Hospitals must develop new protocols as overdose crisis enters dangerous new phase with ‘rhino tranq’

After claiming more than 500,000 American lives over the course of two decades, the overdose crisis has entered an even deadlier phase.

In Philadelphia-area intensive care units, doctors are now facing an unprecedented challenge that’s upending decades of medical protocols. A patient experiencing drug withdrawal now requires advanced critical care intervention — their blood pressure dangerously high, vomiting uncontrollable, mental status altered, and heart rate plummeting.

Across the city, ICUs are adapting to a new reality: medetomidine, dubbed “rhino tranq” on the streets.

Medetomidine — a powerful animal tranquilizer up to 200 times more potent than its predecessor xylazine — has infiltrated the drug supply and silently become the dominant additive in Philadelphia’s fentanyl supply.

According to the Philadelphia Medical Examiner’s Office, it is now present in 87% of the city’s fentanyl samples, transforming what was routine withdrawal management into critical care emergencies in hospitals.

The emergence of medetomidine marks a dangerous new phase in the overdose crisis. First detected in Maryland in July 2022, it has now spread to major cities including Philadelphia. In May 2024, Philadelphia documented 160 overdoses in just four days, with medetomidine detected in 46 overdose deaths.

Six months later, in November 2024, the city saw the prevalence of medetomidine surpass the prevalence of xylazine in the drug supply for the first time.

And just last month, in December 2024, the Philadelphia Department of Health issued an alert about the rising drug-related morbidity and mortality from medetomidine.

The implications cannot be overstated. In comparison to xylazine, medetomidine produces withdrawal symptoms so severe they can be life-threatening. Patients experience intractable vomiting, hypertensive emergencies resistant to standard treatments, and complex cardiac presentations.

Nearly one in five recent fentanyl-related deaths in Philadelphia now involve medetomidine, with users remaining sedated for at least three hours after exposure.

Our health care system is struggling to adapt. Standard withdrawal protocols have become insufficient, with traditional assessment tools proving inadequate for these complex cases. Emergency departments and inpatient units find themselves utilizing patient beds typically reserved for intensive care, and ICUs are facing increasing strain in allocating resources to these patients.

The situation is also complicated because naloxone, the opioid overdose reversal agent, has no effect on medetomidine. Without systemic changes, we risk overwhelming our ICUs while failing to adequately treat patients.

To address this evolving crisis, we need a three-pronged approach.

First, we must dramatically expand rapid access to treatments for addiction and harm reduction resources. This means implementing 24/7 buprenorphine or methadone initiation in emergency departments, deploying mobile treatment units to reach people where they are, and increasing the distribution of key resources such as naloxone and safe syringe exchange options. The evidence is clear — early intervention with appropriate medication saves lives.

Second, hospitals must develop specialized protocols and guidance for managing severe withdrawal. This requires additional training for health care providers, new guidelines that account for medetomidine’s unique challenges, and potentially new staffing models to support more intensive monitoring outside the ICU.

Just like many hospital departments adapted their protocols during the pandemic to provide respiratory support outside the ICU to accommodate the large influx of patients, other departments must also enhance their capacity to monitor patients outside the ICU who are experiencing withdrawal.

Third, we need increased surveillance of the drug supply. A coordinated public health response that includes real-time tracking of medetomidine prevalence and rapid communication channels between health care providers and public health officials would enable early detection of changes in the drug supply, which can provide key insights into dominant drug trends, allow providers to deliver more tailored care, and encourage hospitals to allocate their resources more effectively — all of which will ultimately save lives.

The emergence of medetomidine represents a critical moment in the ongoing overdose crisis. Without swift intervention, more lives will be lost, and our health care systems will continue to be overwhelmed.

State and federal support is essential to implement these solutions, but we cannot afford to wait. Philadelphia’s experience should serve as a warning to other cities: the next phase of the overdose crisis is here, and it demands an immediate and comprehensive response.

Kevan Shah is the founder and executive director of End Overdose Together. He is an MD candidate at Cooper Medical School of Rowan University. Suhanee Mitragotri is an undergraduate student at Harvard University and the co-founder of the Naloxone Education Initiative in Massachusetts.