7-Hydroxymitragynine Overdose Causes Cardiac Arrest, Reversed by Naloxone

Why it matters

This case provides the first published clinical evidence of cardiopulmonary arrest following 7-hydroxymitragynine use, directly supporting FDA warnings and proposed scheduling of these semi-synthetic products.

The big picture

The proliferation of high-potency 7-hydroxymitragynine products at gas stations and vape shops — marketed as "legal morphine" — creates life-threatening overdose risk; this case strengthens urgency for regulatory action and naloxone access.

Key findings

• • A 29-year-old man suffered cardiopulmonary arrest and required 10 minutes of CPR; successfully revived with 2 doses of naloxone 4mg IV
• • He had ingested 190mg of 7-hydroxymitragynine (4 tablets) — far above the labeled 12.5mg/serving dose
• • Chemical analysis confirmed products contained 7-hydroxymitragynine 11.7mg, mitragynine 0.45mg, and mitragynine pseudoindoxyl per serving
• • Patient also had blood alcohol of 1,620 mg/L and concurrent gabapentin use, but naloxone reversal points to opioid mechanism

What they say

Case report letter published in Clinical Toxicology (2025) by researchers from University of Florida College of Pharmacy.

Bottom line

This first clinical documentation of cardiac arrest following 7-hydroxymitragynine overdose — reversed by naloxone — confirms its opioid-like lethality potential and the urgent need for regulatory oversight.