OBJECTIVE: To evaluate the effects of firocoxib, meloxicam, and tepoxalin administration in healthy cats by measuring the ability of stimulated tissues to synthesize eicosanoids ex vivo. ANIMALS: 8 healthy adult male cats. PROCEDURES: In a blinded, randomized, crossover study design, cats were treated with firocoxib (1 mg/kg, PO, q 24 h), meloxicam (0.05 mg/kg, PO, q 24 h), tepoxalin (5.0 mg/kg, PO, q 12 h), or a placebo for 8 days. Blood samples and gastric and duodenal mucosal biopsy specimens were collected on days 0 (baseline; immediately before treatment), 3, and 8 of each treatment period. Thromboxane B2 (TXB2) concentrations were measured in serum, and prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) concentrations were measured in plasma. Prostaglandin E1 (PGE1) synthesis, PGE2 synthesis, and LTB4 concentrations were measured in mucosal biopsy specimens. A 21-day minimum washout period was observed between treatments. Repeated-measures analyses were performed. RESULTS: Firocoxib and meloxicam administration resulted in a lower plasma PGE2 concentration than at baseline on days 3 and 8 of administration, whereas tepoxalin administration did not. Tepoxalin administration resulted in a lower serum TXB2 concentration and pyloric and duodenal PGE1 synthesis on both days, compared with baseline and placebo administration. Neither firocoxib nor meloxicam administration altered pyloric or duodenal PGE1 synthesis on either day, compared with placebo administration. Tepoxalin administration also resulted in lower pyloric mucosal LTB4 concentrations on both days, compared with baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: Firocoxib and meloxicam administration had no effect on cyclooxygenase-1 activity, whereas tepoxalin administration resulted in inhibition of cyclooxygenase-1 and 5-lipoxygenase.
OBJECTIVE: To evaluate the effects of firocoxib, meloxicam, and tepoxalin administration in healthy cats by measuring the ability of stimulated tissues to synthesize eicosanoids ex vivo. ANIMALS: 8 healthy adult male cats. PROCEDURES: In a blinded, randomized, crossover study design, cats were treated with firocoxib (1 mg/kg, PO, q 24 h), meloxicam (0.05 mg/kg, PO, q 24 h), tepoxalin (5.0 mg/kg, PO, q 12 h), or a placebo for 8 days. Blood samples and gastric and duodenal mucosal biopsy specimens were collected on days 0 (baseline; immediately before treatment), 3, and 8 of each treatment period. Thromboxane B2 (TXB2) concentrations were measured in serum, and prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) concentrations were measured in plasma. Prostaglandin E1 (PGE1) synthesis, PGE2 synthesis, and LTB4 concentrations were measured in mucosal biopsy specimens. A 21-day minimum washout period was observed between treatments. Repeated-measures analyses were performed. RESULTS:Firocoxib and meloxicam administration resulted in a lower plasma PGE2 concentration than at baseline on days 3 and 8 of administration, whereas tepoxalin administration did not. Tepoxalin administration resulted in a lower serum TXB2 concentration and pyloric and duodenal PGE1 synthesis on both days, compared with baseline and placebo administration. Neither firocoxib nor meloxicam administration altered pyloric or duodenal PGE1 synthesis on either day, compared with placebo administration. Tepoxalin administration also resulted in lower pyloric mucosal LTB4 concentrations on both days, compared with baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: Firocoxib and meloxicam administration had no effect on cyclooxygenase-1 activity, whereas tepoxalin administration resulted in inhibition of cyclooxygenase-1 and 5-lipoxygenase.