NSAIDs

  • Mechanism of action: reversible inhibition of COX1

  • naproxen / diclofenac - similar efficacy

  • naproxen - more potent than ibuprofen

  • gout - you want something with more anti-inflammatory effect than ibuprofen - naproxen, diclofenac will do you

Risk of NSAID-induced GI adverse events NSAIDs
Lowest risk Ibuprofen
Intermediate risk Naproxen, diclofenac, indometacin
Highest risk Piroxicam, ketoprofen, ketorolac

From Rang and Dale:

  • Ibuprofen: half-life 2h (when given PO)
  • Diclofenac: (moderate potency, half-life 1–2h)
  • Ketoprofen (half-life ~2h;)
  • ketorolac (half-life 4–10h, COX-1 selective)
  • Naproxen (more potent, half-life 10–14h)
  • piroxicam (half-life 57h, GIT toxicity common, COX non-selective).

common s/e

  • GI upset - ↓ prostaglandin = less gastro-protection
  • psoriasis

mefenamic acid

  • specifically for dysmenorrhea
  • specific s/e:
    • proctocolitis
    • haemolytic anaemia (reversible when drug is stopped)

#pharmacology #analgesia