Effects of eight-hour naloxone infusions on human subjects

Biol Psychiatry. 1983 Dec;18(12):1375-92.


Twelve normal male volunteers received saline control, low-dose naloxone, and high-dose naloxone infusions during three weekly sessions. The sessions were 16 hr long: 1 hr for predrug assessments, 8 hr during which either naloxone or saline was infused in a double-blind procedure, and a 7-hr postdrug observation period. The 8-hr infusions of naloxone had no effect on experimental ischemic arm pain. In addition, the ischemic arm pain procedure did not significantly increase either plasma levels of cortisol or immunoreactive beta-endorphin, suggesting that the procedure was not stressful. The high-dose naloxone infusion resulted in a slightly aversive mood state and prevented the normal circadian decrease in cortisol levels. Both doses of naloxone increased systolic blood pressure and prevented the normal diurnal increase in temperature. The 8-hr infusions of naloxone did not result in changes in pain, mood, or physiological indices beyond what was present within a few hours after starting the infusion.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Affect / drug effects*
  • Analgesics*
  • Attention / drug effects
  • Cardiovascular System / drug effects
  • Humans
  • Male
  • Memory / drug effects
  • Naloxone / pharmacology*
  • Naloxone / therapeutic use
  • Pain / prevention & control*
  • Respiration / drug effects
  • Wakefulness / drug effects


  • Analgesics
  • Naloxone