Kratom: An Emerging Drug of Abuse

Kratom seems to have dose-dependent effects. At low doses (1-5 g of raw crushed leaves), kratom abusers often report a mild energizing effect, thought to be secondary to the stimulant properties of kratom’s multiple alkaloids. Users have reported mild euphoria and highs similar to those of the abuse of methylphenidate or modafinil.^2,9,10 Also similar to abuse of those substances, users have reported anxiety, irritability, and aggressiveness as a result of the stimulant-like effects.

At moderate-to-high doses (5-15 g of raw crushed leaves), it is believed that the mu-opiate receptor agonism overtakes the stimulant effects, leading to the euphoria, relaxation, and analgesia seen with conventional opioid use and abuse.^2,10 In light of the drug’s substantial binding and agonism of all opioid receptors, constipation and itching also are seen.² As such, if an individual is intoxicated, he or she should be managed with supportive and symptomatic care and continuous monitoring of heart rate, blood pressure, respiratory rate, and oxygen saturation.^2,10 Kratom intoxication can precipitate psychotic episodes similar to those caused by opiate intoxication, so monitoring for agitation or psychotic behaviors is also indicated.^9,10

The medical management of a patient with an acute kratom overdose (typically requiring ingestion of >15 g of crushed leaves) begins with addressing airway support, breathing, and circulation along with continuous vital sign monitoring and laboratory testing, including POC glucose testing, complete blood count, electrolytes, lactate, venous blood gas, and measurable drug levels (ethanol, acetaminophen, tricyclic antidepressants, as indicated).¹¹ If it is determined that kratom was the intoxicant, the greatest concern of death is similar to that of opioid overdose: respiratory depression. Although there are no large-scale human studies demonstrating efficacy, multiple authors suggest the use of naloxone in kratom-related hypoventilation.^9,10

The development of dependence on kratom and its subsequent withdrawal phenomena are thought to be similar to that of opioids, in light of its strong mu agonism.^2,5,9,10 Indeed, kratom has a long history of being used by opioid-dependent patients as an attempt to quit drug abuse or stave off debilitating withdrawal symptoms when they are unable to acquire their substance of choice.^2,5-10 As such, withdrawal and the treatment thereof will also mimic that of opioid withdrawal.

The kratom-dependent individual will often present with rhinorrhea, lacrimation, dry mouth, hostility, aggression, and emotional lability similar to the case study described earlier.^2,9,10 Kratom withdrawal, much like intoxication, also may precipitate or worsen psychotic symptoms, and monitoring is necessary throughout the detoxification process.^2,5,10 Withdrawal management should proceed along ambulatory clinic or hospital opioid withdrawal protocols that include step-down administration of opioids or with nonopioid medications for symptomatic relief, including muscle relaxants, alpha-2 agonists, and antidiarrheal agents.^5,9,10

Kratom Toxicity

A review of the available medical literature has demonstrated a number of toxic effects with kratom abuse, either as the sole agent or in concert with prescribed medications, recreational coingestants, or as a result of manufacturer’s adulteration with other chemicals or drugs. Of particular interest to EPs are manic or psychotic episode precipitation, seizure, hypothyroidism, intrahepatic cholestatic injury, and even sudden cardiac death.^2,3,5-10 In addition to the basic history, physical, and laboratory examination, the workup of patients identified as kratom users should include the following:

• Fastidious medication reconciliation with drug-interaction check;
• Exhaustive substance abuse history;
• Identification of the brand name and source of kratom purchased, to determine whether there are advertised coingestants or reports of adulteration;
• Electrocardiogram;
• Thyroid function testing;
• Hepatic function testing; and
• Comprehensive neurological and mental status examinations.

In chronic users of kratom, a number of effects have been seen whose etiologies have not yet been determined. These effects include depression, anxiety, tremulousness, weight loss, and psychosis.^3-7 Additionally, a study by Kittirattanapaiboon et al¹² correlated drug use by those with concurrent mental health disorders (in particular, kratom, which was used in 59% of the ≥14,000 individuals included in the study sample) with statistically significant higher suicide risk.

Detection

Because kratom is a relatively new compound in the United States, medical and forensic laboratories are only now implementing kratom detection protocols. Many laboratories now use high-performance liquid chromatography to analyze for mitragynine, 7-hydroxymitragynine, and two metabolites of mitragynine in urine.⁷ Le et al¹³ were able to detect mitragynine in the urine in levels as low as 1 ng/mL, which is clinically useful as mitragynine has a half-life determined in animal studies to be 3.85 hours. Similar detection limits for mitragynine and 7-hydroxymitragynine are used only at the Naval Medical Center Portsmouth in Virginia; however, kratom was not detected in the case study patient’s urine because a urine test was not done until hospital day 5.