Maximum Recommended Daily Dose of Diclofenac for Adults
The maximum recommended daily dose of diclofenac for adults is 150 mg per day, administered in divided doses. 1, 2, 3
Dosage Guidelines by Route of Administration
Oral Administration
- For osteoarthritis: 100-150 mg/day in divided doses (50 mg twice or three times daily) 1
- For rheumatoid arthritis: 150-200 mg/day in divided doses (50 mg three or four times daily) 1
- For pain or primary dysmenorrhea: 50 mg three times daily (150 mg total) 1
- For over-the-counter use: Maximum 75 mg/day (initial dose of two 12.5 mg tablets followed by one or two tablets every 4-6 hours) 4
Parenteral Administration
- Intravenous: Maximum 150 mg/day, administered as 75 mg every 12 hours 2
- Intramuscular: Maximum 150 mg/day, typically as 75 mg doses with minimum 12-hour intervals between doses 2, 3
Clinical Considerations
Safety Profile
- Higher doses are associated with increased risk of gastrointestinal and renal adverse effects 5
- Use the lowest effective dose for the shortest duration consistent with individual treatment goals 1
- Diclofenac has a relatively short elimination half-life in plasma (1.5 hours) but persists longer in synovial fluid 6
Special Populations
- Caution is needed in patients with:
Formulation Differences
- Different formulations of diclofenac (sodium enteric-coated tablets, sodium extended-release tablets, potassium immediate-release tablets) are not necessarily bioequivalent even at the same milligram strength 1
- Fast-acting formulations (dispersible products, solutions, and softgel formulations) may have better efficacy for acute pain 7
Monitoring Recommendations
- Monitor renal function with serum creatinine and electrolytes if treatment extends beyond 3-5 days 3
- Watch for signs of gastrointestinal adverse effects (abdominal pain, nausea, vomiting) 3
- Discontinue diclofenac if signs of renal deterioration or significant gastrointestinal symptoms occur 3
Drug Interactions
- Significant interactions have been demonstrated with:
- Aspirin (acetylsalicylic acid)
- Lithium
- Digoxin
- Methotrexate
- Cyclosporin
- Cholestyramine and colestipol 8
- NSAIDs taken with prescribed anticoagulants may significantly increase bleeding risk 5
Remember that diclofenac should be used at the lowest effective dose for the shortest duration possible to minimize adverse effects while maintaining therapeutic benefit.