Effects of nandrolone on acute morphine responses, tolerance and dependence in mice.

Anabolic-androgenic steroid exposure has been proposed to present a risk factor for the misuse of other drugs of abuse. We now examined whether the exposure to the anabolic-androgenic steroid, nandrolone, would affect the acute morphine responses, tolerance and dependence in rodents. For this purpose, mice received nandrolone using pre-exposure (for 14 days before morphine experiments) or co-administration (1 h before each morphine injection) procedures.