Increased heart rate after Nitenpyram (Capstar) in cats

136 reports to the FDA describe increased heart rate in cats given Nitenpyram. That is 1.6% of all reports for this medicine, compared with 0.3% across reports for all cat medicines, so it is reported unusually often with this medicine.

136Reports

18%Marked serious

46%Recovered

3.7%Died or euthanised

Same dayTypical onset

How soon it started

Same day

108 86%

1–2 days

4 3.2%

3–7 days

3 2.4%

1–4 weeks

2 1.6%

Over a month

8 6.4%

How the animals did

Recovered

63 46%

Still unwell when reported

23 17%

Died

4 2.9%

Euthanised

1 0.7%

Not known

45 33%

Problems reported at the same time

Breathing problems

104 76%

Restlessness or agitation

93 68%

41 30%

38 28%

22 16%

16 12%

15 11%

13 9.6%

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 increased heart rate in cats?: 136 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 the same 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).

Increased heart rate with similar medicines

Increased heart rate after Spinosad (Comfortis) 23 reports · 0.2% of its reports

All reported side effects of Nitenpyram in cats · Medicines most reported with increased heart rate