Effects of sildenafil citrate (Viagra) on hemodynamic parameters during exercise testing and occurrence of ventricular arrhythmias in patients with erectile dysfunction and cardiovascular disease.
BACKGROUND: Erectile dysfunction (ED) is frequently observed in male cardiovascular disease (CVD) patients, creating concern about cardiac risk of their sexual activity, and their therapeutic use of sildenafil. Relatively little information exists about sildenafil effects on exercise testing, hemodynamic parameters or on occurrence of ventricular arrhythmias during normal activities in CVD patients. HYPOTHESIS: Single, oral doses of sildenafil do not significantly affect exercise-induced changes in hemodynamic parameters or occurrence of arrhythmias in ED/CVD patients. METHODS: ED patients, with or without CVD, were enrolled in one of two studies. In the first, patients underwent standard (Bruce Protocol) treadmill tests; an initial control test was followed 1 hour later by administration of 100mg oral sildenafil. After another hour, they underwent a second treadmill test. Systolic and diastolic blood pressure (SBP and DBP), heart rate, and double product were determined for each evaluation at pretest, maximum stress, and recovery. In the second, Holter ambulatory ECGs were recorded 5 hours before and 6 hours after 100mg oral sildenafil administration. RESULTS: Sildenafil had no clinically significant effects on exercise-induced changes in hemodynamic parameters in cardiac patients and only slight, clinically insignificant effects in noncardiac patients. ECG showed sildenafil did not affect incidence of ventricular arrhythmias. CONCLUSIONS: Sildenafil does not alter hemodynamic response to exercise or change incidence of ventricular arrhythmias in men with CVD and ED. These results suggest that, when used in accordance with prescribing information and current treatment guidelines, sildenafil should be safe for most patients with both these conditions.