Following a myocardial infarct, a patient is stabilized on warfarin, with the dose adjusted to give a prothrombin time of 22 seconds. Which one of the following statements regarding potential drug interactions in this patient is accurate?
Cholestyramine will increase prothrombin time. Cimetidine is likely to decrease prothrombin time. Antibacterial sulfonamides may enhance the effects of warfarin. Vitamin K would restore prothrombin time to normal within 30 minutes.