Report of erectile dysfunction after therapy with beta-blockers is related to patient knowledge of side effects and is reversed by placebo

AIMS: Patients with cardiovascular diseases frequently complain of erectile dysfunction especially when treated with beta-blockers. In order to assess whether the effect of beta-blockers on erectile dysfunction is in part related to patient knowledge of the drug side effects, 96 patients (all males, age 52+/-7 years) with newly diagnosed cardiovascular disease and not suffering from erectile dysfunction entered a two phase, single cross over study. METHODS AND RESULTS: During the first phase of the study patients received atenolol 50mg o.d. (A), 32 patients were blinded on the drug given (group A), 32 were informed on the drug given but not on its side effects (group B) and 32 took A after being informed on its side effects on erectile function (group C). After 3 months the incidence of erectile dysfunction was 3.1% in the group A, 15.6% in group B and 31.2% in group C (P<0.01). All patients reporting ED entered the second phase of the study and were randomised to receive Sildenafil 50mg and placebo in a cross over study. Sildenafil citrate and placebo were equally effective in reversing erectile dysfunction in all but one patient reporting ED with Atenolol. CONCLUSION: Our results show that the knowledge and prejudice about side effects of beta-blockers can produce anxiety, that may cause erectile function.