Case Presentation: A 34-year-old female with a history of alcohol use disorder presented with severe withdrawal symptoms approximately one hour after receiving her first dose of naltrexone, which was prescribed for the management of alcohol cravings. The symptoms included excessive yawning, anxiety, irritability, tachycardia, generalized muscle cramps, and discomfort. Laboratory investigations revealed a blood alcohol level of 324 mg/dL and a negative toxicology screen. Despite treatment with benzodiazepines, her symptoms persisted without significant improvement.Further comprehensive history-taking revealed that the patient had been consuming 12 kratom capsules daily to self-manage symptoms of opioid withdrawal and chronic pain. On physical examination, she exhibited mydriasis and hyperreflexia, findings consistent with opioid withdrawal. Initiation of sublingual buprenorphine/naloxone resulted in marked improvement and resolution of her withdrawal symptoms.
Discussion: Kratom (Mitragyna speciosa) exerts dual stimulant and opioid-like effects through its active alkaloids, mitragynine, and 7-hydroxymitragynine by acting on mu-opioid receptors, especially at high doses. Naltrexone, a mu-opioid receptor antagonist, displaces kratom’s alkaloids from opioid receptors, precipitating acute withdrawal. This interaction likely caused the severe symptoms observed in this patient. Buprenorphine/naloxone effectively managed her symptoms by leveraging buprenorphine’s partial agonist activity at mu-opioid receptors, which alleviates withdrawal, and naloxone’s role in deterring misuse.Approximately 1-2% of U.S. adults use kratom for pain or opioid dependence, yet standard drug screens do not detect it, complicating diagnosis.
Conclusions: Kratom is a herbal supplement that is not FDA-approved and has the potential for addiction. Concurrent use with naltrexone can precipitate kratom withdrawal, which resembles opioid withdrawal. Hospital medicine Physicians need to be aware of kratom use and its pharmacological interactions, especially before prescribing naltrexone and in managing polysubstance use disorders in hospital medicine, to prevent adverse effects and ensure optimal care amid increasing substance use diversity.