3H-Cymarol in man. Excretion pathways and serum protein binding

In 10 patients, 5 having received 3H-cymarol i.v., 5 orally, the radioactivity in plasma, urine and in the feces of some patients also was determined. After oral administration the plasma levels rose rapidly reaching maximum levels 1--2 h after administration. After i.v. injection about 30% of the given radioactivity were excreted in the urine. The remaining radioactivity was found in the feces suggesting a high biliary excretion. Only 10% of the radioactivity excreted in the first 24 h were chloroform-extractable. The radioactivity found in the urine after oral administration of the drug amounted to 17.6%. Between 51.1 and 58.5% of the drug were bound to serum proteins.