Tremors after Methimazole in cats

32 reports to the FDA describe tremors in cats given Methimazole. That is 1.8% of all reports for this medicine, compared with 2.6% across reports for all cat medicines.

32Reports

63%Marked serious

25%Recovered

9.4%Died or euthanised

7 daysTypical onset

How soon it started

Same day

9 38%

1–2 days

2 8.3%

3–7 days

2 8.3%

1–4 weeks

4 17%

Over a month

7 29%

How the animals did

Recovered

6 19%

Recovered with lasting effects

2 6.3%

Still unwell when reported

12 38%

Died

2 6.3%

Euthanised

1 3.1%

Not known

9 28%

Problems reported at the same time

12 38%

8 25%

8 25%

7 22%

6 19%

5 16%

5 16%

4 13%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Methimazole treats an overactive thyroid in cats.

Questions owners ask

Can Methimazole cause tremors in cats?: 32 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 7 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).

Tremors with similar medicines

Tremors after Insulin 41 reports · 1.1% of its reports

All reported side effects of Methimazole in cats · Medicines most reported with tremors