PLASMA MHPG RESPONSE TO YOHIMBINE TREATMENT IN WOMEN WITH HYPOACTIVE SEXUAL DESIRE

The use of yohimbine to treat impotence has suggested that decreased m ale sexual desire may relate to decreased activity of central noradren ergic neurons. Previous trials of yohimbine to treat female sexual pro blems are not available. Yohimbine is an alpha(2)-adrenergic antagonis t that stimulates norepinephrine (NE) release. In the present study, p lasma concentrations of 3-methoxy-4-hydroxyphenylglycol (MHPG), the ma jor central nervous system metabolite of NE, were measured in 9 women diagnosed with hypoactive sexual desire. Daily logs of mood and sexual activity, and trimonthly MHPG blood drawings, were obtained over an i nitial baseline menstrual cycle followed by two subsequent treatment c ycles (yohimbine or placebo), in randomized order Blood samples were o btained at 9:00 a. m. during (a) the early follicular phase of each cy cle (24 hr after the onset of each cycle), (b) the ovulatory phase (i. e., within I day of an oral temperature rise), and (c) the midluteal P hase (i.e., 20-25 days into each cycle). Comparisons were made with a group of 7 healthy female controls. Women with hypoactive sexual desir e had slightly lower plasma MHPG values than controls at baseline, alt hough there was only a trend toward significance during the Early foll icular phase (p = .09). Yohimbine (5.4 mg orally, 3 times daily, begin ning at menses) caused a sustained rise in plasma MHPG of similar magn itude to that reported in men. However, in terms of improved sexual de sire, yohimbine had no obvious therapeutic effect. Thus, plasma MHPG a nd the alpha(2)-adrenergic response to yohimbine appeared within norma l ranges in women with hypoactive sexual desire, with no therapeutic r esponse to yohimbine.