Diclofenac is a widely prescribed nonsteroidal anti-inflammatory drug (NSAID) renowned for its efficacy in managing pain, reducing inflammation, and alleviating fever. As a cornerstone in therapeutic regimens for musculoskeletal and arthritic conditions, it operates by inhibiting cyclooxygenase (COX) enzymes, thereby diminishing prostaglandin production. Available in multiple formulations including oral tablets, topical gels, and injectable solutions, it offers flexibility in treatment approaches tailored to patient-specific needs and severity profiles. Its robust pharmacokinetic profile ensures rapid onset and sustained relief, making it a first-line option in both acute and chronic pain management protocols.

Features

• Active Ingredient: Diclofenac sodium or diclofenac potassium
• Drug Class: Nonsteroidal anti-inflammatory drug (NSAID)
• Available Forms: Oral tablets, capsules, topical gel, solution, injectable, suppositories
• Mechanism of Action: Reversible inhibition of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes
• Onset of Action: Approximately 30 minutes for oral forms; variable for topical applications
• Half-Life: 1–2 hours (short, but with prolonged tissue retention)
• Bioavailability: ~50–60% orally; lower for topical formulations
• Excretion: Primarily renal, with biliary involvement

Benefits

• Effectively reduces moderate to severe pain associated with inflammatory conditions
• Decreases swelling, stiffness, and joint tenderness in arthritis patients
• Provides antipyretic properties to manage fever in adults
• Enables improved mobility and functional capacity in chronic musculoskeletal disorders
• Offers formulation versatility for targeted or systemic delivery
• Supports multimodal pain management strategies with complementary analgesics

Common use

Diclofenac is indicated for the treatment of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and acute gouty arthritis. It is also prescribed for management of acute musculoskeletal pain such as sprains, strains, and post-operative pain. Off-label uses include dysmenorrhea, migraine attacks, and renal colic. Topical formulations are commonly applied for localized pain relief in osteoarthritis of superficial joints like knees and hands, minimizing systemic exposure.

Dosage and direction

Dosage varies by indication, formulation, and patient factors. For oral tablets in adults: osteoarthritis—50 mg two to three times daily or 75 mg twice daily; rheumatoid arthritis—50 mg three to four times daily or 75 mg twice daily. Maximum daily dose should not exceed 150 mg. Topical gel: apply 4g to affected area four times daily. Injectables are administered under medical supervision. Always take with food or milk to reduce gastrointestinal irritation. Do not crush, chew, or break extended-release tablets.

Precautions

Use the lowest effective dose for the shortest duration possible. Monitor renal function, especially in elderly patients or those with pre-existing renal impairment. Assess cardiovascular risk prior to and during treatment. Avoid use in patients with hypertension unless adequately controlled. Caution is advised in patients with asthma, dehydration, or history of peptic ulcer disease. Periodic liver function tests are recommended during prolonged therapy. Topical use: avoid application to broken skin, open wounds, or mucous membranes.

Contraindications

Hypersensitivity to diclofenac, aspirin, or other NSAIDs. History of asthma, urticaria, or allergic-type reactions after taking NSAIDs. Peri-operative pain in setting of coronary artery bypass graft (CABG) surgery. Third trimester of pregnancy. Severe renal impairment or active renal disease. Active gastrointestinal bleeding or ulceration. Severe hepatic impairment or active liver disease.

Possible side effect

Common: nausea, dyspepsia, diarrhea, abdominal pain, headache, dizziness. Serious: gastrointestinal bleeding, perforation, or ulceration; hepatotoxicity; hypertension; heart failure; renal papillary necrosis; anaphylactic reactions; Stevens-Johnson syndrome; aseptic meningitis. Topical: dry skin, pruritus, erythema, contact dermatitis.

Drug interaction

Significant interactions include: increased risk of bleeding with anticoagulants (e.g., warfarin); reduced antihypertensive effect with ACE inhibitors; increased lithium and digoxin levels; enhanced nephrotoxicity with cyclosporine; increased methotrexate toxicity. Concurrent use with other NSAIDs or corticosteroids increases gastrointestinal risk. Aspirin may decrease diclofenac concentration.

Missed dose

If a dose is missed, take it as soon as remembered unless it is nearly time for the next dose. Do not double the dose to catch up. Resume regular dosing schedule. For topical formulations, apply the next dose at the usual time; do not apply extra gel.

Overdose

Symptoms may include nausea, vomiting, epigastric pain, gastrointestinal bleeding, drowsiness, tinnitus, seizures, acute renal failure. Respiratory depression and coma may occur in severe cases. No specific antidote exists. Management is supportive: gastric lavage or activated charcoal if presented early. Hemodialysis is not effective due to high protein binding. Monitor and treat electrolyte imbalances, acidosis, and organ dysfunction.

Storage

Store at room temperature (20–25°C). Protect from light and moisture. Keep oral forms in original container; tightly close after use. Topical gels should not be exposed to high temperatures. Keep all medications out of reach of children and pets. Do not use beyond the expiration date.

Disclaimer

This information is for educational purposes and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting, changing, or stopping any medication. Individual response to therapy may vary. Not all uses, precautions, or interactions are listed here.

Reviews

Clinical studies and meta-analyses consistently demonstrate diclofenac’s superiority over placebo and non-inferiority to other NSAIDs in pain and inflammation reduction. Systematic reviews highlight its efficacy in osteoarthritis and acute pain, though note gastrointestinal and cardiovascular risk profiles. Patient reports often cite significant functional improvement, though some report gastrointestinal discomfort. Topical formulations receive positive feedback for localized relief with minimal systemic effects. Long-term real-world evidence supports its role in chronic inflammatory conditions when used judiciously under supervision.