral

Strengths: 250 mg

Gastro-resistant tablet

Route: Oral

Strengths: 250 mg, 375 mg, 500 mg