Influence of Thyroid Status on Plasma Half-Life of Antipyrine in Man

Abstract
The half-life of antipyrine in plasma was studied In four hyperthyroid and four hypothyroid patients before and after thyroid status returned to normal. The half-life (± S.E.M.) was 7.9 ± 1.0 hours In hyperthyroid and 17.3 ± 1.1 hours in hypothyroid patients. After correction of the abnormal thyroid state the half-life values of both groups (12.3 ± 0.7 and 12.0 ± 0.5 hours) were within the normal range. These results suggest that abnormalities of thyroid function can markedly influence human metabolism of some drugs. (N Engl J Med 290:1040–1042, 1974)