Interacting drug pair n Outcome Mechanism
amiodarone-colchicine 1* Increased colchicine plasma concentrations and increased risk of colchicine toxicity Inhibition of P-glycoprotein-mediated colchicine efflux transport
amiodarone-digoxin 4* Digoxin toxicity (nausea, vomiting, cardiac arrhythmias) and potentiated effects of amiodarone Inhibition of p-glycoprotein by amiodarone, and reduction of digoxin clearance; interference with amiodarone by digoxin
amiodarone-fluconazole 8* Increased amiodarone exposure and an increased risk of cardiotoxicity Inhibition of CYP3A4-mediated amiodarone-metabolism; additive QT-interval prolongation
amiodarone-rifampin 3* Decreased efficacy of amiodarone CYP450-mediated induction of amiodarone metabolism
amiodarone-warfarin 15* Increased risk of bleeding Increased exposure to warfarin
clopidogrel-omeprazole 12* Reduced plasma concentrations of clopidogrel active metabolite and reduced antiplatelet activity Inhibition of CYP2C19-mediated clopidogrel metabolism to active metabolite by omeprazole
fluconazole-tacrolimus 2* Increased tacrolimus exposure and risk of tacrolimus toxicity, including QT-interval prolongation Inhibition of CYP3A4-mediated tacrolimus metabolism by fluconazole; additive effects on QT-interval prolongation
fluconazole-warfarin 6* Increased risk of bleeding Disruption of vitamin K synthesis; inhibition of CYP3A4-mediated warfarin metabolism
isosorbide-sildenafil 1* Potentiation of hypotensive effects Increased levels of cyclic guanosine monophosphate from sildenafil and nitrates
amiodarone-simvastatin 3 Increased exposure to simvastatin and an increased risk of myopathy or rhabdomyolysis Inhibition by amiodarone of CYP3A4-mediated simvastatin metabolism
amlodipine-simvastatin 1 Increased simvastatin exposure and increased risk of myopathy, including rhabdomyolysis Unknown
atorvastatin-colchicine 1 Increased colchicine exposure; an increased risk of myopathy or rhabdomyolysis Inhibition of hepatic and renal p- glycoprotein mediated colchicine transport by atorvastatin; unknown
atorvastatin-diltiazem 1 Increased risk of rhabdomyolysis Inhibition by diltiazem of cytochrome P450 3A4-mediated atorvastatin metabolism
esomeprazole-tacrolimus 1 Increased tacrolimus exposure Inhibition of CYP3A4-mediated tacrolimus metabolism by esomeprazole
lamotrigine-primidone 1 Decreased lamotrigine efficacy Hepatic induction of lamotrigine metabolism
metronidazole-warfarin 1 Increased risk of bleeding Potentiation of anticoagulation; prolonged prothrombin time
omeprazole-tacrolimus 5 Increased tacrolimus exposure Inhibition of CYP3A4-mediated tacrolimus metabolism by omeprazole