Maximum Daily Dosing of Diclofenac
The maximum recommended daily dose of diclofenac is 200 mg per day for rheumatoid arthritis, and 150 mg per day for osteoarthritis, as indicated in the FDA drug label. 1
Specific Dosing Recommendations by Indication
Rheumatoid Arthritis
- Recommended dosage: 150-200 mg/day in divided doses
- Typical regimen: 50 mg three or four times daily 1
Osteoarthritis
- Recommended dosage: 100-150 mg/day in divided doses
- Typical regimen: 50 mg two or three times daily 1
Pain/Primary Dysmenorrhea
- Recommended dosage: 50 mg three times daily
- For some patients, an initial dose of 100 mg followed by 50 mg doses may provide better relief 1
Important Dosing Principles
- Use the lowest effective dose for the shortest duration consistent with treatment goals to minimize adverse effects 1
- The risk of gastrointestinal adverse events is dose-dependent:
- 75 mg/day: odds ratio of 2.2
- 75-150 mg/day: odds ratio of 3.2
150 mg/day: odds ratio of 12.2 2
Special Considerations
Administration
- Administer in divided doses with meals to improve tolerability 3
- Different formulations of diclofenac (sodium enteric-coated, sodium extended-release, potassium immediate-release) are not necessarily bioequivalent even at the same milligram strength 1
Risk Mitigation
- For patients with increased gastrointestinal risk, consider:
- Using a gastroprotective agent alongside diclofenac
- Using a selective COX-2 inhibitor instead 2
- Monitor patients for:
- GI bleeding (especially elderly or those with history of peptic ulcer)
- Renal function (in patients with pre-existing renal impairment)
- Liver function (with prolonged use)
- Cardiovascular risk (before and during treatment) 2
Over-the-Counter Use
- For OTC preparations (12.5 mg tablets):
- Initial dose: two tablets (25 mg)
- Maximum daily dose: six tablets (75 mg/day)
- Maximum treatment duration: 5 days for pain, 3 days for fever 4
Clinical Pearls
- Despite diclofenac's short plasma half-life (1.5 hours), it persists in synovial fluid, which contributes to its prolonged therapeutic effect 3, 5
- Dosage adjustments may not be required for elderly patients, children, or patients with various disease states such as hepatic disease or rheumatoid arthritis 5
- Significant drug interactions exist with aspirin, lithium, digoxin, methotrexate, cyclosporin, cholestyramine and colestipol 5