Kratom Drug Classification
Kratom is classified as an atypical opioid agonist with both opioid-like and stimulant properties, acting primarily on mu-, delta-, and kappa-opioid receptors, as well as adrenergic, serotonergic, and dopaminergic pathways. 1, 2, 3
Pharmacological Profile
Kratom (Mitragyna speciosa) contains over 40 alkaloids, with mitragynine and 7-hydroxymitragynine (7-OH-MG) being the main psychoactive compounds that function as atypical opioid receptor agonists 2. Unlike traditional opioids, kratom exhibits:
- Dual mechanism: Opioid receptor agonism (mu, delta, kappa receptors) combined with effects on alpha-2 adrenergic receptors, 5-HT2A serotonergic receptors, and dopaminergic pathways 2, 3, 4
- Dose-dependent effects: Stimulant properties at lower doses and opioid-like sedative effects at higher doses 5
- Complex polypharmacy: More accurately characterized as a substance with diverse pharmacology rather than a simple opioid 6
Clinical Characteristics
The substance demonstrates classic opioid-like properties including:
- Physical and psychological dependence potential 2, 7
- Withdrawal syndrome when taking more than 5-15 grams per day 1
- Tolerance development with chronic use 7
- Analgesic and euphoric effects similar to traditional opioids 3
Animal studies suggest kratom may be more potent than morphine 3, though it appears to carry lower risk of respiratory depression compared to traditional opioid medications 2.
Regulatory Status and Safety Concerns
The FDA warns against kratom use, and SPAQI (Society for Perioperative Assessment and Quality Improvement) explicitly does not recommend its use 1. The guideline states it should be discontinued, not merely held perioperatively.
Serious Adverse Effects Include:
- Neurologic effects including seizures with chronic use 1
- Hepatotoxicity and liver injury 8
- Cardiotoxicity 8
- Hallucinations, delusions, and depression 3
- Deaths have been reported, often in the context of polysubstance use 5, 8
Important Clinical Pitfall
Kratom is often marketed as a "natural" or "safe" dietary supplement, but this characterization is misleading 6, 2. Despite being botanically related to the coffee tree family, its pharmacological profile is dominated by opioid receptor activity, making it functionally an opioid agonist with abuse potential 3, 4. The substance remains unscheduled federally despite DEA attempts to classify it as Schedule I in 2016 2.
Buprenorphine-naloxone has shown efficacy in treating kratom dependence complicated by chronic pain and depression 7, supporting its classification as an opioid-class substance from a treatment perspective.