A pharmacokinetic study of oclacitinib maleate in six cats

Background Oclacitinib is a Janus kinase (JK)1 inhibitor that has been shown to be effective and safe for the treatment of allergic dermatitis in dogs. Its use in cats has been limited by the absence of pharmacokinetic data. Objective To determine the pharmacokinetic parameters of oclacitinib in cats after oral and intravenous administration. Animals Six adult domestic short hair cats. Methods and materials A two period, two treatment design was used in which cats received oclacitinib maleate i.v. and p.o., at a dose of 0.5 mg/kg and 1 mg/kg, respectively. There was a one‐week interval of washout between the two treatments. Cats received each treatment only once. The plasma concentration of oclacitinib was determined by high‐performance liquid chromatography at 0 min, 5 min, 15 min, 30 min, 1 h, 4 h, 6 h, 10 h and 24 h after intravenous.v administration, at 0 min, 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 10 h and 24 h after p.o. administration. Results After p.o. administration, oclacitinib was absorbed rapidly and almost completely, as shown by an absolute bioavailability of 87% and a T max of 35 min. The elimination of the drug also was very rapid as shown by a half‐life of 2.3 h and a clearance calculated as 4.45 mL/min/kg (after i.v. administration). Conclusions and clinical importance The pharmacokinetic parameters of oclacitinib in the cat are similar to those described for the dog, although absorption and elimination are somewhat faster and variability between individuals is somewhat greater. Larger doses and/or shorter dosing intervals would be recommended in cats to achieve similar blood concentrations to those in dogs.