Plasma turnover and excretion of K-strophanthoside-³H in human volunteers after parenteral administration

Summary

Pharmacokinetic parameters of K-strophanthoside-³H, a short-acting cardiac glycoside, were investigated in healthy subjects, patients suffering from heart disease, renal failure and in cholecystec-tomized patients with a biliary T-tube inserted surgically, after parenteral administration of 250 μg of the glycoside. The healthy subjects, patients suffering from heart disease and those with the biliary T-tube showed a dominant half-time for plasma turnover of the glycoside of 15–16 h after the i.v. route and 18–22 h after the i.m. route and cumulative urinary excretion of the drug over a 24 h period of 37–42% (i.v. route) and 32–33% (i.m. route). The volumes of distribution were lower in patients with heart disease and patients with biliary fistula than in the healthy subjects. In patients suffering from renal failure the dominant half-time of plasma turnover was higher (33 h), while cumulative urinary excretion of the glycoside (12%) and the volumes of distribution were lower than in the healthy subjects. A peak of plasma levels 30 min after i.m. administration of K-strophanthoside-³H leads to the conclusion that this glycoside is rapidly absorbed when injected intramuscularly.