Problem:
A male patient with cardiovascular disease is taking isosorbide dinitrate for the treatment of angina pectoris. A review of his medications reveals a medication that he also takes sildenafil (Viagra) for erectile dysfunction. What advice should the primary care provider give to this patient? A) "Only take the sildenafil on a day when you do not experience chest pain." B) "Sildenafil should be taken with isosorbide dinitrate before sexual activity." C) "Sildenafil and nitrates can cause severe hypotension, fainting, or even myocardial infarction." D) "You can take the sildenafil safely for sexual activity if it has been at least 6 hours since your isosorbide dinitrate dose."