Which alpha-adrenergic blocking agent is used as reversal for xylazine?

Which alpha-adrenergic blocking agent is used as reversal for xylazine?

• A. Tolazoline
• B. Yohimbine
• C. Naloxone
• D. Atipamezole

Answer: (B)

Reversing xylazine relies on blocking its action at the alpha-2 adrenergic receptors. Yohimbine is a competitive alpha-2 adrenergic antagonist, so it binds to those same receptors and prevents xylazine from activating them. By doing this, it quickly reverses the sedative, analgesic, and cardiovascular depressant effects of xylazine, restoring alertness, heart rate, and blood pressure. Historically and in many practice settings, yohimbine has been a go-to reversal for xylazine because of its effectiveness in counteracting those alpha-2–mediated effects.

Tolazoline also blocks alpha receptors but is less selective and can produce more variable cardiovascular responses. Naloxone targets opioid receptors, so it won’t reverse xylazine. Atipamezole is a newer, highly selective alpha-2 antagonist and is widely used today for xylazine reversal, but the option highlighted here reflects the traditional pairing of xylazine with yohimbine.