What is the regular dose of diclofenac (Non-Steroidal Anti-Inflammatory Drug (NSAID)) for an adult patient with no significant renal impairment or other contraindications?

Regular Diclofenac Dosing for Adults

For acute pain or primary dysmenorrhea, the standard dose is diclofenac potassium 50 mg three times daily (total 150 mg/day), while for chronic inflammatory conditions like osteoarthritis the dose is 100-150 mg/day in divided doses, and for rheumatoid arthritis 150-200 mg/day in divided doses. 1

Standard Dosing by Indication

Acute Pain and Primary Dysmenorrhea

• Initial dose: 50 mg three times daily 1
• For more severe acute pain, an initial dose of 100 mg followed by 50 mg doses may provide better relief 1
• Maximum daily dose: 150 mg 2

Osteoarthritis

• Recommended dose: 100-150 mg/day in divided doses 1
• Typical regimen: 50 mg twice daily or three times daily 1

Rheumatoid Arthritis

• Recommended dose: 150-200 mg/day in divided doses 1
• Typical regimen: 50 mg three times daily or four times daily 1

Kidney Stone Pain (Renal Colic)

• Oral: 50 mg three times daily 2
• Intravenous: 75 mg every 12 hours 2
• Maximum daily dose: 150 mg 2

Formulation Considerations

Diclofenac potassium (immediate-release) is preferred over diclofenac sodium (enteric-coated) for acute pain because it provides faster onset of action and superior efficacy. 3

• Diclofenac potassium 50 mg has an NNT (number needed to treat) of 2.1 for at least 50% pain relief, indicating high efficacy 3
• Diclofenac sodium 50 mg has an NNT of 6.6, indicating significantly lower efficacy and should probably not be used in acute pain 3
• Peak plasma concentration occurs 30 minutes after administration of diclofenac potassium 4
• Different formulations (sodium enteric-coated, sodium extended-release, potassium immediate-release) are not bioequivalent even at the same milligram strength 1

Administration Guidelines

• Use the lowest effective dose for the shortest duration to minimize gastrointestinal and cardiovascular risks 1
• Administer with meals to reduce gastrointestinal side effects 1
• After observing initial response, adjust dose and frequency to suit individual patient needs 1

Duration and Monitoring

Short-term Use (Acute Pain)

• For over-the-counter use: maximum 5 days for pain, 3 days for fever 4
• If treatment extends beyond 3-5 days, monitor renal function with serum creatinine and electrolytes 2

Long-term Use (Chronic Conditions)

• Initial treatment should be 2-4 weeks at maximum tolerated dose 5
• Evaluate treatment response at 2-4 weeks 5
• Watch for signs of gastrointestinal adverse effects (abdominal pain, nausea, vomiting) 2

Special Populations and Dose Adjustments

Renal Impairment

• Creatinine clearance <10 mL/min: Consider dose reduction 2
• Avoid in end-stage renal disease or dialysis-dependent patients 2
• Monitor renal function closely if used in any degree of renal impairment 2

Contraindications and Cautions

• Avoid in severe heart failure, liver failure, or history of gastrointestinal bleeding 2
• Discontinue if signs of renal deterioration or significant gastrointestinal symptoms occur 2
• Use caution with concomitant anticoagulants due to increased bleeding risk 2

Clinical Pearls

• For acute pain requiring rapid onset, use diclofenac potassium, not sodium 3
• The 50 mg three times daily regimen (150 mg/day total) represents the standard effective dose for most acute pain conditions 1
• Diclofenac persists in synovial fluid despite short plasma half-life (1.5 hours), contributing to its anti-inflammatory effects 6
• Fast-acting formulations (dispersible, solutions, softgel) have similar efficacy to standard immediate-release tablets 3