From the Guidelines
Diclofenac should be prescribed at a dose of 50 mg taken 2-3 times daily or 75 mg twice daily for most inflammatory conditions, with a maximum daily dose of 150 mg, as this dosing regimen has been shown to be effective in reducing pain and inflammation while minimizing gastrointestinal risks 1.
Key Considerations
- The medication should be taken with food or milk to reduce gastrointestinal irritation.
- Treatment duration should be limited to the shortest period necessary to control symptoms due to potential side effects, particularly cardiovascular and gastrointestinal risks.
- Patients with heart disease, hypertension, kidney problems, or a history of stomach ulcers should use diclofenac cautiously and may require lower doses or alternative medications.
Dosing Regimens
- For acute pain, the dosing may start at 50 mg three times daily and can be reduced to twice daily as symptoms improve.
- Extended-release formulations are available as 75 mg or 100 mg tablets taken once or twice daily.
- Topical diclofenac gel (1%) can be applied to affected areas 3-4 times daily for localized pain.
Mechanism of Action
- Diclofenac works by inhibiting cyclooxygenase enzymes (COX-1 and COX-2), which reduces prostaglandin production and decreases inflammation, pain, and fever.
Safety Considerations
- The use of NSAIDs, including diclofenac, has been associated with an increased risk of gastrointestinal complications, particularly in patients with a history of stomach ulcers or bleeding 1.
- COX-2 selective agents or the addition of a gastroprotective agent to a conventional NSAID may be considered in patients with an increased risk of gastrointestinal complications 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Carefully consider the potential benefits and risks of diclofenac potassium tablets and other treatment options before deciding to use diclofenac potassium tablets. Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS: Gastrointestinal Bleathing, Ulceration, and Perforation) After observing the response to initial therapy with diclofenac potassium tablets, the dose and frequency should be adjusted to suit an individual patient's needs. For treatment of pain or primary dysmenorrhea the recommended dosage is 50 mg three times a day With experience, physicians may find that in some patients an initial dose of 100 mg of diclofenac potassium tablets, followed by 50 mg doses, will provide better relief. 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 dose and frequency of Diclofenac are as follows:
- 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 It is also recommended to use the lowest effective dose for the shortest duration consistent with individual patient treatment goals 2.
From the Research
Diclofenac Dosage and Frequency
- The recommended dose of Diclofenac potassium is 12.5mg, with a flexible daily dosing regimen of an initial dose of two tablets (2 x 12.5mg) followed by one or two tablets up to a maximum daily dose of six tablets (75 mg/day) 3.
- A single dose of diclofenac potassium 12.5mg is the lowest recommended effective dose, and a two-tablet single dose of 25mg is at least as effective as ibuprofen 400mg 3.
- For primary dysmenorrhea, the daily recommended dose of diclofenac potassium is 150 mg, administered at set intervals across the first 24 h of menstruation, in three 50 mg doses across the day and evening 4.
Comparison with Other NSAIDs
- Diclofenac potassium has been compared to other NSAIDs, such as ibuprofen, naproxen, and acetaminophen, in terms of efficacy and safety for primary dysmenorrhea 5, 6, 7.
- A network meta-analysis found that diclofenac was one of the most effective NSAIDs for primary dysmenorrhea, with an odds ratio of 11.82 (95% CI 2.66-52.48) compared to placebo 6.
- Another study found that a single dose of naproxen sodium (440mg) was more effective than acetaminophen (1000mg) for primary dysmenorrhea, with a significant difference in total pain relief over 12 hours (TOTPAR0-12) 7.
Safety and Tolerability
- The incidence of adverse events in patients taking diclofenac potassium is similar to that of ibuprofen and placebo 3.
- A safety study conducted to compare diclofenac potassium with ibuprofen for up to 3 months in patients with osteoarthritis of the knee found no differences in the pattern of adverse events 3.
- A network meta-analysis found that there was no significant difference in safety between diclofenac and other NSAIDs, including ibuprofen, naproxen, and acetaminophen 6.