The effect of nimesulide and naproxen on the uterine and ovarian arterial blood flow velocity. A Doppler study

BACKGROUND: To measure the effect of oral naproxen and nimesulide treatments on the uterine and ovarian arterial blood flow velocity in both eumenorrheic and dysmenorrheic women. METHODS: The double-blind, placebo-controlled, study comprised six eumenorrheic women receiving either placebo or nimesulide (100 mg, single oral dose) during two consecutive cycles. Six women with moderate to severe dysmenorrhea were treated with placebo, nimesulide or naproxen (500 mg, single oral dose) during three consecutive cycles. Uterine impedance (pulsatile index, PI) was measured during the cycle day 1 at four different levels of the uterus and in the ovarian branch of the uterine artery at 0, 30, 60, and 120-140 min, with a color Doppler ultrasonograph for orientation and with pulsatile Doppler for recording waveforms. RESULTS: In the eumenorrheic women no significant changes were found with any treatment. In dysmenorrheic patients, nimesulide relieved symptoms and caused a decrease in uterine artery PI earlier than naproxen. Both treatments reduced the elevated uterine impedance in dysmenorrhea close to the normal level. When analyzing the PIs of the uterine artery at 4 different levels, the most prominent changes were observed in the fundus. The ovarian branch remained unaffected. CONCLUSIONS: Color Doppler ultrasonography and pulsatile Doppler are good methods for investigating disease- or drug-induced changes in uterine and ovarian blood flow velocities. Nimesulide induced a slightly faster and more complete decrease of the elevated uterine vascular resistance in dysmenorrhea, towards normal eumenorrheic levels, than naproxen. The fundal part of the uterus appears to be an important site of the pathogenesis in primary dysmenorrhea.