Precipitated withdrawal during maintenance opioid blockade with extended release naltrexone

Area of Science:

• Pharmacology
• Addiction Medicine
• Adolescent Psychiatry

Background:

• Extended-release injectable naltrexone is increasingly used for opioid dependence treatment.
• Naltrexone blocks opioid receptors, reducing cravings and relapse.
• Adolescent use of this medication is gaining attention.

Observation:

• A 17-year-old female experienced precipitated withdrawal after her third monthly dose of extended-release naltrexone (Vivitrol).
• This occurred several days after using oxycodone, despite mild intoxication.
• The withdrawal was severe and unexpected given the timeline.

Findings:

• Precipitated withdrawal can occur in adolescents treated with extended-release naltrexone.
• Opioid blockade may diminish as naltrexone levels decrease near the end of the dosing interval.
• This can lead to vulnerability to withdrawal if opioids are used during this period.

Implications:

• Clinical management of extended-release naltrexone in adolescents requires careful consideration of dosing intervals.
• Dosing strategies may need adjustment to mitigate risks of precipitated withdrawal.
• Further research is needed to understand naltrexone pharmacokinetics and pharmacodynamics in adolescents.