title: Psychomotor, respiratory and neuroendocrinological effects of nalbuphine and haloperidol, alone and in combination, in healthy subjects.
abstract: 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.
authors.affiliation: Department of Pharmacology and Toxicology, University of Helsinki, Finland.
authors.forename: U
authors.initials: U
authors.lastname: Saarialho-Kere
mesh_terms: D000328:Adult; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D004347:Drug Interactions; D005260:Female; D006220:Haloperidol / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009019:Morphinans / Q000494:pharmacology*; D009266:Nalbuphine / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology*; D009490:Neurosecretory Systems / Q000187:drug effects*; D011597:Psychomotor Performance / Q000187:drug effects*; D011897:Random Allocation; D012119:Respiration / Q000187:drug effects*; D012129:Respiratory Function Tests
chemical_list: D009019:Morphinans; D006220:Haloperidol; D009266:Nalbuphine