Lethargy after Nitenpyram (Capstar) in dogs

The FDA has received 1,204 reports of lethargy in dogs after Nitenpyram. That is 11% of all reports for this medicine, compared with 11% across reports for all dog medicines.

1,204Reports

21%Marked serious

22%Recovered

8.8%Died or euthanised

1 daysTypical onset

How soon it started

Same day

359 47%

1–2 days

251 33%

3–7 days

60 7.9%

1–4 weeks

39 5.1%

Over a month

52 6.8%

How the animals did

Recovered

259 22%

Recovered with lasting effects

6 0.5%

Still unwell when reported

240 20%

Died

83 6.9%

Euthanised

23 1.9%

Not known

593 49%

Problems reported at the same time

458 38%

387 32%

180 15%

141 12%

122 10%

110 9.1%

102 8.5%

97 8.1%

Age of the animals

Under 1 year

243

1–3 years

301

4–7 years

304

8–11 years

204

12+ years

114

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 lethargy in dogs?: 1,204 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

Lethargy after Spinosad (Comfortis) 7,303 reports · 13% of its reports
Lethargy after Lufenuron + Milbemycin Oxime (Sentinel) 2,341 reports · 9.0% of its reports
Lethargy after Imidacloprid + Moxidectin (Advantage Multi) 2,000 reports · 15% of its reports
Lethargy after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 666 reports · 6.7% of its reports
Lethargy after Fipronil + S-methoprene (Frontline Plus) 447 reports · 15% of its reports
Lethargy after Flumethrin + Imidacloprid (Seresto) 250 reports · 11% of its reports
Lethargy after Imidacloprid 196 reports · 10% of its reports
Lethargy after Fipronil 185 reports · 13% of its reports
Lethargy after Lufenuron 205 reports · 20% of its reports
Lethargy after Imidacloprid + Permethrin + Pyriproxyfen 106 reports · 14% of its reports

All reported side effects of Nitenpyram in dogs · Medicines most reported with lethargy