Anisocoria after Maropitant (Cerenia) in cats

The FDA has received 51 reports of anisocoria in cats after Maropitant. That is 1.3% of all reports for this medicine, compared with 0.4% across reports for all cat medicines, so it is reported unusually often with this medicine.

51Reports

71%Marked serious

27%Recovered

14%Died or euthanised

1 daysTypical onset

How soon it started

Same day

15 34%

1–2 days

13 30%

3–7 days

7 16%

1–4 weeks

7 16%

Over a month

2 4.5%

How the animals did

Recovered

14 27%

Still unwell when reported

15 29%

Died

6 12%

Euthanised

1 2.0%

Not known

15 29%

Problems reported at the same time

30 59%

25 49%

15 29%

14 27%

11 22%

11 22%

10 20%

9 18%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Maropitant prevents vomiting and motion sickness.

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

Questions owners ask

Can Maropitant cause anisocoria in cats?: 51 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 1 day 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).

All reported side effects of Maropitant in cats · Medicines most reported with anisocoria