ABSTRACT
Six healthy volunteers participated in a single-dose study of pharmacokinetics and metabolism of oral administration of [3H]-pipethiaden (1 mg). Plasma levels of total radioactivity, urinary excretion and metabolism were analyzed by liquid scintillation counting and radio-TLC. The mean peak plasma concentration of radioactive metabolites was 4.9 ng eq/ml, and the mean elimination half life was 11.5 h. 34% of radioactivity was recovered in 4 days in urine, with only 0.4% present as unchanged drug. Pipethiaden was extensively metabolized by S-oxidation, N-demethylation, and N-oxidation.
Subject(s)
Piperidines/pharmacokinetics , Adult , Humans , Male , Middle Aged , TritiumABSTRACT
The authors investigated the metipranolol plasma concentration in seven patients with renal failure after a single dose of 20 mg of the preparation (2 tablets of Trimepranol) by the oral route during haemodialysis and on days without dialysis, and evaluated also the effect of dialysis on selected pharmacokinetic constants. Although there was a great individual variability of plasma concentrations of metipranolol, these concentrations were at the end of dialysis lower than during the corresponding interval between dialyses. The mean values of the area beneath the concentration curve, the velocity elimination constants, the half-life of elimination and total clearance indicate a certain dialysability of metipranolol. During the practical application of these conclusions it is, however, important to consider the effect on blood pressure and cardiac rhythm resp. by changes of volume and the composition of the extracellular fluid caused by haemodialysis.
