What is the recommended dosage of naproxen (Nonsteroidal Anti-Inflammatory Drug) for adults?

Naproxen Dosage for Adults

For most adult indications, naproxen is dosed at 500 mg twice daily, with specific conditions requiring different regimens as outlined below. 1

Standard Dosing by Indication

Chronic Inflammatory Conditions (Rheumatoid Arthritis, Osteoarthritis, Ankylosing Spondylitis)

• Standard dose: 250 mg, 375 mg, or 500 mg twice daily 1
• The morning and evening doses do not need to be equal 1
• For long-term management, doses can be adjusted based on clinical response 1
• Higher doses (up to 1500 mg/day) may be used for limited periods up to 6 months when greater anti-inflammatory activity is required, though this increases risk 1

Acute Pain Conditions (Primary Dysmenorrhea, Acute Tendonitis, Bursitis)

• Initial dose: 500 mg, followed by 500 mg every 12 hours OR 250 mg every 6-8 hours 1
• Maximum initial daily dose: 1250 mg 1
• Maximum maintenance daily dose: 1000 mg 1
• Naproxen sodium is preferred for acute pain due to more rapid absorption 1

Acute Gout

• Initial dose: 750 mg, followed by 250 mg every 8 hours until the attack subsides 1

Naproxen vs Naproxen Sodium Equivalency

Naproxen sodium 550 mg is equivalent to naproxen 500 mg 2, 3. The sodium salt formulation provides faster absorption and onset of pain relief (within 1 hour) 1, making it preferable for acute pain management 1.

Common dosing conversions from guidelines:

• Naproxen sodium 440 mg ≈ Naproxen 400 mg 2
• Naproxen sodium 220 mg ≈ Naproxen 200 mg 2

Pharmacokinetic Considerations

Naproxen demonstrates linear pharmacokinetics across the OTC dose range, meaning plasma levels increase proportionately with dose 3. This allows for predictable dose-response relationships and confirms that higher doses provide greater therapeutic efficacy 3.

Special Population Adjustments

Elderly Patients

• Use the lowest effective dose 1
• Although total plasma concentration remains unchanged, the unbound fraction increases in elderly patients 1
• Dose adjustment may be required when using higher doses 1

Renal Impairment

• Naproxen is NOT recommended for patients with moderate to severe renal impairment (creatinine clearance <30 mL/min) 1
• Use with caution when combining with ACE inhibitors or beta blockers due to additive renal effects 4

Hepatic Impairment

• Lower doses should be considered 1

Critical Safety Considerations

Gastrointestinal Risk

• 10-20% of patients experience dyspepsia or GI discomfort 4
• Risk of GI bleeding is age-dependent: 1 in 2,100 for adults <45 years vs. 1 in 110 for adults >75 years 4
• Combine with PPI or H2 blocker for gastroprotection in high-risk patients 4
• Avoid in patients with history of NSAID-associated upper GI bleeding 4

Cardiovascular Risk

• Avoid in patients with congestive heart failure 4
• Use with caution in hypertension (mean BP increase of 5 mmHg) 4
• NSAIDs cause 3.5 excess cardiac ischemic events per 1,000 persons compared to placebo 4

Drug Interactions

• Avoid combining with anticoagulants (increases GI bleeding risk 3-6 fold and INR by up to 15%) 4
• Risk increases with concurrent antiplatelet agents 4

Monitoring Requirements

• Baseline and every 3 months: blood pressure, BUN, creatinine, liver function tests, CBC, and fecal occult blood 4

Duration of Therapy

If two NSAIDs tried in succession show no efficacy, use another approach to analgesia 4. For sustained-release formulations, once-daily dosing of 1000 mg has been shown equivalent to conventional twice-daily dosing with potentially lower GI side effects 5.

Clinical Pearls

• Pain relief onset begins within 1 hour 1
• Weighted mean time to remedication for naproxen sodium 550 mg is 7.6 hours vs. 2.6 hours for placebo 2
• Variable dosing regimens (allowing patients to self-adjust within a maximum daily dose) can reduce drug consumption by 20-30% while maintaining efficacy 6
• Different formulations (tablets, suspension, delayed-release) are not bioequivalent and should not be interchanged without consideration 1