Didn't stop fleas after Nitenpyram (Capstar) in cats

2,325 reports to the FDA describe didn't stop fleas in cats given Nitenpyram. That is 27% of all reports for this medicine, compared with 8.4% across reports for all cat medicines, so it is reported unusually often with this medicine.

2,325Reports

3.5%Marked serious

2.1%Recovered

0.8%Died or euthanised

6 daysTypical onset

How soon it started

Same day

286 19%

1–2 days

354 23%

3–7 days

228 15%

1–4 weeks

398 26%

Over a month

277 18%

How the animals did

Recovered

49 2.1%

Still unwell when reported

244 10%

Died

13 0.6%

Euthanised

5 0.2%

Not known

2,014 87%

Problems reported at the same time

Itching

187 8.0%

Didn't work as expected

169 7.3%

Restlessness or agitation

82 3.5%

64 2.8%

59 2.5%

58 2.5%

43 1.8%

37 1.6%

Age of the animals

Under 1 year

282

1–3 years

560

4–7 years

397

8–11 years

271

12+ years

208

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 didn't stop fleas in cats?: 2,325 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 6 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).

Didn't stop fleas with similar medicines

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Didn't stop fleas after Imidacloprid + Moxidectin (Advantage Multi) 1,073 reports · 13% of its reports
Didn't stop fleas after Lufenuron 89 reports · 8.0% of its reports
Didn't stop fleas after Flumethrin + Imidacloprid (Seresto) 255 reports · 38% of its reports
Didn't stop fleas after Imidacloprid + Pyriproxyfen 282 reports · 43% of its reports
Didn't stop fleas after Fipronil 190 reports · 38% of its reports
Didn't stop fleas after Fipronil + S-methoprene (Frontline Plus) 134 reports · 37% of its reports
Didn't stop fleas after Imidacloprid 104 reports · 41% of its reports

All reported side effects of Nitenpyram in cats · Medicines most reported with didn't stop fleas