Naproxen

# Naproxen ## Overview - **Classification**: Nonsteroidal Anti-inflammatory Drug (NSAID), Propionic Acid Derivative. - **Mechanism**: Reversibly inhibits cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes, which decreases prostaglandin synthesis, leading to anti-inflammatory, analgesic, and antipyretic effects. ## Primary Indications 1. **Pain Management**: Mild to moderate acute pain (e.g., dental, musculoskeletal). 2. **Inflammation**: Treatment of acute and chronic inflammatory diseases (e.g., rheumatoid arthritis, osteoarthritis). 3. **Menstrual Pain**: Primary dysmenorrhea (Naproxen Sodium is often used). ## Adult Dosing ### Standard Dosing **Acute Pain and Dysmenorrhea (Naproxen Sodium)** - **Dose**: **550 mg** initially, then **275 mg** or **550 mg** - **Frequency**: Every 6-8 hours as needed. - **Route**: Oral - **Maximum Daily Dose**: **1375 mg** (first day), then **1100 mg** daily. **Chronic Inflammatory Conditions (Naproxen)** - **Dose**: **250 mg**, **375 mg**, or **500 mg** - **Frequency**: Twice daily (BID). - **Route**: Oral - **Maximum Daily Dose**: **1500 mg** for short periods only; standard max is **1000 mg** daily. ### Dose Adjustments - **Renal Impairment**: Avoid use if CrCl **<30 mL/min**. Lower doses are recommended for moderate impairment. - **Hepatic Impairment**: Use the **lowest effective dose**. Monitor liver function closely, consider dose reduction or avoidance. - **Elderly Patients**: Start with the **lowest effective dose** due to increased risk of GI toxicity and impaired renal function. ## Pediatric Dosing Naproxen is approved for use in children for juvenile idiopathic arthritis (JIA) and pain. **Use of immediate-release suspension/tablets is preferred.** ### Neonates (0-28 days) - **Dose**: **Not recommended**. - **Special Notes**: High risk of adverse renal and GI effects in this age group. ### Infants (1-12 months) - **Dose**: **Not recommended** or studied extensively. ### Children (2-12 years) **Juvenile Idiopathic Arthritis (JIA)** - **Dose**: **5–7 mg/kg/dose** - **Frequency**: Twice daily (BID), every 12 hours. - **Maximum**: Do not exceed **1000 mg** daily. - **Formulation**: Oral suspension (125 mg/5 mL) is available. ### Adolescents (13-18 years) - **Dose**: Generally follow **adult dosing** guidelines. - **Maximum**: **1000 mg** daily (standard chronic dose). ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity/allergy to naproxen or other NSAIDs (cross-reactivity with aspirin). - **Absolute**: Peri-operative pain in the setting of CABG surgery. - **Absolute**: History of severe GI bleeding or active peptic ulcer disease. - **Absolute**: Late third trimester of pregnancy (risk of premature ductus arteriosus closure). ### Common Adverse Effects - **Very Common (>10%)**: Dyspepsia, Headache. - **Common (1-10%)**: Nausea, Abdominal pain, Edema, Dizziness, Constipation. - **Serious but Rare**: GI ulceration/bleeding, Acute renal failure, Myocardial infarction, Severe dermatologic reactions (SJS/TEN). ### Key Drug Interactions - **Anticoagulants (Warfarin)**: Increased risk of serious bleeding. Monitor INR closely; consider alternatives. - **ACE Inhibitors/ARBs**: Increased risk of renal dysfunction and attenuated antihypertensive effect. - **Diuretics (Furosemide)**: Reduced diuretic and natriuretic effects. - **Lithium**: Decreased renal clearance of lithium, leading to increased toxicity. Monitor lithium levels. - **SSRI/SNRI/Antiplatelets**: Increased risk of GI bleeding. Avoid combination or use PPI prophylaxis. ## Monitoring & Follow-up - **Before Treatment**: Baseline CBC (if long-term), Renal function (SCr, BUN), Liver function (AST/ALT). - **During Treatment**: Monitor for signs of GI bleeding. Check blood pressure regularly. - **Long-term Monitoring**: Renal function and CBC every 6–12 months, especially in the elderly or those taking high doses. - **Clinical Signs**: Watch for unexplained weight gain or peripheral edema (heart failure risk). ## Clinical Pearls - 💡 **Tip 1**: Take with food or milk to minimize GI irritation. - 💡 **Tip 2**: Naproxen has a longer half-life (12-17 hours) than ibuprofen, allowing for twice-daily dosing. - 💡 **Tip 3**: Naproxen is sometimes considered to have a **lower cardiovascular risk** compared to high-dose ibuprofen or selective COX-2 inhibitors. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.