[The pharmacokinetics of 14C-zolimidine in rats].

The blood levels and urinary and fecal excretion of 14C-zolimidine [2-(p-methylsulfonyl)-imidazo(1,2-a)pyridine-2-14Ci1 were studied following oral and intravenous application. The elimination from the blood after i.v. administration can be described by a 3-compartment model. Male rats eliminate the radioactivity more rapidly than do females. Although radioactivity is detectable for several days in the blood an accumulation of the drug or its metabolites can be excluded on the basis of the calculated values. 14C-Zolimidine is rapidly absorbed in rats after oral administration of 10 mg/kg and reaches peak blood levels within 45 to 60 min. In the first phase the elimination is rapid but trace activity can be measured for several days. Based on the amount of urinary excretion the rate of absorption is estimated to between 80 and 90%. Biliary excretion amounted to about 15% of the i.v. administered dose. It is assumed that the difference of 25% between fecal and biliary excretion is sequestered through the gastrointestinal mucosa.