2017 ACVIM Forum Research Abstract Program

This study was a masked, randomized, three-arm parallel study to determine the plasma PK of two dosages (0.5 and 2.0 mg/kg) of 2% MZP applied topically once daily for 14 days to healthy adult cats (6-13 years old) as determined by CBC/serum chemistry and physical exam. Twenty cats were randomized: eight to 0.5 mg/ kg, eight to 2.0 mg/kg, and four cats to no treatment. Cats underwent acclimation for 7 days, a dosing phase of 14 days, and a post-dosing phase of 3 days for PK sampling. Cats wore Elizabethan collars for the duration of the study. Cats were assessed daily for general health and application site abnormalities. Physical examinations and body weights were recorded at the beginning and end of the study. Plasma samples for mirtazapine concentrations were collected within one hour prior to treatment on the last dosing day, and at 1, 2, 4, 6, 8, 12, 24, 48, 72 and 96 h post final dosing and analyzed using a validated LC-MS/MS method. Noncompartmental pharmacokinetic analysis was performed with WinNonlin Professional ver 5.3.