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Biomedical subjects

M Fischman

Publications and source records attributed to M Fischman.

9 recordsLinked to original sources
PubMedDate not supplied

Kinetics of cocaine in humans after intravenous and intranasal administration.

Cocaine kinetics were studied in four subjects after intravenous and intranasal administration. For intravenous administration cocaine hydrochloride (32 mg) dissolved in physiological saline was injected in 1 ml volume over a 1 min period. Intranasal cocaine was administered as 100 mg powder consisting of an appropriate dose of cocaine hydrochloride (64 and 96 mg) mixed with lactose powder. Subjects were instructed to inhale the mixture through a 5 cm straw within 1 min. Cocaine kinetics, after intravenous injection, conform to a one-compartment open model with first-order elimination. After intranasal administration, cocaine kinetics conform to a one-compartment model with first-order absorption and first-order elimination. The mean half-life of cocaine for intravenous injection in four subjects was 41.4 +/- 8.2 min (mean +/- S.E.M.) and the range was 19 to 64 min. There were statistically significant differences in the mean area under the concentration-time curve (AUC) following intravenous and intranasal administration. The AUC was dose-dependent and the fraction of the dose absorbed after 64 mg intranasal cocaine was significantly lower than after 96 mg dose (p less than 0.05).

Administration, Intranasal↗
PubMedDate not supplied

Urinary excretion of ecgonine methyl ester, a major metabolite of cocaine in humans.

In this study, cocaine, benzoylecgonine, and ecgonine methyl ester excretion in urine was measured after intravenous and intranasal administration of cocaine at 16, 32, 48, and 96 mg doses to healthy cocaine users. Ecgonine methyl ester and cocaine were analyzed by gas chromatography/mass spectrometry. Benzoylecgonine was measured by immunoassay (EMIT) and liquid chromatography. Urinary ecgonine methyl ester accounted for 26 to 60% of the cocaine dose. Ecgonine methyl ester had an elimination halflife of 4.2 hr, compared with 5.1 hr for benzoylecgonine. These results indicate that ecgonine methyl ester accounts for most of the previously unidentified urinary metabolic products of cocaine. The time course of ecgonine methyl ester excretion is such that its detection can substitute for benzoylecgonine detection as a marker of cocaine use.

Adult↗