Opiate antagonists and eating behavior in humans: a review.

Animal studies have demonstrated a robust role for the endogenous opioid system in the control of food intake. In humans, selective opioid antagonists such as naloxone, naltrexone, and nalmefene have been shown in some studies to reduce total food intake by up to 30% and to alter food preferences in short-term experimental trials in normal-weight subjects, as well as in obese and bulimic patients. The value of naloxone and naltrexone in the long-term treatment of eating disordered patients, however, must be considered very limited. The published treatment studies do not justify the routine use of naloxone and naltrexone in patients with Prader-Willi syndrome, obesity, bulimia nervosa, or anorexia nervosa because of their unprofitable risk/benefit ratios, although further work, particularly focused on some of the newer antagonists, should be undertaken.