Hypertensive Urgency: An Undesirable Complication of a "Male Performance" Herbal Product.

BACKGROUND: Hypertensive urgency is a clinical scenario that may be associated with herbal supplement use and that requires special consideration with regard to emergency department management. CASE REPORT: A 49-year-old man presented to the emergency department with palpitations and severely elevated blood pressure without evidence of end organ dysfunction. Hypertension failed to be controlled with multiple doses of oral clonidine and intravenous labetalol. The patient later admitted to using an herbal supplement containing yohimbine, a selective ⍺2-adrenoreceptor antagonist specifically linked to cases of refractory hypertension. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Between 17-35% of the U.S. adult population may use herbal supplements on a sporadic or regular basis; pharmacologically active agents in herbal supplements may affect both a patient's presentation and response to treatment. Most patients do not mention over-the-counter and herbal products in their medication profile unless specifically asked, and therefore it is important for emergency physicians to be aware of the pharmacologic effects of herbal supplements in the evaluation and treatment of refractory severe hypertension.

Quantification of [(11)C]yohimbine binding to α2 adrenoceptors in rat brain in vivo.

We quantified the binding potentials (BPND) of [(11)C]yohimbine binding in rat brain to alpha-2 adrenoceptors to evaluate [(11)C]yohimbine as an in vivo marker of noradrenergic neurotransmission and to examine its sensitivity to the level of noradrenaline. Dual [(11)C]yohimbine dynamic positron emission tomography (PET) recordings were applied to five Sprague Dawley rats at baseline, followed by acute amphetamine administration (2 mg/kg) to induce elevation of the endogenous level of noradrenaline. The volume of distribution (VT) of [(11)C]yohimbine was obtained using Logan plot with arterial plasma input. Because alpha-2 adrenoceptors are distributed throughout the brain, the estimation of the BPND is complicated by the absence of an anatomic region of no displaceable binding. We used the Inhibition plot to acquire the reference volume, VND, from which we calculated the BPND. Acute pharmacological challenge with amphetamine induced a significant decline of [(11)C]yohimbine BPND of ~38% in all volumes of interest. The BPND was greatest in the thalamus and striatum, followed in descending order by, frontal cortex, pons, and cerebellum. The experimental data demonstrate that [(11)C]yohimbine binding is sensitive to a challenge known to increase the extracellular level of noradrenaline, which can benefit future PET investigations of pathologic conditions related to disrupted noradrenergic neurotransmission.

Chromium sorption and Cr(VI) reduction to Cr(III) by grape stalks and yohimbe bark.

In this work, two low cost sorbents, grape stalks and yohimbe bark wastes were used to remove Cr(VI) and Cr(III) from aqueous solutions. Batch experiments were designed to obtain Cr(VI) and Cr(III) sorption data. The mechanism of Cr(III) and Cr(VI) removal and Cr(VI) reduction to Cr(III) by the two vegetable wastes, has been investigated. Fourier transform infrared rays (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis on solid phase were performed to determine the main functional groups that might be involved in metal uptake and to confirm the presence of Cr(III) on the sorbent, respectively. Results put into evidence that both sorbents are able to reduce Cr(VI) to its trivalent form.