British journal of clinical pharmacology
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1. The metabolism of morphine was studied in 12 children and nine premature neonates on a continuous infusion of morphine (10-360 micrograms kg-1 h-1). 2. The mean plasma clearance of morphine was significantly higher in children than neonates (25.7 and 4.7 ml min-1 kg-1, respectively) (P less than 0.01). 3. ⋯ All the children and five neonates had detectable concentrations of morphine-6-glucuronide (M6G) in plasma or urine. 4. The M3G/morphine ratios in plasma and urine, and M6G/morphine ratios in urine were significantly higher in children than neonates (P less than 0.01), suggesting that morphine glucuronidation capacity is enhanced after the neonatal period. 5. There was no difference in the M3G/M6G ratio in children and neonates, indicating a parallel development of both glucuronidation pathways.
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Br J Clin Pharmacol · Nov 1989
Randomized Controlled Trial Clinical TrialCNS-related subjective symptoms during treatment with beta 1-adrenoceptor antagonists (atenolol, metoprolol): two double-blind placebo controlled studies.
1. Whilst a number of studies have investigated whether metoprolol and atenolol, the most widely used beta 1-adrenoceptor antagonists, differ with regard to CNS-related subjective symptoms, few placebo-controlled studies using standardised questionnaires have been performed. 2. In the present report, the findings of two randomised, double-blind, cross-over studies in healthy volunteers are presented. ⋯ No significant differences were found in relation to Type A behaviour and beta-adrenoceptor blockade. The number of subjects with Type A personality was, however, low. 5. The results of the studies indicate that the subjective symptoms of the beta 1-adrenoceptor blockers are mild, and that the effects appear consistently with the recognised pharmacokinetic profiles of the two drugs.