Pharmacokinetic investigations with 3H-penta-acetyl-gitoxin in volunteers and patients with respect to the occurrence of drug latentiation.

After oral administration of 3H-penta-acetyl-gitoxin (Pengitoxin W.H.O., Pentagit) 1.5 mg to four volunteers, serum radioactivity diclines with a half-life of 62 +/- 10 hours. After an oral maintenance dose of 0.4 mg pengitoxin in five digitalized patients, four of them with a cannulated bile duct, serum radioactivity declines with half-life of 56 +/- 8 hours. In volunteers within 4 days 50.7% of the administered radioactivity is excreted in urine; in the patients 52.3% in urine and 28.0% in bile. By thin-layer chromatographic studies, 16-acetyl-gitoxin was charactrized as the main metabolite in serum, bile and urine. Furthermore, in the first 8 hours after administration, two additional metabolites occur in urine.