Acute altered mental status secondary to naltrexone-induced opiate withdrawal

Altered Mental Status (AMS) is a common presentation seen in the emergency room and hospital wards. As such, it is essential that physicians have a systematic approach to determine the underlying cause of AMS. Given the increase in opioid usage, opioid withdrawal is an important differential diagnosis of AMS. Opioid withdrawal may be precipated by the cessation of opioid use or the use of an opioid antagonist. Unfortunately, the later may not be immediately considered by the physician to be a cause of a patient's AMS. This case illustrates that the use of an opioid antagonist, such as naltrexone, may precipitate acute AMS in those who also take chronic opioid prescription analgesics and highlights the importance of a thorough pharmacological review before initiating new perscriptions, in both the inpatient and outpatient setting.