Diagnosis and Treatment of Presumed Naltrexone-XR-precipitated Opioid Withdrawal in a Patient Chronically Treated With Buprenorphine-XR: A Case Report.

Naltrexone, buprenorphine, and methadone are Food and Drug Administration-approved medications for the treatment of opioid use disorder in the United States. Naltrexone, an opioid antagonist, can precipitate opioid withdrawal if administered too quickly after the use of full or partial opioid agonists for those with either dependence or use disorder. We describe a case of severe precipitated opioid withdrawal syndrome after reported buprenorphine extended-release (XR) administration, despite the patient having been stable on buprenorphine-XR for several years, with no missed doses or recent opioid use. Naltrexone levels were sent and helped to diagnose suspected inadvertent naltrexone-XR administration in this patient, which was likely the etiology of his precipitated opioid withdrawal syndrome. We suggest the use of high-dose buprenorphine, as well as adjunctive medications including benzodiazepines, as a treatment strategy for naltrexone-XR precipitated withdrawal in the setting of chronic buprenorphine-XR treatment.