Major
Colchicine × Verapamil
Antigout agents×Non-dihydropyridine calcium channel blocker
Mechanism
Verapamil blocks CYP3A4 and the P-glycoprotein transporter – two colchicine clearance routes. Colchicine plasma levels rise; myopathy, neuropathy, and pancytopenia risks grow.
Symptoms
Profuse diarrhoea, vomiting, abdominal pain. With prolonged combination: muscle weakness, peripheral neuropathy, falling leukocytes and platelets.
Management
In chronic kidney disease or hepatic impairment, do not prescribe. With preserved function: colchicine 0.3 mg every other day for no more than 5 days. Alternative for gout on verapamil: intra-articular or short systemic glucocorticoid.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.