Abstract

To investigate the effects of nonsteroidal antiinflammatory drugs (NSAIDs) on thyroid tests, 25 healthy subjects underwent a single-dose study and/or a 1-wk study. In the single-dose study, subjects received a single dose of one of six NSAIDs (aspirin, salsalate, meclofenamate, ibuprofen, naproxen, or indomethacin) at 0800 h. Total and free thyroid hormones and TSH were analyzed 0, 1, 2, 3, 4, and 8 h later. In the 1-wk study, subjects received one of six NSAIDs for 7 d. Thyroid hormones and TSH were analyzed at 0800 h each day. Total T4 and total T3 were measured by RIA, free T4 and free T3 were measured by equilibrium dialysis, and TSH was measured by immunometric assay. There were no changes in any hormones after a single dose or 1 wk of ibuprofen, naproxen, or indomethacin. Single-dose aspirin or salsalate decreased, whereas meclofenamate increased, various total and free thyroid hormone measurements. One week of aspirin or salsalate decreased total T4, free T4 (salsalate only), total T3, free T3, and TSH. These data confirm that aspirin, salsalate, and meclofenamate affect total and free thyroid hormone measurements and identify three NSAIDs that did not change thyroid tests. TSH remained within the normal range during acute or 1-wk administration of all of the NSAIDs.

You do not currently have access to this article.