Naloxone augments the hypothalamic-pituitary-adrenal axis response to methylphenidate in normal subjects

Six healthy male subjects were studied to assess how naloxone affects the hypothalamic-pituitary-adrenal (HPA) axis response to the stimulant drug, methylphenidate. It was found that the ACTH response to combined naloxone and methylphenidate was significantly greater than the sum of the ACTH responses to naloxone and methylphenidate individually.