Tab Diclofenac

# Tab diclofenac ## Overview - **Classification**: Nonsteroidal Anti-inflammatory Drug (NSAID), phenylacetic acid derivative. - **Mechanism**: Reversibly inhibits cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes, reducing prostaglandin synthesis. This provides anti-inflammatory, analgesic, and antipyretic effects. ## Primary Indications 1. **Osteoarthritis (OA)** - Relief of signs and symptoms. 2. **Rheumatoid Arthritis (RA)** - Relief of signs and symptoms. 3. **Ankylosing Spondylitis** - Relief of signs and symptoms. 4. **Pain** - Mild to moderate acute pain (e.g., dysmenorrhea). ## Adult Dosing ### Standard Dosing **Osteoarthritis** - **Dose**: **50 mg** or **75 mg** - **Frequency**: **50 mg** **BID-TID**; **75 mg** **BID** - **Route**: Oral - **Maximum**: **150 mg/day** **Rheumatoid Arthritis** - **Dose**: **50 mg** - **Frequency**: **3-4 times daily** - **Route**: Oral - **Maximum**: **200 mg/day** **Ankylosing Spondylitis** - **Dose**: **25 mg** - **Frequency**: **4 times daily**, with an additional **25 mg** at bedtime if needed. - **Route**: Oral - **Maximum**: **125 mg/day** **Mild to Moderate Pain/Dysmenorrhea** - **Dose**: **50 mg** - **Frequency**: **3 times daily** initially, then adjust as needed. - **Route**: Oral - **Maximum**: **150 mg/day** ### Dose Adjustments - **Renal Impairment**: Not recommended in advanced renal disease (CrCl < **30 mL/min**). Use lowest effective dose with caution in mild-moderate impairment. - **Hepatic Impairment**: Use with caution. Consider lower doses. Avoid in severe hepatic failure; monitor LFTs. - **Elderly Patients**: Increased risk of adverse effects. Start at lowest effective dose and monitor closely for GI, renal, and CV toxicity. ## Pediatric Dosing *Note: Systemic oral diclofenac is generally **not recommended** for children under 18 years due to limited safety data, except for specific conditions like Juvenile Idiopathic Arthritis (JIA) under specialist supervision.* ### Neonates (0-28 days) - **Dose**: **Not recommended**. - **Special Notes**: High risk of serious renal, GI, and cardiovascular complications. ### Infants (1-12 months) - **Dose**: **Not recommended**. - **Special Notes**: Safety and efficacy not established. ### Children (1-12 years) *For Juvenile Idiopathic Arthritis (JIA) - **ONLY under specialist supervision*** - **Dose**: **0.5-2 mg/kg/day** - **Frequency**: Divided **2-3 times daily** - **Maximum**: **150 mg/day** or **3 mg/kg/day**, whichever is lower. - **Special Notes**: Monitor closely for GI, renal, and hepatic adverse effects. ### Adolescents (13-18 years) *For specific conditions under specialist guidance (e.g., JIA, severe pain not responsive to other NSAIDs).* - **Dose**: Refer to adult dosing guidelines for specific indications. - **Maximum**: **150 mg/day** generally; up to **200 mg/day** for RA. - **Special Notes**: Use lowest effective dose. Monitor for adult-like adverse effects. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to diclofenac, aspirin, or other NSAIDs (asthma, urticaria, allergic reactions). - **Absolute**: History of GI bleeding or perforation related to previous NSAID use. - **Absolute**: Active peptic ulcer, gastrointestinal bleeding, or perforation. - **Absolute**: Severe heart failure (NYHA Class III-IV). - **Absolute**: Severe renal or hepatic impairment. - **Absolute**: Coronary Artery Bypass Graft (CABG) surgery (peri-operative pain). - **Absolute**: Third trimester of pregnancy. ### Common Adverse Effects - **Very Common (>10%)**: Abdominal pain, indigestion, nausea, diarrhea, headache, dizziness. - **Common (1-10%)**: GI ulceration/bleeding, elevated liver enzymes, rash, edema, hypertension. - **Serious but Rare**: GI perforation, thrombotic cardiovascular events (MI, stroke), acute kidney injury, severe skin reactions (SJS, TEN), heart failure exacerbation, anaphylaxis. ### Key Drug Interactions - **Anticoagulants (warfarin, DOACs)**: Increased risk of bleeding. Monitor INR/bleeding closely. - **Antiplatelet agents (aspirin, clopidogrel)**: Increased risk of GI bleeding. Generally avoid concurrent use. - **Corticosteroids**: Increased risk of GI ulceration/bleeding. - **SSRIs/SNRIs**: Increased risk of GI bleeding. - **Lithium**: Increased lithium levels and toxicity. Monitor lithium levels. - **Methotrexate**: Increased methotrexate levels and toxicity. Monitor for toxicity. - **Diuretics (furosemide, HCTZ)**: Reduced diuretic/antihypertensive effects. Increased risk of renal impairment. - **ACE inhibitors/ARBs**: Reduced antihypertensive effects. Increased risk of renal impairment and hyperkalemia. ## Monitoring & Follow-up - **Before Treatment**: Baseline CBC, LFTs, BUN/Creatinine, blood pressure. Assess GI/CV risk factors. - **During Treatment**: Monitor blood pressure regularly. Monitor renal function (BUN/Creatinine) annually or more often in high-risk patients. Monitor LFTs periodically (e.g., first 8 weeks, then PRN). Watch for signs of GI bleeding. - **Clinical Signs**: Watch for signs of GI upset, unusual bleeding/bruising, edema, unexplained weight gain, rash, dark urine, jaundice. ## Clinical Pearls - 💡 **Lowest effective dose**: Always use the lowest effective dose for the shortest duration necessary to minimize adverse effects. - 💡 **Take with food**: To reduce gastrointestinal upset, advise patients to take diclofenac with food or milk. - 💡 **CV/GI risk**: Diclofenac carries **Black Box Warnings** for serious cardiovascular thrombotic events and gastrointestinal bleeding, ulceration, and perforation. - 💡 **Potassium elevation**: Can cause hyperkalemia, especially in patients also on ACEi/ARBs, potassium-sparing diuretics, or with renal impairment. - 💡 **Hepatic monitoring**: Diclofenac can cause significant LFT elevations. Monitor transaminases closely, especially in the first 8 weeks. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.