University of Maryland Emergency Medicine: Kratom Causes Dose-Dependent Effects Requiring Clinical Recognition

Why it matters

Emergency medicine clinicians need practical guidance to recognize and treat kratom toxicity in the ED, as cases are rising sharply. Understanding the dose-dependent nature of kratom effects and available treatment options—including naloxone for respiratory depression and supportive care—is critical for patient safety.

The big picture

Kratom use has increased markedly in recent years, particularly in the United States. The plant contains psychoactive alkaloids (mitragynine and 7-hydroxymitragynine) that produce different effects depending on dose: stimulant effects at lower doses and opioid-like effects at higher doses. Emergency departments are seeing more kratom exposures, including cases requiring naloxone and benzodiazepines for management.

Key findings

• Clinical effects are dose-dependent: stimulant effects (alertness, energy) at lower doses; opioid effects (pain relief, sedation) at higher doses; Mitragynine and 7-hydroxymitragynine have partial agonist effects at mu-opioid receptors with potency similar to codeine; Reported overdose presentations include mixed opioid-like symptoms (CNS depression) and sympathomimetic/serotonin syndrome (hypertension, tachycardia, seizures); Concentrated 7-OH products are more potent than morphine and can cause respiratory depression responsive to naloxone; Urine drug screens do not detect kratom.

What they say

Kratom is an herbal extract from the leaves of trees of the Mitragyna speciosa native to Southeast Asia, containing a complex mixture of psychoactive ingredients with effects at multiple receptors (mu, serotonin, dopamine, and alpha-adrenergic). — University of Maryland Emergency Medicine Educational Pearl, 2026

Bottom line

Emergency clinicians should recognize kratom's dose-dependent dual pharmacology (stimulant/opioid effects), maintain high suspicion for kratom involvement in unexplained toxidromes, and have naloxone available for concentrated 7-OH products.