Use unexplained ulcers or naloxone-refractory overdose to think about xylazine exposure. Keep counterfeit pills and fentanyl contamination high on the differential when the presentation is severe or atypical.

Naloxone does not reverse xylazine, so overdose resuscitation can be more difficult; Xylazine is a veterinary alpha-2 agonist sedative; In the illicit supply, it is often mixed with fentanyl and can cause treatment-resistant bradycardia and hypotension; Xylazine ulcers are slow to heal and may occur away from injection sites; Counterfeit opioid pills can contain unpredictable and lethal fentanyl doses