The pharmacokinetics of exaprolol and propranolol in rats with interrupted enterohepatic circulation

The pharmacokinetics of two beta adrenoceptor blocking drugs, exaprolol and propranolol, in rats with interrupted enterohepatic circulation was studied. The tritium-labelled drugs were given intravenously to four groups of rats: control, bile-duct cannulated, bile-duct ligated, and pretreated with neomycin. Plasma levels and excretion were observed up to 96 h after administration. The pharmacokinetic parameters show an enhanced plasma elimination of both drugs at interrupted enterohepatic circulation compared to the control group. Significant changes were observed in the excretion pattern with bile-duct cannulated and bile-duct ligated rats, while the total radioactivity excreted in urine and faeces does not differ between control and neomycin pretreated rats.