Non-steroidal anti-inflammatory drugs (NSAIDs)
ATC code: M01AB05 (Diclofenac)
Non-selective cyclooxygenase inhibitor with greater COX-2 selectivity than ibuprofen. Potent anti-inflammatory effect through prostaglandin synthesis suppression and inhibition of leukocyte migration to the site of inflammation. Analgesic onset within 20-30 minutes of oral intake. Available as oral, rectal, intramuscular, and topical formulations.
First line
Diclofenac 50 mg 2-3 times daily or 75 mg twice daily is one of the most effective NSAIDs for pain of various origins. Maximum daily dose 150 mg. Surpasses ibuprofen in analgesic potency. Short course of 5-7 days is preferred. If prolonged use is needed, cardiovascular and gastrointestinal risk must be assessed.
First line
For osteoarthritis, OA 2022 recommends starting with topical NSAIDs – diclofenac gel applied to the affected joint 3-4 times daily. Topical form provides local effect with minimal systemic exposure. Oral diclofenac is used when topical therapy is insufficient. Due to high cardiovascular risk, short courses are preferred.
First line
Diclofenac is first-line for renal colic. Administered intramuscularly 75 mg or rectally 100 mg. Efficacy is comparable to opioid analgesics with less nausea and vomiting. A 2015 Cochrane review confirmed NSAIDs' advantage over antispasmodics in renal colic.
Adjunct
Diclofenac is used as symptomatic treatment in rheumatoid arthritis to reduce pain and stiffness. NSAIDs do not affect disease progression – disease-modifying therapy (methotrexate etc.) is mandatory. Prescribed at the lowest effective dose during flares.
FDA category C in the first and second trimesters. Contraindicated in the third trimester (category D) due to risk of premature ductus arteriosus closure and oligohydramnios. Avoid after 20 weeks.
Excreted in breast milk in small amounts. Short-term use is acceptable. If prolonged treatment is needed, ibuprofen is preferred.
diclofenac is evaluated for the following indications with varying evidence strength: Rheumatoid arthritis (evidence tier A), Renal colic (evidence tier A), Mild to moderate pain in adults (evidence tier A). See the full indication matrix with dosing and citations above on this page.
Common side effects of diclofenac (≥ 1 in 100): Dyspepsia, epigastric pain, nausea, Headache, dizziness, Elevated liver transaminases, Fluid retention, edema. See the Safety section for uncommon and serious reactions.
FDA category C. FDA category C in the first and second trimesters. Contraindicated in the third trimester (category D) due to risk of premature ductus arteriosus closure and oligohydramnios. Avoid after 20 weeks.
Excreted in breast milk in small amounts. Short-term use is acceptable. If prolonged treatment is needed, ibuprofen is preferred.
diclofenac is contraindicated in: Established coronary artery disease, prior MI or stroke; Heart failure (NYHA II-IV); Uncontrolled arterial hypertension; Active peptic ulcer disease or GI bleeding; Severe renal impairment (eGFR below 30). Full list in the Safety section.