The rate of substance use-related ED visits is rising nationally. This includes opioid use disorders, intravenous drug use-related complications, and opioid withdrawal. Opioid withdrawal has not historically been emphasized in emergency physician training, but this clinical entity is becoming a more common presentation in emergency departments. Its clinical manifestations may include nausea, vomiting, abdominal cramping, agitation, anxiety, diarrhea, rhinorrhea, dysphoria, myalgias, tremors, yawning, and piloerection. The onset of withdrawal symptoms varies depending on the half-life of the opioid used and may range anywhere from 12 to 30 hours after the last opioid use. Withdrawal, while very uncomfortable, is rarely life-threatening itself. For patients presenting to the ED with acute opioid withdrawal, it is recommended to use emergency department-administered buprenorphine or methadone over nonopioid-based strategies. These options are more effective than alternative modalities such as the combination of alpha-2-adrenergic agonists (e.g., clonidine, lofexidine) and antiemetics (e.g., promethazine). Of these two options, buprenorphine is preferred over methadone. Buprenorphine is a synthetic derivative of thebaine, an opioid alkaloid that is more potent and longer-lasting than morphine. It primarily acts on mu-opioid receptors as a partial agonist and has a half-life of 24 hours or longer. It is currently a Schedule III drug in the US. Buprenorphine is preferred over methadone for acute withdrawal due to the theoretical risk of opioid toxicity in patients who receive methadone in the ED and then subsequently use opioids after discharge. Methadone is a synthetic opioid with a long duration of action (i.e., hours to days, beyond the ED visit). This is in contrast to buprenorphine, which—because of its partial agonist activity and shorter duration of action—creates a ceiling on respiratory depression.
Clonidine (B) is falling out of favor as the most effective means of treating acute opioid withdrawal in the ED compared to buprenorphine or methadone. Methadone (C) is still recommended over nonopioid-based management strategies, but it carries the risk of respiratory depression after ED discharge for those who subsequently use opioids. Administering oxycodone (D) to this patient who is attempting to wean herself from opioids does not represent the best management and may further contribute to her opioid use disorder.