<prompt> You decide not to prescribe Sildenafil in a patient because the patient is on an antianginal drug. Which of the following can it be?Calcium channel blockersBeta blockersOrganic nitratesACE inhibitors  <response>: sildenafil and nitrates are contraindicated to be given in combination since both of them cause vasodilation of vessels and can lead to hypotension. Ref: KD Tripathi 8th ed. 