Expected opioid-like side effects that may occur with kratom include:
- Dry mouth
- Increased urination
- Loss of appetite
Case reports describe the following adverse effects from kratom: addiction, withdrawal, hypothyroidism, and liver injury, aching of muscles and bones and jerky limb movements.
Kratom addiction and chronic use has led to cases of psychosis with hallucinations, delusion, and confusion. High-dose use may lead to fast heart rate (tachycardia) and low blood pressure (hypotension). Tremor, anorexia and weight loss are other possible side effects with long-term use.
Seizures have been reported when kratom was combined with modafinil in at least one case report. The DEA has also reported seizure adverse events with recreations kratom use.
A case series from Kronstad, et al. described a fatal drug interaction with kratom. A substance, dubbed “Krypton” – a mixture of mitragynine and a metabolite of tramadol – was found post-mortem in nine people in Sweden over a one year period. Tramadol, an opioid-like prescription pain drug, was most likely added to kratom to boost its narcotic-like effect.
In November 2017 and February 2018, the FDA issued a public health advisory about deadly risks associated with kratom. There have been 44 reports of Kratom-related deaths, sometimes used in combination with other illicit drugs, prescription drugs, or over-the-counter agents such as loperamide (Imodium).
As with many herbal alternatives, designer drugs, or illicit products sold on the Internet, the possibility exists that kratom may also be contaminated with illegal drugs, black market prescription medications, or even poisonous products. Consumers should avoid buying unknown drug products from the Internet. When combined with other drugs — recreational, prescription, or alcohol — the effects of kratom are unknown and may be dangerous.