Amiodarone × Colchicine

Amiodarone blocks CYP3A4 and the P-glycoprotein transporter – two colchicine clearance routes. Colchicine plasma levels rise; myopathy and neuropathy risk grows.

Muscle weakness and pain, peripheral neuropathy (numbness, tingling in feet and hands), nausea, diarrhoea. Severe cases include pancytopenia and rhabdomyolysis. Symptoms appear within 1–4 weeks of co-administration.

Do not prescribe in chronic kidney disease or impaired hepatic function. With preserved function, reduce colchicine to 0.3 mg every other day. Alternative for gout on amiodarone: intra-articular or short systemic glucocorticoid.