Colchicine Colchicine is neither analgesic nor anti- inflammatory, but it specifically suppresses gouty inflammation. It does not inhibit the synthesis or promote the excretion of uric acid. Thus, it has no effect on blood uric acid levels. pathophysiology of gout:- An acute attack of gout is staed by the precipitation of urate crystals in the synol fluid. On being engulfed by the synol cells, they release mediators and sta an inflammatory response. Chemotactic factors are produced - granulocyte migration into the joint; they phagocytose urate crystals and release a glycoprotein which aggravates the inflammation by: (i) Increasing lactic acid production from inflammatory cells - local pH is reduced - more urate crystals are precipitated in the affected joint. (ii) Releasing lysosomal enzymes which cause joint destruction. mech of action of colchicine:- Colchicine does not affect phagocytosis of urate crystals, but inhibits release of chemotactic factors and of the glycoprotein, thus suppressing the subsequent events. By binding to fibrillar protein tubulin, it inhibits granulocyte migration into the inflamed joint and thus interrupts the vicious cycle Toxicity:- Nausea, vomiting, watery or bloody diarrhoea and abdominal cramps occur as dose limiting adverse effects. Ref:- kd tripathi; pg num:-214