A 68-year-old man has been taking the nitrate isosorbide dinitrate (Isordil) for 2 years for angina. He recently has been experiencing erectile dysfunction and wants a prescription for sildenafil...

A 68-year-old man has been taking the nitrate isosorbide dinitrate (Isordil) for 2 years for angina. He recently has been experiencing erectile dysfunction and wants a prescription for sildenafil (Viagra). Which response would the nurse most likely hear from the prescriber? a “He will have to be switched to isosorbide mononitrate if he wants to take sildenafil.” b “Taking sildenafil with the nitrate may result in severe hypotension, so a contraindication exists.” c “I’ll write a prescription, but if he uses it, he needs to stop taking the isosorbide for one dose.” d “These drugs are compatible with each other, and so I’ll write a prescription.”