Psychomotor, respiratory and neuroendocrinological effects of nalbuphine and haloperidol, alone and in combination, in healthy subjects

Br J Clin Pharmacol. 1988 Jul;26(1):79-87. doi: 10.1111/j.1365-2125.1988.tb03367.x.


1. Actions and interactions on performance and respiration of single intramuscular doses of 0.15 mg kg-1 nalbuphine and oral haloperidol twice daily for 2 days were studied double-blind and cross-over in 12 healthy volunteers. 2. Objective measurements of performance (choice reaction, tracking, attention, flicker fusion, Maddox wing, digit symbol substitution) and respiratory function (minute volume, end-tidal carbon dioxide), and subjective assessments on visual analogue scales were done at baseline and 1 h, 2.5 h and 4 h after the injection of nalbuphine. Plasma concentrations of nalbuphine were estimated by radioreceptor ([3H]-dihydromorphine) assay, and those of prolactin and growth hormone by radioimmunoassay. 3. Nalbuphine affected digit substitution, reaction time, extraocular muscle balance and flicker recognition, and depressed respiration most clearly 1 and 2.5 h post injection. Motor skills were impaired only briefly. Haloperidol alone proved inert on performance but enhanced the decremental effects of nalbuphine on digit substitution and exophoria at 1 h. It did not interact with nalbuphine on the ventilatory function. 4. Plasma concentrations of nalbuphine expressed as morphine equivalents ranged from 5 to 52 ng ml-1, indicating considerable mu-opiate affinity. Treatment with haloperidol increased plasma prolactin moderately whilst nalbuphine raised it markedly 1 and 2.5 h post injection. Nalbuphine elevated plasma growth hormone at 1 h post injection only.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Clinical Trials as Topic
  • Double-Blind Method
  • Drug Interactions
  • Female
  • Haloperidol / adverse effects
  • Haloperidol / pharmacokinetics
  • Haloperidol / pharmacology*
  • Humans
  • Male
  • Morphinans / pharmacology*
  • Nalbuphine / adverse effects
  • Nalbuphine / pharmacokinetics
  • Nalbuphine / pharmacology*
  • Neurosecretory Systems / drug effects*
  • Psychomotor Performance / drug effects*
  • Random Allocation
  • Respiration / drug effects*
  • Respiratory Function Tests


  • Morphinans
  • Haloperidol
  • Nalbuphine