From the FDA Drug Label
DOSAGE AND ADMINISTRATION ... For treatment of pain or primary dysmenorrhea the recommended dosage is 50 mg three times a day ... For the relief of osteoarthritis, the recommended dosage is 100-150 mg/day in divided doses, 50 mg twice a day or three times a day ... For the relief of rheumatoid arthritis, the recommended dosage is 150-200 mg/day in divided doses, 50 mg three times a day or four times a day. The recommended dosing for diclofenac is:
- Pain or primary dysmenorrhea: 50 mg three times a day
- Osteoarthritis: 100-150 mg/day in divided doses, 50 mg twice a day or three times a day
- Rheumatoid arthritis: 150-200 mg/day in divided doses, 50 mg three times a day or four times a day 1
From the Research
The recommended dosing for diclofenac is 100-150 mg per day for osteoarthritis and ankylosing spondylitis, and 150-200 mg per day for rheumatoid arthritis, as evidenced by the most recent and highest quality study 2.
Diclofenac Dosing Considerations
When considering diclofenac dosing, it's essential to take into account the specific formulation and indication.
- For oral immediate-release tablets, the typical adult dose is 50 mg 2-3 times daily or 75 mg twice daily, with a maximum daily dose of 150 mg.
- For extended-release formulations, dosing is usually 100 mg once daily.
- Topical diclofenac gel (1%) is applied 4 times daily to affected joints, using 2-4 grams per application.
- Diclofenac patches (1.3%) are applied twice daily.
- Injectable diclofenac is dosed at 75 mg once or twice daily, administered as a deep intramuscular injection.
Important Considerations
Dosing should be reduced in elderly patients and those with renal impairment.
- Treatment duration should be limited to the shortest period necessary to control symptoms, as NSAIDs increase cardiovascular and gastrointestinal risks with prolonged use.
- Diclofenac works by inhibiting cyclooxygenase enzymes (COX-1 and COX-2), reducing prostaglandin synthesis and thereby decreasing inflammation, pain, and fever.
- Taking oral formulations with food and using gastroprotective agents like proton pump inhibitors may help reduce gastrointestinal side effects, as supported by studies such as 3.
Key Points
- The most recent and highest quality study 2 supports the use of diclofenac as a first-line treatment option for knee and hand OA, especially for older patients and those who have comorbid conditions and/or risk factors for various systemic adverse events.
- Other studies, such as 4 and 5, also provide evidence for the efficacy and safety of diclofenac in the treatment of osteoarthritis and rheumatoid arthritis.
- However, the study by 2 is the most recent and highest quality, and its findings should be prioritized when making treatment decisions.