Diclofenac

Diclofenac primarily exerts its therapeutic effects by inhibiting cyclooxygenase (COX-1 and COX-2) enzymes, which are responsible for the synthesis of prostaglandins. This inhibition leads to reduced production of inflammatory mediators, thereby decreasing pain, inflammation, and fever. It also affects the lipoxygenase pathway to a lesser extent.

Adult

Oral: 50-100 mg/day in 2-3 divided doses for immediate release; 75-150 mg/day in 1-2 divided doses for sustained release. IM: 75 mg once daily, or 75 mg twice daily in severe cases for not more than 2 days. IV: 75 mg over 30-120 minutes, repeated after 4-6 hours if needed, max 150 mg/day (typically for hospital use).

Pediatric

For Juvenile Idiopathic Arthritis (JIA): Oral 1-3 mg/kg/day in 2-3 divided doses (typically for children >1 year, with a maximum dose of 150 mg/day).

Renal adjustment

Use with caution in mild to moderate renal impairment. Avoid in severe renal impairment (eGFR < 30 mL/min/1.73m²).

Hepatic adjustment

Use with caution in mild to moderate hepatic impairment. Avoid in severe hepatic impairment.

Geriatric

Start with the lowest effective dose due to increased risk of adverse effects, particularly GI bleeding and renal impairment. Monitor renal function and GI symptoms closely.

Max dose

150 mg/day (oral, parenteral, or rectal combined).

• Hypersensitivity to diclofenac or other NSAIDs
• Active gastrointestinal bleeding or peptic ulceration
• History of asthma, urticaria, or allergic reactions precipitated by aspirin or other NSAIDs
• Severe heart failure (NYHA Class III-IV)
• Severe renal impairment (eGFR < 30 mL/min/1.73m²)
• Severe hepatic impairment
• Peri-operative pain in the setting of coronary artery bypass graft (CABG) surgery
• Third trimester of pregnancy
• Established ischemic heart disease, peripheral arterial disease, cerebrovascular disease, or uncontrolled hypertension (use with caution, if at all)
• Not recommended for children
• Not recommended for nursing mothers
• Not recommended for pregnant women