Comparing the subjective, psychomotor, and physiological effects of intravenous hydromorphone and morphine in healthy volunteers.
BACKGROUND
The psychopharmacological profile of hydromorphone, an opioid that has been used extensively for many years for post-operative pain management, has not been adequately characterized in non-drug abusers.


OBJECTIVE
To characterize the subjective, psychomotor, and physiological effects of a range of single doses of hydromorphone in non-drug-abusing volunteers and to compare the effects of hydromorphone with that of morphine, a benchmark mu opioid agonist.


METHODS
Subjects in a six-session study were injected in an upper extremity vein with 0, 0.33, 0.65, 1.3 mg/70 kg hydromorphone, and 5 and 10 mg/70 kg morphine, using a randomized, double-blind, crossover design.


RESULTS
Hydromorphone increased scores on the pentobarbital-chlorpromazine-alcohol group and lysergic acid diethylamide scales and decreased scores on the benzedrine group scale of the Addiction Research Center Inventory, increased adjective checklist ratings of ("dry mouth", "flushing", and "nodding", and increased visual analog scale ratings indicative of both pleasant (e.g., drug liking) and unpleasant (e.g., "feel bad") effects. The subjective effects of morphine at putatively equianalgesic doses to those of hydromorphone were similar to those of hydromorphone, but in some cases of lesser magnitude. Psychomotor impairment was modest with hydromorphone and absent with morphine. Both opioids produced dose-dependent decreases in pupil size. A relative potency analysis indicated that hydromorphone was 10 times as potent as morphine (1 mg hydromorphone=10 mg morphine).


CONCLUSIONS
The results of this study demonstrate that 0.33-1.3 mg hydromorphone had orderly, dose-related effects on subjective, psychomotor, and physiological variables, and similar effects to those of a benchmark mu opioid agonist, morphine.
Hill
J L
JL
Department of Anesthesia and Critical Care/MC4028, University of Chicago, IL 60637, USA.
Zacny
J P
JP
D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D004091:Hydromorphone / Q000008:administration & dosage / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D010147:Pain Measurement; D011597:Psychomotor Performance / Q000187:drug effects*; D015656:Respiratory Mechanics / Q000187:drug effects; D019966:Substance-Related Disorders / Q000523:psychology; D011795:Surveys and Questionnaires
D000701:Analgesics, Opioid; D009020:Morphine; D004091:Hydromorphone