Colchicine: serious interactions.

(1) Renal failure, either pre-existing or induced by a nephrotoxic drug, increases the risk of adverse effects in patients taking colchicine; (2) Combining colchicines with a macrolide (except for spiramycin) carries a risk of life-threatening pancytopenia; (3) Ciclosporin co-administration can aggravate the neuromuscular adverse effects of colchicine; (4) Combining colchicine with lipid-lowering drugs (statins and fibrates) can cause myopathy; (5) Several mechanisms have been implicated: competition for cytochrome P450 or P-glycoprotein, additive adverse effects (especially on muscle), and colchicine accumulation due to a reduction in its renal excretion; (6) Patients with gout should use colchicine only after failure of symptomatic treatment: ice application, paracetamol, and possibly ibuprofen, a nonsteroidal antiinflammatory drug with well-documented adverse effects; (7) If colchicine is nevertheless used, it should be at the minimum effective dose. Close clinical monitoring is required in order to detect early signs of adverse effects, especially diarrhoea, the earliest sign in patients with renal failure and in the elderly.