Wobbliness (ataxia) after Nitenpyram (Capstar) in cats

The FDA has received 171 reports of wobbliness (ataxia) in cats after Nitenpyram. That is 2.0% of all reports for this medicine, compared with 4.7% across reports for all cat medicines, so it is reported less often than average with this medicine.

171Reports
40%Marked serious
13%Recovered
23%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
42 45%
1–2 days
27 29%
3–7 days
4 4.3%
1–4 weeks
10 11%
Over a month
11 12%

How the animals did

Recovered
22 13%
Still unwell when reported
32 19%
Died
21 12%
Euthanised
18 11%
Not known
78 46%

Problems reported at the same time

Age of the animals

Under 1 year
50
1–3 years
24
4–7 years
25
8–11 years
28
12+ years
41

About this medicine

Nitenpyram kills adult fleas quickly; a single-dose tablet.

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

Questions owners ask

Can Nitenpyram cause wobbliness (ataxia) in cats?
171 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).

Wobbliness (ataxia) with similar medicines

All reported side effects of Nitenpyram in cats · Medicines most reported with wobbliness (ataxia)