Definition
- Non-steroidal anti-inflammatory drugs inhibit cyclo-oxygenase and reduce prostaglandin synthesis
- Analgesic, anti-inflammatory and antipyretic
- Most are weak acids with high protein binding
Classification
| Group | Examples | Notes |
|---|---|---|
| Non-selective | Ibuprofen, naproxen, diclofenac, indomethacin | Reversible COX-1 and COX-2 inhibition |
| COX-2 selective | Celecoxib, etoricoxib, parecoxib | Less gastric toxicity, no antiplatelet effect |
| Aspirin | Aspirin | Irreversible COX inhibition. Antiplatelet effect lasts the life of the platelet |
Adverse Effects
- Gastric ulceration and bleeding
- Acute kidney injury, worse with dehydration, ACE inhibitors and diuretics
- Thrombotic cardiovascular risk with COX-2 inhibitors and diclofenac
- Bleeding from platelet inhibition with non-selective agents
- Bronchospasm in aspirin sensitive asthma
- Use the lowest dose for the shortest time
- Add a proton pump inhibitor in patients at risk of gastrointestinal bleeding
- Avoid in late pregnancy because of premature ductus arteriosus closure
- Fluid retention and raised blood pressure
Clinical Use
- Part of multimodal analgesia after arthroplasty
- Indomethacin or radiotherapy for prophylaxis against heterotopic ossification after hip surgery
- Topical NSAIDs for hand and knee osteoarthritis with fewer systemic effects
- Parecoxib intravenously when oral intake is not possible
Orthopaedic Relevance
- Animal studies show delayed fracture and spinal fusion healing
- Clinical evidence is mixed. Short courses appear safe
- Indomethacin is used as heterotopic ossification prophylaxis after hip surgery
- See COX and Multimodal Pain Management
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.