Urinary tract infection after Methimazole in cats

28 reports to the FDA describe urinary tract infection in cats given Methimazole. That is 1.6% of all reports for this medicine, compared with 0.5% across reports for all cat medicines, so it is reported unusually often with this medicine.

28Reports

86%Marked serious

18%Recovered

11%Died or euthanised

58 daysTypical onset

How soon it started

Same day

2 11%

1–2 days

0 0.0%

3–7 days

1 5.3%

1–4 weeks

2 11%

Over a month

14 74%

How the animals did

Recovered

5 18%

Still unwell when reported

12 43%

Died

3 11%

Not known

8 29%

Problems reported at the same time

8 29%

8 29%

7 25%

6 21%

6 21%

6 21%

Decreased haematocrit

6 21%

Vomiting

5 18%

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 urinary tract infection in cats?: 28 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 58 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).

Urinary tract infection with similar medicines

Urinary tract infection after Velagliflozin (Senvelgo) 171 reports · 3.6% of its reports
Urinary tract infection after Bexagliflozin (Bexacat) 125 reports · 3.1% of its reports
Urinary tract infection after Insulin 63 reports · 1.7% of its reports

All reported side effects of Methimazole in cats · Medicines most reported with urinary tract infection