PHARMACOKINETICS OF COCAINE IN PREGNANT AND NONPREGNANT RHESUS-MONKEYS

To determine pharmacokinetic parameters for cocaine in rhesus monkey p lasma, samples were taken over several hours after i.m. administration of cocaine plus a tritiated cocaine tracer. Cocaine and its metabolit es, benzoylecgonine and norcocaine, were isolated via HPLC and quantit ated using liquid scintillation spectrometry. Pregnant subjects were d osed with cocaine at 0.3 (n = 3) or 1.0 (n = 3) mg/kg, whereas nonpreg nant female subjects were dosed with 1.0 mg/kg (n = 3). For the pregna nt subjects, pharmacokinetic studies were conducted on about gestation al day 125 and areas under the concentration versus time curve (AUCs, ng/mL x h) were 64 +/- 26 (+/- SEM) and 143 +/- 12; half-lives (t1/2s, h) were 1.9 +/- 0.6 and 1.1 +/- 0.1 after 0.3 and 1.0 mg/kg i.m., res pectively. For nonpregnant subjects dosed acutely with 1.0 mg/kg, the AUC was 262 +/- 63 and the t1/2 Was 1.4 +/- 0.3. There appear to be fe w differences in the pharmacokinetic parameters of cocaine and benzoyl ecgonine between pregnant and nonpregnant monkeys in this study.