A 58-year-old man complains of chest discomfort and nausea. He is conscious and alert; his blood pressure is 140/90 mm Hg, his pulse is 104 beats/min, and his respirations are 16 breaths/min. Your partner has applied supplemental oxygen. Prior to assisting the patient with one of his prescribed nitroglycerin tablets, you ask him if he takes medication to treat erectile dysfunction and he tells you that he does. You should:
-ask him what he takes, how much, and when he last took it.