Abstract: Background - Time- and dose-dependent side effects of amiodarone have not been described in cats. Hypothesis/Objectives - Report laboratory findings, adverse events, and clinical outcome in cats receiving amiodarone therapy. Animals - Twenty-seven client-owned cats treated with amiodarone Methods - Medical records were reviewed for signalment, arrhythmia diagnosis, presence of structural heart disease and congestive heart failure at presentation, amiodarone dose, and adverse events. The median ALT, ALP, and T4 values were compared before and after short-term treatment (0-3 months) and long-term treatment (> 6 months). Results – Amiodarone was most commonly prescribed for ventricular arrhythmias with a median dose of 50 mg/cat/day (range 25-50 mg/cat/day). Most cats had cardiomyopathic disease (26/27; 96%) and many were in congestive heart failure (17/27; 63%) at presentation. Cats received amiodarone for a median of 141 days (range 3 - 1543 days). The ALT significantly decreased following short-term treatment (n = 19; P = 0.01), but there was no significant difference in ALP (n = 19; P = 0.94) and T4 (n = 4; P = 0.25). There was no significant difference in ALT (n = 9; P = 0.65) and ALP (n = 10; P = 0.87) in cats treated with amiodarone for more than 6 months. Ten cats (37%) had at least one episode of hyporexia or vomiting while receiving amiodarone. Conclusions and clinical importance - In cats, amiodarone was used primarily for ventricular arrhythmias and appeared to be generally well tolerated. Transient gastrointestinal signs were reported in cats receiving amiodarone.
.jpg "Graham C. Rossi, DVM (he/him/his) photo")
