Effect of Dosing and Sampling Time on Serum Thyroxine, Free Thyroxine, and Thyrotropin Concentrations in Dogs Following Multidose Etodolac Administration

摘要

Thirty-eight dogs with orthopedic disorders received etodolac, an NSAID, at 10.0 to 13.3 mg/kg PO once daily for 14 to 19 days. Mean total thyroxine (T_4), free thyroxine (fT_4), and canine thyrotropin (cTSH) values before and after etodolac administration were compared using paired t-tests. A significant (P < .05) decrease in T_4 values occurred after etodolac administration with 21% of these values falling below the reference range. A significant (P < .05) increase in cTSH following etodolac administration, but none of the values was above the reference range. No significant changes occurred in mean fT_4 values; however, 10% of the values fell below the reference range. In conclusion, T_4 and fT_4 test results should be interpreted with caution in dogs receiving etodolac.