Reduction of menopausal hot flushes by methyldopa. A double blind crossover trial.

In a double-blind study, methyldopa was shown to be significantly more effective than placebo in reducing menopausal hot flushes. The median reduction in the number of hot flushes was 38% with placebo and 65% with methyldopa. The active metabolite of methyldopa, alpha-methylnoradrenaline, is an alpha 2-adrenoceptor agonist. Since the alpha 2-adrenoceptor agonist clonidine also reduces hot flushes, while the alpha 2-adrenoceptor antagonist yohimbine produces flushes, it is speculated that menopausal hot flushes might result from a reduced stimulation of alpha 2-adrenoceptors, probably in the CNS.