Articles: narcotic-antagonists.
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Pharmacol. Biochem. Behav. · Apr 2003
Comparative StudyAgonist/antagonist properties of nalbuphine, butorphanol and (-)-pentazocine in male vs. female rats.
To determine whether sex differences in the effects of mixed-action opioids could be due to differential activity at mu or kappa receptors, agonist/antagonist properties of nalbuphine, butorphanol and (-)-pentazocine were compared in male vs. female rats using a diuresis test. In water-loaded rats (2-h test), nalbuphine and (-)-pentazocine dose-dependently increased urination similarly in both sexes, whereas butorphanol increased urination more in females than in males on a ml/kg basis. The diuretic effects of all three opioids were at least partially blocked by the kappa receptor-selective antagonist nor-binaltorphimine (nor-BNI, 5 mg/kg) in both sexes. ⋯ The ability of nalbuphine and (-)-pentazocine to block fentanyl-induced antidiuresis was not affected by pretreatment with nor-BNI in either sex. In contrast, the ability of butorphanol to block fentanyl-induced antidiuresis was attenuated by pretreatment with nor-BNI in males but not in females. These results suggest that sex differences in the effects of these mixed-action opioids are primarily due to their greater relative efficacy at the mu receptor in male than in female rats; butorphanol also may have greater efficacy at kappa receptors in females than in males.
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J Subst Abuse Treat · Apr 2003
Randomized Controlled Trial Comparative Study Clinical TrialMethadone versus buprenorphine maintenance for the treatment of heroin-dependent outpatients.
The aim of this study was to assess the efficacy of methadone compared with buprenorphine maintenance therapy in heroin-dependent patients over a treatment period of 18 weeks. Subjects were randomized to receive either methadone or buprenorphine in a comparative double-blind study and consisted of 164 heroin-dependent male patients who met the DSM-IV criteria for heroin dependence and were seeking treatment. The 164 subjects included 41 patients in 1-mg, 41 patients in 3-mg, and 41 patients in 8-mg dosage group of buprenorphine, and also 41 patients in the 30-mg dosage group of methadone. ⋯ Retention in the 8-mg dose group was significantly better than in the 1-mg dose group (p=.00041) and in the 3-mg dose group (p=.045); other comparison (1 mg dose with 3 mg dose) was not significant. Methadone group was significantly better than 1mg buprenorphine dose group (p=.004), but was not significantly different from 3 mg buprenorphine dose group (p=.18) or 8 mg buprenorphine dose group (p=.49). The results support the efficacy of buprenorphine for outpatient treatment of heroin dependence and seem to indicate that the highest dose (8 mg) of buprenorphine was the best of the three doses of buprenorphine, and also support the superiority of 30 mg of methadone compared to 1 mg dose of buprenorphine for Iranian heroin-dependent patients to increase their retention in treatment.