Weight loss after Mirtazapine (Mirataz) in cats

The FDA has received 184 reports of weight loss in cats after Mirtazapine. That is 9.8% of all reports for this medicine, compared with 4.6% across reports for all cat medicines, so it is reported unusually often with this medicine.

184Reports

73%Marked serious

9.8%Recovered

32%Died or euthanised

10 daysTypical onset

How soon it started

Same day

27 17%

1–2 days

29 18%

3–7 days

19 12%

1–4 weeks

36 23%

Over a month

48 30%

How the animals did

Recovered

18 9.8%

Still unwell when reported

58 32%

Died

17 9.2%

Euthanised

42 23%

Not known

49 27%

Problems reported at the same time

130 71%

69 38%

59 32%

54 29%

48 26%

Didn't work as expected

47 26%

Liver problems

40 22%

Dehydration

33 18%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Mirtazapine stimulates appetite (cats: ointment applied to the ear).

Products with this ingredient include Mirataz. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Questions owners ask

Can Mirtazapine cause weight loss in cats?: 184 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
How soon after a dose was it reported?: In half of the reports with dates, it started within 10 days of the first dose.
What should I do?: Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).

Weight loss with similar medicines

Weight loss after Maropitant (Cerenia) 370 reports · 9.6% of its reports
Weight loss after Capromorelin (Entyce) 54 reports · 6.6% of its reports

All reported side effects of Mirtazapine in cats · Medicines most reported with weight loss