Mechanism of action and pharmacokinetics of colchicine
- • Irreversibly binds free tubulin dimers → disrupts microtubule polymerization → inhibition of neutrophil chemotaxis, phagocytosis, and cytokine secretion.
- • Inhibits phospholipase A2, which leads to lower levels of inflammatory prostaglandins and leukotrienes (LTB4).
- • May modulate pyrin expression.
- • Colchicine is not bound to plasma proteins and is highly lipid-soluble, readily passing into all tissues.
- • Colchicine achieves much higher intraleukocyte concentrations than plasma concentration—can be detected in neutrophils up to 10 days after a single dose!
- • Hepatic metabolism, predominantly excreted in feces; 40% to 65% excreted unchanged in urine.
