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ORIGINAL RESEARCH—PHARMACOTHERAPY: Hemodynamic Effects of Sildenafil Citrate and Isosorbide Mononitrate in Men with Coronary Artery Disease and Erectile Dysfunction


Graham Jackson, St. Thomas Hospital, Cardiac Department, Lambeth Palace Road, London, SE1 7 EH, UK. Tel: 44 (207) 407-5887; Fax: 44 (207) 357-7408; E-mail:


Introduction.  Mild hemodynamic effects have been reported with sildenafil citrate therapy.

Aim.  To compare the hemodynamic effects of sildenafil and isosorbide mononitrate (ISMN) in men with coronary artery disease and erectile dysfunction.

Methods.  A total of 31 men aged 35 years or older with coronary artery disease (at least 50% narrowing of the left main stem or at least 70% narrowing of any other coronary artery) and erectile dysfunction (receiving medication for erectile dysfunction or scoring less than 26 out of a maximum score of 30 on the erectile function domain questions of International Index of Erectile Function) were randomized to sildenafil 100 mg (n = 10), ISMN 40 mg (n = 11), or placebo (n = 10) in this single-dose multicenter study.

Main Outcome Measures.  Hemodynamic parameters were measured at baseline, 1, 2, 4, and 6 hours post dose.

Results.  Compared with baseline, cardiac index increased slightly with sildenafil (0.29 L/min/m2 at 1 hour) and decreased slightly with placebo (−0.12 L/min/m2 at 4 hours) and ISMN (−0.14 L/min/m2 at 1 hour). The stroke volume index increased from baseline at each time point post dose with sildenafil (4.4 mL/m2 at 2 hours), but decreased with ISMN (−5.8 mL/m2 at 1 hour) and placebo (−2.8 mL/m2 at 4 hours). ISMN reduced mean arterial pressure more than sildenafil did (−22 vs. −10 mm Hg at 2 hours, respectively). Both sildenafil and ISMN increased heart rate (4 vs. 7 beats/minute at 1 hour, respectively) and decreased systemic vascular resistance, but sildenafil produced greater reductions in pulmonary vascular resistance. There were no serious adverse events in the sildenafil group.

Conclusions.  Sildenafil 100 mg was well tolerated and induced smaller changes in central and peripheral hemodynamic pressures compared with ISMN 40 mg. Moreover, sildenafil selectively reduced pulmonary resistance, which may have clinical importance in pulmonary hypertension.