Pharmacokinetics of ticlopidine during chronic oral administration to healthy volunteers and its effects on antipyrine pharmacokinetics

1. The pharmacokinetics of ticlopidine, a novel antithrombotic agent, have been investigated in 10 healthy volunteers dosed orally with the drug (250 mg 12 hourly for 21 days), to determine the basic pharmacokinetic parameters in humans, to investigate its accumulation during repeated administration, and to assess its effects on hepatic drug-metabolizing enzymes. 2. After the first dose, peak plasma concentrations (median 0.31, range 0.08-0.80 mg/l) were generally found at 2 h. The levels decreased rapidly to a median concentration of 0.087 mg/l by 4 h then declined to 0.022 (range