Effect of clonidine on hot flashes in postmenopausal women.

The effectiveness of clonidine in suppressing the occurrence of postmenopausal hot flashes was examined using a dose-response study design and objective recordings of hot flashes. Patients with frequent flashes were studied before and after oral administration of placebo and 0.1, 0.2, and 0.4 mg of clonidine daily for 2 weeks at each dose level. Finger temperature and skin resistance were recorded as indices of hot flash episodes. Four of 10 subjects beginning the study withdrew because of drug-related side effects. Clonidine was found to reduce significantly the frequency of hot flashes as compared with baseline (P less than .005) and with effects of the placebo (P less than .05). At the maximum dosage the mean rate of hot flash occurrence decreased 46%. It was concluded that clonidine does reduce the frequency of postmenopausal flashes.