A large proportion of patients who have erectile dysfunction also have coronary artery disease (CAD). In these patients, nitrate therapy is a contraindication to the use of sildenafil. To assess whether the metabolic anti-ischemic agent, trimetazidine, is effective in controlling episodes of myocardial ischemia during sexual activity in patients who have CAD and use long-term nitrate therapy, we studied 38 men (57 +/- 6 years of age) who had proved CAD. Patients underwent 24-hour ambulatory electrocardiographic monitoring at baseline, after 1 week of oral nitrate therapy (20 mg 3 times a day), and after 1 week of trimetazidine (20 mg 3 times a day). Patients were asked to engage in >/=1 session of sexual intercourse during each session of ambulatory electrocardiographic monitoring. They were instructed to take sildenafil (100 mg) 1 hour before sexual intercourse performed at baseline and during therapy with trimetazidine and sildenafil or placebo (blinded) during therapy with nitrates. A decrease in total ischemic burden was observed with nitrates and trimetazidine compared with baseline (-3 +/- 1.2 episodes/patient/24 hours vs -5 +/- 1.3 episodes/patient/24 hours and -6 +/- 5 min/patient/24 hours vs -8 +/- 3 min/patient/24 hours, p <0.01 for nitrates and trimetazidine vs baseline). Trimetazidine plus sildenafil was more effective in controlling episodes of myocardial ischemia during sexual activity than nitrates alone (-45 +/- 11% vs -18 +/- 7%, p <0.04). In conclusion, in patients who have CAD, combination therapy with sildenafil and trimetazidine is more effective than nitrate therapy in the control of ischemic episodes during sexual activity, suggesting that long-term nitrate therapy may be safely switched to trimetazidine therapy when therapy for erectile dysfunction is required.