Given the patient's medication regimen, what is the most likely pharmacokinetic interaction between simvastatin and warfarin that a physician should monitor for?
Increased risk of simvastatin side effects due to CYP3A4 inhibition by warfarin Decreased efficacy of simvastatin due to CYP2C9 competition with warfarin Reduced effectiveness of warfarin due to competitive binding with simvastatin at CYP2C9 Increased bleeding risk due to CYP3A4-mediated interaction increasing warfarin levels