Pharmacokinetic parameters of thiamazole in hyperthyroid patients responding rapidly and slowly to the treatment

Pharmacokinetic parameters of thiamazole were compared in two groups of patients with hyperthyroidism due to Graves-Basedow disease, differing in the period required to achieve clinical euthyrosis (less than 28 days, group R, n = 23, and not less than 35 days, group D, n = 18) after treatment with the "full" dose of the drug. The drug absorption from the GI tract in both groups was similar, but the serum concentrations of the drug (Cmax and AUC) were higher, and distribution volume and total clearance lower in the R than in D group. No evidence was found for the importance of initial plasma levels of thyroxine or triiodothyronine on pharmacokinetic parameters of thiamazole.