Cats with
chronic kidney disease (CKD) often experience inappetence and
vomiting and might benefit from the administration of
mirtazapine, a medication with appetite stimulant and anti-
nausea properties. The aim of this placebo-controlled, double-masked crossover clinical trial was to evaluate the effects of
mirtazapine on bodyweight, appetite and
vomiting in cats with CKD. Eleven cats with stable CKD were randomized to receive 1.88 mg
mirtazapine or placebo orally every other day for 3 weeks. After a 4 day washout period, each cat crossed over to the alternate treatment for 3 weeks. Physical examinations and serum biochemistry profiles were performed before and after each treatment period and owners kept daily logs of appetite, activity, behavior, and
vomiting episodes. Compared to placebo,
mirtazapine administration resulted in a statistically significant increase in appetite (P=0.02) and activity (P=0.02) and a statistically significant decrease in
vomiting (P=0.047), as determined by Wilcoxon matched pairs analysis. Cats treated with
mirtazapine also gained significant bodyweight compared with placebo-treated cats (P=0.002) as determined by linear mixed model analysis. Median
weight gain during
mirtazapine administration was 0.18 kg (range 0-0.45 kg). Median
weight loss during placebo administration was 0.07 kg (range 0-0.34 kg).
Mirtazapine is an effective appetite stimulant and
anti-emetic for cats with CKD and could be a useful adjunct to the nutritional management of these cases.