Neutrophilia after Nitenpyram (Capstar) in cats

The FDA has received 21 reports of neutrophilia in cats after Nitenpyram. That is 0.2% of all reports for this medicine, compared with 0.7% across reports for all cat medicines, so it is reported less often than average with this medicine.

21Reports

57%Marked serious

24%Recovered

29%Died or euthanised

2 daysTypical onset

How soon it started

Same day

1 8.3%

1–2 days

7 58%

3–7 days

1 8.3%

1–4 weeks

0 0.0%

Over a month

3 25%

How the animals did

Recovered

3 14%

Recovered with lasting effects

2 9.5%

Died

4 19%

Euthanised

2 9.5%

Not known

10 48%

Problems reported at the same time

11 52%

10 48%

10 48%

8 38%

7 33%

6 29%

6 29%

6 29%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

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 neutrophilia in cats?: 21 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 2 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).

Neutrophilia with similar medicines

Neutrophilia after Spinosad (Comfortis) 37 reports · 0.3% of its reports

All reported side effects of Nitenpyram in cats · Medicines most reported with neutrophilia