PHARMACOKINETICS OF GLYCOPYRROLATE IN CHILDREN

Study Objective: To investigate the pharmacokinetics of glycopyrrolate in children. Design: Open study with three parallel groups. Setting: Pediatric surgery department at a university hospital. Patients: 26 he althy ASA physical status I children undergoing minor surgery. Interve ntions: Patients were assigned to 1 of 3 groups: under 1 year of age ( Group 1, n = 8), between 1 and 3 years of age (Croup 2, n = 7), and ov er 3 years of age (Group 3, n = 11). Glycopyrrolate 5 mu g/kg was give n as a single intravenous (IV) injection before induction of general a nesthesia. Blood samples (for determination of drug concentrations in plasma) were collected via venous cannula inserted into the contralate ral antecubital vein. Measurements and Main Results: ECG was observed continuously, blood pressure was measured with an automatic noninvasiv e device, and blood samples were taken just before and at 2, 4, 6, 10, 15, 30, 60, 120, 180, 240, 360, and 480 minutes after injection. of g lycopyrrolate. Glycopyrrolate concentrations in plasma were determined with a radioreceptor assay. The only significant difference in the ph armacokinetic parameters was the shortened elimination half-life inpat ients between 1 and 3 years of age. Glycopyrrolate 5 mu g/kg IV did no t cause any significant alterations in heart rate. Conclusions: There were no significant changes in the distribution volume or clearance of glycopyrrolate in children of different ages. The shortened eliminati on half-life in children between 1 and 3 years of age is of minor clin ical importance.