Medetomidine Objective Withdrawal Scale (MOWS)
Pouya Azar, Jessica Machado, Jane Kim, James Wong, Sahithi Thotakura, Jacky Siu, Anthony Lau, Sarah Haddleton, Keegan Epp, Nick Matthew, Victor Li.
February 6, 2026
Summary
We are seeing cases of medetomidine withdrawal in hospitalized patients; medetomidine is an alpha-2 adrenergic agonist. This syndrome is driven by autonomic hyperactivity and persists despite aggressive treatment of opioid withdrawal and/or benzodiazepine withdrawal. Patients have been known to decompensate quickly and prompt intervention is imperative to prevent escalation of care to higher acuity areas.
A medetomidine withdrawal protocol has been developed to support recognition, scoring, and management using PRN clonidine.
Background
Over the past two years, medetomidine has emerged as a novel adulterant in the illicit fentanyl supply across multiple regions of North America.
As of December 2025, medetomidine has been detected on over 30% of unregulated opioid samples in the province of British Columbia. In Philadelphia approximately 25% of ICU beds are occupied by patients with complications from medetomidine withdrawal. Watch our interview with Dr. Jeanmarie Perrone (UPENN) on how alpha-2 agonists are changing addiction medicine in Philadelphia.
