📋 Clinical Overview

Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) of the propionic acid class, widely used in India for its analgesic, anti-inflammatory, and antipyretic properties. It is a non-selective inhibitor of cyclooxygenase (COX) enzymes, with a longer duration of action compared to other NSAIDs like ibuprofen, making it suitable for twice-daily dosing in chronic conditions like osteoarthritis and rheumatoid arthritis.

💊 Dosage & Administration

Adult: For pain/dysmenorrhea: Initial 500mg, then 250mg every 6-8 hours as needed. Max initial daily dose 1250mg. For arthritis: 500mg to 1000mg daily in two divided doses (e.g., 500mg twice daily).

Note: Take with food or a full glass of milk/water to minimize gastric upset. Swallow tablet whole; do not crush or chew. For delayed-release/enteric-coated formulations, do not break the tablet. Maintain adequate fluid intake.

⚠️ Contraindications

Known hypersensitivity (e.g., asthma, urticaria, allergic-type reactions) to naproxen, aspirin, or other NSAIDs.
History of aspirin-induced asthma or nasal polyps.
Active peptic ulcer disease or GI bleeding.
Severe heart failure (NYHA Class IV).
Third trimester of pregnancy.
Severe renal impairment (CrCl <30 mL/min).
Coronary artery bypass graft (CABG) surgery-associated pain.

🔬 Mechanism of Action

Naproxen exerts its therapeutic effects by non-selectively inhibiting both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) isoenzymes. This inhibition blocks the conversion of arachidonic acid to prostaglandin G2 and subsequently to prostaglandin H2, the precursor for various prostaglandins (PGs) and thromboxanes.

🤕 Side Effects

Dyspepsia (indigestion, heartburn)
Nausea
Abdominal pain
Headache
Dizziness
Skin rash/itching
Edema (fluid retention)
Tinnitus (ringing in ears)

🤰 Special Populations

Pregnancy: Category C in first and second trimester (use only if potential benefit justifies risk). Category D in third trimester (contraindicated due to risk of premature closure of ductus arteriosus, oligohydramnios, and prolonged labor).

Driving: May cause dizziness, drowsiness, vertigo, or blurred vision. Patients should not drive or operate machinery if affected.

🔄 Drug Interactions

Warfarin/Acenocoumarol	Increased risk of bleeding due to protein binding displacement and antiplatelet effect.	Major
Aspirin (low-dose)	Competitive protein binding may reduce naproxen levels; increased GI toxicity.	Moderate
Lithium	Decreased renal clearance of lithium, leading to toxicity.	Major
Methotrexate	Decreased renal clearance of methotrexate, increasing risk of bone marrow suppression.	Major
ACE Inhibitors (e.g., Enalapril, Ramipril)	Reduced antihypertensive effect; increased risk of renal impairment.	Moderate
Diuretics (e.g., Furosemide)	Reduced diuretic and antihypertensive efficacy; risk of renal impairment.	Moderate
SSRIs (e.g., Sertraline, Escitalopram)	Increased risk of upper GI bleeding.	Moderate
Corticosteroids (e.g., Prednisolone)	Synergistic increase in risk of GI ulceration.	Major

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