Hypertensive Urgency Associated With Xenadrine EFX Use.

Several supplements and herbal products have been shown to increase catecholamines and subsequently mean arterial pressure and systemic vascular resistance. Since ephedra-containing products have been removed from the market, manufacturers of weight loss herbal supplements must produce ephedra-free formulations. Xenadrine EFX is an ephedra-free weight loss product containing a mixture of caffeine, guarana, and bitter orange (standardized to synephrine). Synephrine has been shown in animals and humans to increase systemic vascular resistance and mean arterial pressure. We present a case of a patient who took Xendarine EFX for 2 weeks prior to her presentation to an emergency department with headaches and hypertensive urgency (blood pressure [BP] 234/130 mm Hg). Her BP was controlled after discontinuation of Xenadrine and initiation a nitroprusside drip and oral clonidine. A Naranjo probability score of 6 indicates the adverse drug reaction was probable. Clinicians should be aware of potential cardiovascular changes in patients on Xenadrine EFX or other synephrine-containing products.