Probable drug-drug interaction between erlotinib and amiodarone causes severe neurotoxicity in a patient with advanced lung cancer.

Drug-drug interactions (DDIs) are of great concern in the treatment of cancer, especially when target therapies, such as tyrosine kinase inhibitors, are being used. Here, we report a case of probable DDI between erlotinib and amiodarone leading to severe neurotoxicity. Amiodarone inhibits P-glycoprotein (P-gp), for which erlotinib is a substrate.