Effects of oral trazodone on echocardiographic and hemodynamic variables in healthy cats

Objectives: The purpose of this study was to evaluate the effects of oral trazodone on echocardiographic variables, heart rate (HR) and blood pressure (BP) in healthy cats. Methods: Client-owned domestic cats between 2 and 8 years of age were recruited. Cats were considered healthy based on physical examination, complete blood count, blood chemistry profile, urinalysis, total thyroxine concentration, non-invasive BP measurement by Doppler method and a screening transthoracic echocardiogram with simultaneous electrocardiogram. Echocardiographic variables assessed pre-trazodone and 90–120 mins post-trazodone (50 mg PO) included left ventricular internal diameter in systole and diastole, interventricular septal and left ventricular free-wall thickness in systole and diastole, left atrial size, left auricular function and left ventricular diastolic function assessed by spectral Doppler transmitral and pulmonary venous flow velocities, and tissue Doppler profiles. Mean echocardiographic and hemodynamic variables were calculated for pre- and post-trazodone examinations for each cat. Pre- and post-trazodone variables were analyzed with a paired t-test with significance set at P <0.05. Results: Twelve healthy cats were evaluated. Trazodone was administered to all cats and a sedative effect was observed. There were no clinically significant differences in any echocardiographic variables post-trazodone administration. Systolic BP was significantly decreased after trazodone (P = 0.001) with no significant change in HR. Conclusions and relevance: Trazodone did not alter echocardiographic variables, in a clinically relevant manner, in this group of healthy cats. Trazodone may aid in obtaining transthoracic echocardiograms without affecting HR or echocardiographic variables but may significantly lower BP in healthy cats.