ISSN:
1432-2072
Keywords:
Physical dependence
;
Withdrawal syndrome
;
Morphine
;
Buprenorphine
;
Butorphanol
;
Haloperidol
;
Imipramine
;
Naloxone
;
Opioid mixed agonist-antagonist
;
Cynomolgus monkeys
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract This study was conducted to characterize the opiate dependence potential of a number of opiate and non-opiate psychoactive drugs in morphine-dependent cynomolgus monkeys (Macaca fascicularis). In addition, the agonist/antagonist profiles of buprenorphine and butorphanol were directly compared. Six male cynomolgus monkeys were maintained on morphine (3.0 mg/kg, q.i.d.) for 6 months. On evaluation days, monkeys were scored for opiate withdrawal signs 18 h after the last dose of morphine. Single dose suppression studies were conducted by giving subcutaneous injections of morphine (3 or 6 mg/kg), naloxone (0.01, 0.05 or 0.1 mg/kg), buprenorphine (1, 3, 10, 30 or 100 µg/kg), butorphanol (0.01, 0.1, 1.0 or 3.2 mg/kg), haloperidol (0.01, 0.05 or 0.1 mg/kg), imipramine (2, 5 or 10 mg/kg) or saline and measuring the number and frequency of withdrawal signs that appeared over a 2-h period. In a separate precipitation experiment either saline or 0.01 or 0.1 mg/kg butorphanol was administered 2 h after the last maintenance dose of morphine. In the single dose suppression test, morphine completely suppressed most withdrawal signs while naloxone increased the severity of withdrawal. All doses of buprenorphine increased many withdrawal signs such as backward gait, rearing, chafing face, chain biting, vomiting, masturbation, and vocalizations after intimidation. Only a few signs were reduced, but the overall withdrawal scores were not significantly increased. Low doses of butorphanol suppressed some signs while the highest dose almost completely eliminated all withdrawal signs. Butorphanol also failed to precipitate opiate withdrawal, and actually reversed the signs present in the saline-treated monkeys. Imipramine and haloperidol had little effect on the morphine withdrawal syndrome. These data suggest buprenorphine exerts only opioid antagonistic activity and butorphanol exerts only opioid agonistic activity over a wide range of doses studied in morphine-dependent cynomolgus monkeys.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02247468
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