Naloxone reduces the food intake of normal human volunteers

While there is substantial evidence that the food intake of laboratory animals in suppressed following administration of opiate antagonists, there is less known about the effects of opiate antagonists on human feeding. This study was undertaken to examine the effect of the relatively specific opiate antagonist, naloxone, on the food intake of normal human volunteer subjects. We found that naloxone, given intravenously in single doses of 0.8 and 1.6 mg under double-blind conditions to 12 healthy subjects, caused a dose-related suppression of food intake compared to placebo, maximal at 2.5 h. No effect was observed on subjective ratings of hunger, satiety, mood or arousal, or on total flu id intake. These findings suggest that endogenous opiates may play a role in the regulation of human feeding.