Clinical pharmacology and therapeutics
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Clin. Pharmacol. Ther. · Apr 1996
Randomized Controlled Trial Clinical TrialMethylnaltrexone prevents morphine-induced delay in oral-cecal transit time without affecting analgesia: a double-blind randomized placebo-controlled trial.
Methylnaltrexone is a quaternary opioid antagonist with limited ability to cross the blood-brain barrier and the potential to antagonize the peripherally mediated effects of opioids. The effectiveness of methylnaltrexone in preventing morphine-induced changes in gastrointestinal motility and transit without affecting analgesia was evaluated in humans. Twelve healthy volunteers were given intravenous placebo, placebo plus 0.05 mg/kg morphine, or 0.45 mg/kg methylnaltrexone plus 0.05 mg/kg morphine. ⋯ Methylnaltrexone did not affect the analgesic effect of morphine on both pain intensity and pain bothersomeness ratings. At a higher dose of morphine (0.1 mg/kg), our preliminary results indicated that 0.45 mg/kg methylnaltrexone also prevented the morphine-induced delay in oral-cecal transit time, with no effect on analgesia. Methylnaltrexone may be a useful adjunct to opioids for the relief of opioid-induced constipation.
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Clin. Pharmacol. Ther. · Mar 1996
Randomized Controlled Trial Comparative Study Clinical TrialComparison of intranasal midazolam and sufentanil premedication in pediatric outpatients.
Intranasally administered midazolam was compared with sufentanil as a premedicant for 60 patients, aged 1/2 to 6 years, undergoing outpatient surgery of 2 hours or less. ⋯ Both intranasal midazolam and sufentanil provide rapid, safe, and effective sedation in small children before anesthesia for ambulatory surgery. Sufentanil provided somewhat better conditions for induction and emergence. Midazolam causes more nasal irritation during instillation, and sufentanil causes more postoperative nausea and vomiting. Both drugs enabled patients to be separated from their parents with a minimum of distress. Patients in the midazolam group were discharged approximately 40 minutes earlier (p <0.005).
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Clin. Pharmacol. Ther. · Jan 1996
Pharmacokinetic-pharmacodynamic relationships of controlled-release oxycodone.
Plasma concentrations of oxycodone, oxymorphone, and noroxycodone were determined after administration of 20 mg oral controlled-release oxycodone tablets to four subject groups: young (aged 21 to 45 years) men, elderly (aged 65 to 79 years) men, young women, and elderly women. Area under the oxycodone and noroxycodone concentration-time curve (AUC) values were comparable among the four groups. Compared with oxycodone, the oxymorphone AUC values were small, with significant differences between subject groups. ⋯ The two groups with the highest oxycodone AUC values (young and elderly women) had the lowest oxymorphone AUC values and the greatest drug effect AUC values. The two groups with the lowest oxycodone AUC values (young and elderly men) had the highest oxymorphone AUC values and the lowest drug effect AUC values. These results support oxycodone, and not oxymorphone, as being primarily responsible for pharmacodynamic and analgesic effects.