The Tennessee Health Alert Network (TNHAN), a notification system for the Tennessee Department of Health, recently sent an email alert regarding medetomidine as an adulterant currently in illicit opioid drug supply in Tennessee (1). The alert highlights the severity of the withdrawal from medetomidine. A few key distinctive features:
- Onset of withdrawal from medetomidine may start within 4-6 hours of the last use
- Severe, intractable nausea and vomiting that is not responsive to ondansetron may serve as a clue
- Hypertension may be severe and persistent, despite aggressive therapy.
- Fluctuating hypoactive encephalopathy may occur and is typically not recognized to be a withdrawal syndrome (and could also signal posterior reversible encephalopathy syndrome due to a hypertensive emergency)
- Symptoms have minimal response to GABA or opioid agonists
The Tennessee Poison Center posted a Question of the Week [Who is (another) new kid on the block that is being mixed in with illicit opioids, posted May 2, 2025] about emergence of medetomidine as an adulterant. Medetomidine is racemic mixture of levomedetomidine and dexmedetomidine, with the dexmedetomidine being the more pharmacologically active isomer. Medetomidine is a more potent alpha 2 agonist than clonidine. As a result, the withdrawal from chronic medetomidine use can be severe.
A key challenge is that most of these patients have opioid use disorder and may interpret their symptoms to be opioid withdrawal.
Management of these patients starts with recognizing medetomidine withdrawal as a either a contributor or primary cause of the patient’s symptoms. A recent publication in Annals of Emergency Medicine provides some guidance for treatment (2). In summary, these patients require aggressive use of oral and transdermal alpha2 agonists, with escalation to parenteral dexmedetomidine in severe cases.
Saralyn Williams, MD
References:
1. Tennessee Department of Health. Medetomidine in TN street drug supply—Health Alert. Tennessee Health Alert Network (TNHAN). June 26 2026. https://tnhan.tn.gov
2. Lynch MJ, Pizon AF, Yealy DM. Emergence of medetomidine in the illicit drug supply: Implications for emergency care and withdrawal management. Ann Emerg Med. 2026;87: 709-716.
Tennessee Poison Center Note: Unfortunately, due to a software issue, we had difficulty distributing the Question of the Week the past few months but are now back up and running. It is the end of the academic year and if you or you know anyone who would like to stay on the distribution list, please email Quynh-Thu Musick, PharmD, CSPI at q.musick@vumc.org. Thank you for your readership and good luck on your next adventure.
Rebecca Bruccoleri, MD, Medical Director, Tennessee Poison Center