[The influence of primidone on thyroid function (author's transl)].

The influence of primidone on thyroxine level, T3 index, FT4 index, triiodothyronine level, T3 (RIA)/T4 (RIA) quotient as well as on the TSH basal and stimulated values was investigated in 30 children on long-term treatment. The values obtained were compared statistically with those of a normal group. During primidone treatment a drop in T4 level and in FT4 index as well as an increase in T3 (RIA)/T4 (RIA) quotient was observed. On the other hand the triiodothyronine level and the T3 index were not influenced. The TSH basal and stimulated values were not statistically different from the control group. Thus the primidone-treated children are euthyroid according to the TRH test. Primidone probably stimulates hepatocellular thyroxine breakdown.