Naproxen

Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) that reduces pain, inflammation, and fever by blocking the production of prostaglandins — hormone-like chemicals that play key roles in the inflammatory process ^[1][2].

Naproxen works by inhibiting both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes ^[1]. COX-2 is primarily induced at sites of injury and inflammation, where it produces prostaglandins that cause pain, swelling, and fever. COX-1 is constitutively expressed in most tissues and produces prostaglandins that protect the stomach lining, maintain kidney blood flow, and support platelet aggregation.

By blocking COX-2, naproxen reduces the prostaglandins responsible for inflammation and pain signaling ^[2]. However, because it also blocks COX-1, it reduces the protective prostaglandins in the stomach, which explains the risk of GI ulceration and bleeding that is common to all traditional NSAIDs ^[3].

Notably, naproxen has a relatively balanced inhibition of COX-1 and COX-2, and its antiplatelet effect (via sustained COX-1 inhibition in platelets) may contribute to its relatively favorable cardiovascular safety profile compared to other NSAIDs. The PRECISION trial and multiple meta-analyses suggest naproxen carries the lowest cardiovascular risk among commonly used NSAIDs ^[4][5].

When starting naproxen for acute pain, you may notice relief within 30-60 minutes of the first dose, with the peak effect at 2-4 hours ^[1]. For chronic inflammatory conditions like rheumatoid arthritis, full anti-inflammatory benefit may take 1-2 weeks of regular dosing.

The most common side effects are GI-related: heartburn, nausea, and stomach discomfort affect about 10-15% of patients. Taking naproxen with food or milk and using the lowest effective dose for the shortest duration reduces GI risk ^[1].

Your doctor may prescribe a proton pump inhibitor (like omeprazole) alongside naproxen if you are at increased risk for GI bleeding (age >65, history of ulcers, concurrent anticoagulant use) ^[3].

Avoid taking naproxen within 2 hours of low-dose aspirin if you take aspirin for heart protection, as naproxen can interfere with aspirin's cardioprotective effect when taken first ^[6]. Take aspirin first, then wait at least 2 hours before taking naproxen.

Food: Taking naproxen with food or milk reduces GI side effects and is generally recommended ^[1]. Food delays absorption slightly but does not reduce the total amount absorbed. For acute pain when rapid onset is desired, taking naproxen on an empty stomach with a full glass of water provides faster relief.

Alcohol: Alcohol should be limited or avoided during naproxen therapy ^[1]. Both alcohol and NSAIDs independently damage the gastric mucosa, and their combination significantly increases the risk of GI bleeding. The FDA recommends that patients who consume 3 or more alcoholic drinks daily consult their doctor before using any NSAID ^[3].

Sodium: Naproxen can cause fluid retention. Patients with heart failure or hypertension should be aware of sodium intake during treatment ^[1].

Grapefruit: No significant interaction with naproxen, as it is metabolized primarily by CYP2C9, not CYP3A4 ^[2].

OTC Pain Relief (Aleve): 220 mg naproxen sodium every 8-12 hours; maximum 660 mg/day (3 tablets) ^[1]. May take an initial loading dose of 440 mg (2 tablets) for the first dose.

Prescription — Pain/Inflammation: 250-500 mg twice daily. Maximum 1,250 mg/day for the first dose, then 1,000 mg/day thereafter ^[1].

Rheumatoid Arthritis / Osteoarthritis: 250-500 mg twice daily. Naprosyn: 250-500 mg BID. Naprelan (controlled-release): 750-1,000 mg once daily ^[1].

Acute Gout: Initial dose of 750 mg, then 250 mg every 8 hours until the attack subsides ^[1].

Dysmenorrhea: Initial dose of 500 mg, then 250 mg every 6-8 hours as needed ^[1].

Pediatric (age 2+): 5-7 mg/kg per dose every 8-12 hours ^[1].

Key Principle: Use the lowest effective dose for the shortest duration consistent with individual treatment goals ^[1].

Note: Naproxen sodium 220 mg (OTC) = naproxen base 200 mg. The sodium salt formulation is absorbed slightly faster.

Naproxen is available both over-the-counter (OTC) and by prescription, making it one of the most accessible NSAIDs. OTC Aleve (220 mg naproxen sodium) costs approximately $8-15 for 100 tablets ^[6].

Cost-saving strategies: - OTC is often cheapest: Aleve and store-brand naproxen sodium are widely available without a prescription. A 100-count bottle of generic naproxen sodium 220 mg costs $5-10 at most retailers - Prescription generic: For higher doses (375-500 mg), generic naproxen tablets cost approximately $8-15 for a 30-day supply - $4 generic lists: Prescription naproxen is included on many pharmacy discount programs - Store brands: Walmart, Costco, and Kirkland naproxen sodium are significantly cheaper than Aleve with identical active ingredients - Avoid Naprelan: The controlled-release formulation is more expensive with no proven efficacy advantage over BID immediate-release dosing - GoodRx coupons: Can reduce prescription naproxen costs to $4-8 for a 30-day supply

Pregnancy: Naproxen is contraindicated after 30 weeks of gestation (third trimester) due to the risk of premature closure of the fetal ductus arteriosus, which can cause pulmonary hypertension in the newborn ^[1]. In 2020, the FDA strengthened this warning to include all NSAIDs starting at approximately 20 weeks gestation, due to the risk of oligohydramnios (low amniotic fluid) and fetal renal dysfunction ^[7]. Before 20 weeks, use only if clearly needed and at the lowest dose for the shortest duration.

Breastfeeding: Naproxen is excreted in breast milk in small amounts. The long half-life means drug accumulates compared to shorter-acting NSAIDs. The AAP considers naproxen compatible with breastfeeding, but some experts prefer ibuprofen (shorter half-life, more data) as the NSAID of choice during breastfeeding ^[8]. If naproxen is used, monitor the infant for GI effects.

Fertility: NSAIDs may impair female fertility by inhibiting ovulation. This effect is reversible upon discontinuation ^[1].

Generic naproxen has been available since the 1990s and is the standard formulation dispensed at pharmacies. Brand-name Naprosyn is rarely stocked.

The OTC market is dominated by Aleve (Bayer), which remains a well-known brand, but store-brand and generic naproxen sodium OTC products are therapeutically identical at a fraction of the cost. Look for "naproxen sodium 220 mg" on the label — the generic is exactly the same product.

For prescription strengths, generic naproxen tablets (250 mg, 375 mg, 500 mg) and enteric-coated formulations are widely available from multiple manufacturers, all FDA "AB" rated as equivalent.

The controlled-release formulation (originally Naprelan) is also available generically but offers no significant clinical advantage over twice-daily immediate-release naproxen.