Monocytosis after Methylprednisolone in cats

The FDA has received 23 reports of monocytosis in cats after Methylprednisolone. That is 1.4% of all reports for this medicine, compared with 0.3% across reports for all cat medicines, so it is reported unusually often with this medicine.

23Reports

83%Marked serious

0.0%Recovered

43%Died or euthanised

9 daysTypical onset

How soon it started

Same day

5 24%

1–2 days

5 24%

3–7 days

0 0.0%

1–4 weeks

8 38%

Over a month

3 14%

How the animals did

Still unwell when reported

11 48%

Died

1 4.3%

Euthanised

9 39%

Not known

2 8.7%

Problems reported at the same time

10 43%

10 43%

9 39%

9 39%

8 35%

7 30%

7 30%

7 30%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Type: medicine.

Questions owners ask

Can Methylprednisolone cause monocytosis in cats?: 23 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 9 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).

All reported side effects of Methylprednisolone in cats · Medicines most reported with monocytosis