Colchicine

The clinical pharmacology of colchicine has been reviewed and its therapeutic use described. There is still some disagreement about its diagnostic utility; it is clearly most effective in acute gout, but benefit has been reported from its use in sarcoid arthritis and in the inflammation associated with hydroxyapatite deposition.Colchicine toxicity is largely gastrointestinal in customary doses, with a choleriform syndrome of varying severity produced in 80% of patients. Larger doses in addition produce disseminated intravascular coagulation, marrow failure, hepatocellular failure, and late central-nervous-system dysfunction, among other effects. Treatment of colchicine toxicity is supportive.Colchicine metabolic studies demonstrate that the drug leaves the blood rapidly and remains in cells for protracted periods of time. Measurable amounts were still found in leukocytes as late as 10 days after a single administration, and urinary excretion persisted for a similar length of time.A comparison of the relation between function and the structure of colchicine and its analogues in the human and in two species of rodent revealed significant variability in results. It was concluded that urate crystal-induced inflammation in the rodent was not necessarily a suitable model for human acute gout.Studies of colchicine's mechanism of action in acute gout have previously suggested that it depended on interference with microtubular subunit protein aggregation. Evidence is here summarized that colchicine may have other effects on the cell and that the benefit in gout may possibly be unrelated to the microtubular action.