diclofenac

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain, inflammation, and fever. It is available in multiple forms: oral tablets (immediate- or extended-release), topical gels and creams, transdermal patches, ophthalmic solutions, rectal suppositories, and injectable formulations.

Diclofenac works by inhibiting cyclooxygenase enzymes COX-1 and COX-2, reducing prostaglandin synthesis. It is used for conditions such as osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, dental pain, post-traumatic and postoperative pain, menstrual pain, and episodic migraine (in certain formulations). Topical diclofenac is often used for localized musculoskeletal pain.

Common adverse effects include gastrointestinal irritation (gastritis, ulcers, bleeding), nausea, and abdominal pain. NSAIDs may increase the risk of cardiovascular events and renal impairment, especially with long-term use or in persons with risk factors. Liver enzyme elevations and hypersensitivity reactions can occur. Caution is advised in older adults, persons with peptic ulcer disease, renal or hepatic impairment, pregnancy (especially during the third trimester), and those taking anticoagulants or other NSAIDs.

Dosing varies by product and condition; many regimens use multiple times daily dosing for oral forms. Notable drug interactions include anticoagulants, antiplatelet agents, corticosteroids, methotrexate, and antihypertensives. Diclofenac with misoprostol reduces GI risk (Arthrotec). Topical diclofenac reduces systemic exposure. Always use the lowest effective dose for the shortest duration. Regulatory status spans prescription and nonprescription products in some regions.