Yohimbine effects on blood pressure and plasma catecholamines in human hypertension*

Abstract

The purpose of this study has been to test the hypothesis of an alpha 2-adrenoreceptor alteration in human essential hypertension. The design of the study involved the oral administration of 10 mg yohimbine, an alpha 2-adrenergic antagonist, to 25 healthy volunteers and 29 sex- and age-matched untreated hypertensive patients. Volunteers and patients were studied twice in random order, after placebo or yohimbine treatment, in supine and upright positions. Arterial pressure and heart rate were monitored by servoplethysmomanometry, and venous plasma catecholamines were determined by HPLC with electrochemical detection. Yohimbine induced a significant increase in diastolic pressure only in the hypertensive patients. Plasma norepinephrine was increased significantly in both yohimbine-treated groups, but the percent increase of plasma norepinephrine after the standing test was decreased significantly only in the healthy yohimbine-treated subjects. Plasma dopamine was increased significantly only in the healthy yohimbine-treated subjects. The response of plasma dopamine to the upright position was modified only in the healthy yohimbine-treated subjects. The decrease observed after 2 min of standing was abolished, showing the involvement of alpha 2-adrenoreceptors in the physiologic response of plasma catecholamines in healthy volunteers. Our data may be consistent with some in vivo evidence of an alpha 2-adrenoreceptor desensitization or an alteration in the balance of alpha-adrenoreceptors in human hypertension.

Effects of Acute Yohimbine Hydrochloride Supplementation on Repeated Supramaximal Sprint Performance

“…YHM has been repeatedly shown to increase catecholamine levels, principally NE [1,11,40]. In the current study, acute YHM ingestion resulted in greater EPI levels pre-and postexercise while NE increased post-exercise independent of treatment.…”

Interacción entre fármacos y plantas medicinales

“…La yohimbina (Pausinystalia yohimbe) puede antagonizar los efectos de guanabenz y metildopa por propiedades antiadrenérgicas α2 [42][43][44][45][46] .…”

Scientific Opinion on the evaluation of the safety in use of Yohimbe (Pausinystalia yohimbe (K. Schum.) Pierre ex Beille)

“…In the study of Musso et al (1995), 10 mg yohimbine induced a significant increase in diastolic pressure only in the hypertensive patients and not in the healthy controls. Plasma noradrenaline was increased significantly in both yohimbine-treated groups, but the percent increase of plasma noradrenaline after the standing test was decreased significantly only in the healthy yohimbine-treated subjects.…”

“…Human data encompass several case reports with yohimbine intoxications for which severe symptoms (hypertensive crisis, manic symptoms, anxiety, agitation, loss of consciousness) have been described (Price et al, 1984;Pittler et al, 2005;Giampreti et al, 2009). Clinical studies have been performed in a whole array of indications such as erectile dysfunction (Morales et al, 1987;Riley et al, 1989;Susset et al, 1989;Kunelius et al, 1997;Vogt et al, 1997;Teloken et al,1998), panic disorders (Gurguis, 1997), hypertension (Damase-Michel et al, 1993Musso et al, 1995) and orthostatic hypotension (Jordan et al, 1998). Doses between 5.4 mg and 100 mg daily were used whereby doses up to 18 mg daily elicited no subjective side effects but doses as low as 5.4 mg resulted in significant increases in systolic blood pressure (Jordan et al, 1998).…”