Lethargy after Cefazolin in cats

The FDA has received 29 reports of lethargy in cats after Cefazolin. That is 26% of all reports for this medicine, compared with 14% across reports for all cat medicines, so it is reported unusually often with this medicine.

29Reports
83%Marked serious
14%Recovered
45%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
12 44%
1–2 days
9 33%
3–7 days
3 11%
1–4 weeks
2 7.4%
Over a month
1 3.7%

How the animals did

Recovered
4 14%
Still unwell when reported
9 31%
Died
5 17%
Euthanised
8 28%
Not known
3 10%

Problems reported at the same time

13 45%
Liver problems
9 31%
Breathing problems
9 31%
7 24%
Kidney problems
7 24%
Blood problems
6 21%

Age of the animals

Under 1 year
4
1–3 years
7
4–7 years
7
8–11 years
5
12+ years
5

About this medicine

Type: medicine.

Questions owners ask

Can Cefazolin cause lethargy in cats?
29 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).

Lethargy with similar medicines

All reported side effects of Cefazolin in cats · Medicines most reported with lethargy