Acute and chronic effects of tepoxalin on kidney function in dogs with chronic kidney disease and osteoarthritis

To determine whether tepoxalin alters kidney function in dogs with chronic kidney disease (CKD).

16 dogs with CKD (International Renal Interest Society stage 2 or 3) and osteoarthritis.

Kidney function was assessed via serum biochemical analysis, urinalysis, urine protein-to-creatinine concentration ratio, urine γ-glutamyl transpeptidase-to-creatinine concentration ratio, iohexol plasma clearance, and indirect blood pressure measurement twice before treatment. Dogs received tepoxalin (10 mg/kg, PO, q 24 h) for 28 days (acute phase; n = 16) and an additional 6 months (chronic phase; 10). Recheck examinations were performed weekly (acute phase) and at 1, 3, and 6 months (chronic phase). Kidney function variables were analyzed via repeated-measures ANOVA.

There was no difference over time for any variables in dogs completing both phases of the study. Adverse drug events (ADEs) resulting in discontinuation of tepoxalin administration included increased serum creatinine concentration (1 dog; week 1), collapse (1 dog; week 1), increased liver enzyme activities (1 dog; week 4), vomiting and diarrhea (1 dog; week 8), hematochezia (1 dog; week 24), and gastrointestinal ulceration or perforation (1 dog; week 26). Preexisting medical conditions and concomitant drug use may have contributed to ADEs. Kidney function was not affected in the latter 5 dogs. Discontinuation of tepoxalin administration stabilized kidney function in the former dog and resolved the ADEs in 4 of the 5 latter dogs.

Tepoxalin may be used, with appropriate monitoring, in dogs with International Renal Interest Society stage 2 or 3 CKD and osteoarthritis.