Precipitated withdrawal during maintenance opioid blockade with extended release naltrexone.

Background There has been increasing interest in the use of extended release injectable naltrexone for the treatment of opioid dependence. Case description We report a case of precipitated withdrawal in a 17-year-old adolescent female receiving extended release naltrexone (Vivitrol) for opioid dependence, following her third serial monthly dose of the medication, several days after using oxycodone with mild intoxication. Conclusions This case suggests that, in some circumstances, the opioid blockade may be overcome when naltrexone levels drop towards the end of the dosing interval, producing vulnerability to subsequent naltrexone-induced withdrawal. This may provide cautionary guidance for clinical management and dosing strategies.