Pharmacokinetic studies in man with sparteine

Abstract

Plasma levels of sparteine were determined in two groups of 8 patients each of whom received 200 mg of sparteine sulphate (Depasan®) intravenously and orally. A method was developed for the determination of sparteine in biological fluids, relying on solvent extraction and gas chromatography. After oral administration, 69.4% of the sparteine was absorbed and peak plasma levels were reached after 46.5 min. After intravenous injection the plasma levels declined with a half life of 117 min. When sparteine is given intravenously, 34.2% of the dose administered is excreted in the urine in the next 24 h as unchanged sparteine. Two metabolites were found in the urine but have not yet been identified. They contribute only a few percent to the total urinary excretion of sparteine. Approximately 50% of sparteine is bound to plasma proteins. — The pharmacokinetics of sparteine after intravenous administration can be described in terms of a one-compartment model. —The tissue distribution of sparteine was studied in preliminary experiments in rats. The drug was accumulated in several tissues, with the greatest concentration in the lungs. The hypothesis is advanced that drugs, which are organic bases with high pKa-values and high lipid solubility, are concentrated mainly in the lungs, followed by the adrenals, spleen, and the heart.