The effect of sildenafil citrate on uterine and clitoral arterial blood flow in postmenopausal women.

OBJECTIVE: The aim of this study was to determine the effect of sildenafil on the uterine circulation and clitoral artery blood flow in postmenopausal women using color Doppler sonography.
METHODS: The study population consisted of 25 volunteer naturally postmenopausal women (mean age, 50.2 +/- 3.6 years). Color Doppler sonography was performed to measure the resistance and pulsatility indexes of the uterine arteries and peak systolic velocity, resistance, and pulsatility indexes of the clitoral arteries. One hour after administration of a single oral dose of 50 mg sildenafil citrate, the Doppler sonographic examination was repeated.
RESULTS: After sildenafil administration, the mean resistance and pulsatility indexes of uterine artery were significantly lower (0.73 +/- 0.08 vs 0.80 +/- 0.07, P < .001 and 1.66 +/- 0.50 vs 2.08 +/- 0.52, P < .001, respectively) in comparison to baseline values, and the mean peak systolic velocity of clitoral artery was significantly higher (17.9 +/- 8.6 cm/sec vs 12.9 +/- 5.8 cm/sec, P < .001). Sildenafil did not cause any significant change in the mean resistance and pulsatility indexes of the clitoral artery (P = .683 and P = .714, respectively).
CONCLUSION: Sildenafil improves the clitoral and uterine blood flow in healthy postmenopausal women without any erotic stimulus. Further studies are needed to determine whether there are roles for sildenafil therapy in postmenopausal women and evaluation of clitoral blood flow by Doppler sonography.