Xylazine / medetomidine ("tranq")

psilodex.org/m/xylazine-medetomidine · data v2026.10.02

Clinical contraindication: Relative; Substantial clinical concern; the literature treats it as a reason for caution or deferral.
Best available evidence: Case reports
Half-life: Not recorded

Named in state rules?

CONot named

ORNot named

NMPending

Cite asPsilodex: xylazine-medetomidine · v2026.10.02

Clinical data and state rules are separate facts. Both are shown; neither is a decision.

01 Interaction with psilocybin

Veterinary alpha-2 sedatives found mostly in illicit fentanyl. They cause deep, prolonged sedation, slow heart rate and low blood pressure that naloxone does not reverse. Medetomidine withdrawal can bring severe hypertension, fast heart rate and vomiting within hours.

Human data with psilocybin: Case reports or surveys only

Evidence types on this record

CRCase reports or online surveys

02 Pharmacology relevant to psilocybin

3 listed · counted on reports

Sedating or CNS depressant: Slows the central nervous system: drowsiness, slower reactions and impaired coordination, and slowed breathing at high doses. Effects add with other sedating substances. Sources [1][2]
Lowers blood pressure or causes orthostasis: Lowers blood pressure, or causes a drop on standing (orthostasis) that can bring dizziness or fainting. Sources [1][2]
Withdrawal or rebound if stopped abruptly: Stopping suddenly can cause withdrawal or a rebound of symptoms. Any change to the dose is the prescriber’s decision. Sources [2][3]

03 State rules

Plain-language summary · official text governs

CO4 CCR 755-1

Not named

No provision names this medication or its class.

Colorado · checked 2026-09-30

OROAR 333-333

Not named

No provision names this medication or its class.

Oregon · checked 2026-09-30

NM7.35.3 NMAC (proposed)

Pending

New Mexico's clinical rules (proposed 7.35.3 NMAC) are not final. No provision naming this medication has been found.

New Mexico · checked 2026-10-02

04 Conditions to ask about

None linked

No condition named in state rules is linked to this medication.

05 Sources

National Institute on Drug Abuse (NIDA), NIH. Research-topic pages (per-entry link). — CNS depressant; breathing, heart rate and blood pressure can slow to dangerously low levels; naloxone does not reverse xylazine
Centers for Disease Control and Prevention. Medetomidine in the U.S. illegal fentanyl supply increasing risk for overdose and severe withdrawal syndrome. Health Alert Network HAN-00527, April 2, 2026. — alpha-2 agonist more potent and longer-acting than xylazine; bradycardia, hypotension, prolonged sedation; withdrawal with tachycardia and severe hypertension peaking 18–36 h
Huo S, London K, Murphy L, et al. Notes from the field: suspected medetomidine withdrawal syndrome among fentanyl-exposed patients — Philadelphia, Pennsylvania, September 2024–January 2025. MMWR 2025;74:266–268. — suspected medetomidine withdrawal syndrome, Philadelphia; 165 patients
US Drug Enforcement Administration. 2025 National Drug Threat Assessment. May 2025. — xylazine veterinary-only; 'rhino tranq' medetomidine 200–300x xylazine potency (pp. 30–32)

Record history

v2026.10.02First published.
2026-10-02Last reviewed against its sources.

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