Xylazine identified in drug overdose deaths in Maryland, USA

In the January 2019 edition of ToxTidbits, the Maryland Poison Center reports the identification of xylazine in drug overdose deaths. Xylazine is a sedative, muscle relaxant, and analgesic for veterinary use. The pharmacokinetics of xylazine in humans have not been determined. Based on animal studies and case reports, the onset with parenteral xylazine is expected to be within 30 minutes. Although the duration of effects in animals is 4 hours, the duration was 8-72 hours in human case reports. Clinical effects that may occur with xylazine exposures include drowsiness, slurred speech, coma, hyporeflexia, transient hypertension, and tachycardia followed by hypotension and bradycardia, dysrhythmias, respiratory depression, miosis, hyperglycemia, hypothermia. Deaths have been reported.