The Plasma Level and Urinary Excretion of Pirenzepine Dihydrochloride (LS 519) in Man

Abstract

The plasmal level and urinary excretion of pirenzepine were investigated in man by radioimmunoassay after a single or multiple oral administration of pirenzepine tablets to healthy male volunteers. In a single administration (dose: 12.5, 25, 50 or 150 mg), the maximum plasma level appeared 2 hours after administration on average, the elimination half-life was about 13 hours on average, and urinary excretion rate within 96 hours was 7-12%. In multiple administration, three times a day (25 mg or 50 mg/time) for 4 days, the plasma level was observed to increase for the first 3 days of administration and to keep plateau thereafter. Also, the experimental values were in accordance with the simulation curve. These results suggested that the pharmacokinetic property of pirenzepine was not changed in different doses nor in multiple administration.