Colchicine prevents acute gouty arthritis attacks by:

• A Inhibiting xanthine oxidase, reducing uric acid synthesis
• B Binding to tubulin dimers and preventing microtubule polymerisation, impairing neutrophil migration and phagocytosis ✓
• C Competitively blocking urate reabsorption in the proximal renal tubule
• D Inhibiting NLRP3 inflammasome activation by blocking IL-1beta directly

Explanation

Colchicine binds reversibly to tubulin dimers, preventing their assembly into microtubules. Microtubules are essential for neutrophil chemotaxis, phagocytosis of monosodium urate crystals, and degranulation. By impairing these functions, colchicine interrupts the inflammatory cascade triggered by urate crystals without affecting uric acid levels. It also inhibits NLRP3 inflammasome assembly (which requires microtubule-mediated transport), reducing IL-1beta maturation, but the primary mechanism is tubulin binding.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.