Effects of commonly prescribed nonsteroidal anti-inflammatory drugs on thyroid hormone measurements.
OBJECTIVE
To assess the effects of nonsteroidal anti-inflammatory drugs (NSAIDs) on thyroid function tests.


METHODS
Eighty-nine patients receiving NSAIDs and 22 control subjects not taking NSAIDs were studied in a cross-sectional survey at Veterans Affairs and University hospitals. Measurements of serum thyroxine (T4), free T4 index, triiodothyronine (T3), and thyrotropin (thyroid-stimulating hormone [TSH]) were obtained for all subjects.


RESULTS
Serum T4 measurements were lowered only in salsalate-treated patients, while serum T3 was depressed in patients receiving salsalate, diclofenac sodium, and naproxen. Serum T4 and T3 were unchanged in patients treated with diflunisal, ibuprofen, indomethacin, piroxicam, or sulindac. Serum TSH was normal in all subjects.


CONCLUSIONS
Several NSAIDs can lower serum thyroid hormone concentrations, principally by interfering with the binding of T4 and T3 to serum carrier proteins; patients taking these drugs remain euthyroid. Awareness of these interactions may prevent unnecessary diagnostic or therapeutic interventions.
Bishnoi
A
A
Medical Service, Northport Veterans Affairs Medical Center, New York 11768.
Carlson
H E
HE
Gruber
B L
BL
Kaufman
L D
LD
Bock
J L
JL
Lidonnici
K
K
D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013960:Thyroid Function Tests; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D000894:Anti-Inflammatory Agents, Non-Steroidal; D013963:Thyroid Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine