Cardiovascular safety of sublingual apomorphine in patients on stable doses of oral antihypertensive agents and nitrates

Sublingual (SL) apomorphine (2 to 6 mg) has been shown to be effective for treatment of male erectile dysfunction. Many patients with erectile dysfunction are also being treated for systemic hypertension and/or cardiovascular disease. In a double-blind, randomized, placebo-controlled, crossover trial, SL apomorphine 5 mg and placebo were administered on alternate days to 162 men who were on long-term therapy (≥4 weeks) with angiotensin-converting enzyme inhibitors, β blockers, diuretics, calcium channel blockers, α1 blockers, or short- or long-acting nitrates. Blood pressure and heart rate were measured before and after dosing; cardiac rhythm was recorded by 4-hour Holter monitoring. The only potentially clinically significant interactions between SL apomorphine and the antihypertensive agents or short-acting nitrates were greater orthostatic decreases in systolic blood pressure in the α-blocker and calcium channel blocker groups (−10 and −6 mm Hg vs placebo, respectively). Administration of SL apomorphine after dosing with long-acting nitrates resulted in significant decreases in blood pressure when patients were standing (mean systolic change, −5 to −9 mm Hg 30 to 60 minutes postdose, p <0.05; mean diastolic change, −3 to −4 mm Hg 50 to 60 minutes postdose, p <0.05). The most common adverse events with SL apomorphine were dizziness, nausea, and headache. Syncope occurred in 1 patient in the β-blocker group; symptomatic hypotension occurred in 2 patients each in the short- and long-acting nitrate groups. Thus, in patients receiving common antihypertensive agents and short-acting nitrates, as well as in most patients receiving long-acting nitrates, SL apomorphine at higher than recommended doses produced no clinically significant changes in heart rate or blood pressure greater than changes seen with SL apomorphine alone.