Comparison of gastrointestinal adverse effects of ketoprofen between adult and young cats.

This study elucidated differences in predisposition to the gastrointestinal adverse effects of ketoprofen between young and adult cats. Ketoprofen was administered subcutaneously (2.0 mg/kg, s.c.) once a day for 3 days. The animals were sacrificed 24 hr after final injection to allow examination of gastrointestinal mucosal lesions. Ketoprofen caused gastric lesions in adult cats (>6 months) but not in young cats (<3 months). Ketoprofen caused more severe small intestinal lesions in adult cats than in young cats. In the study of prevention of lipopolysaccharide (LPS)-induced hyperthermia using ketoprofen, young and adult cats of both sexes were administered LPS (0.3 μg/kg, intravenously), and body temperature was measured 24 hr later. Ketoprofen was administered subcutaneously 30 min before LPS injection. LPS-induced hyperthermia was almost completely inhibited by pretreatment with ketoprofen in both adult and young cats. In the pharmacokinetics of ketoprofen, plasma concentrations were analyzed by high-performance liquid chromatography. No significant differences were observed in plasma concentrations of two mirror-image R(-) and S(+) ketoprofen between young and adult cats from 0.5-4 hr after injection. As observed in a previous study using flunixin, the degree of gastrointestinal damage was unrelated to plasma concentrations of ketoprofen. The results of this study demonstrated that ketoprofen is safer for use in young cats than in adult cats from the viewpoint of gastrointestinal adverse effects.