Restlessness or agitation after Flumethrin + Imidacloprid (Seresto) in cats

The FDA has received 27 reports of restlessness or agitation in cats after Flumethrin + Imidacloprid. That is 4.0% of all reports for this medicine, compared with 4.9% across reports for all cat medicines.

27Reports

48%Marked serious

48%Recovered

0.0%Died or euthanised

44 daysTypical onset

How soon it started

Same day

3 14%

1–2 days

0 0.0%

3–7 days

3 14%

1–4 weeks

4 19%

Over a month

11 52%

How the animals did

Recovered

13 48%

Not known

14 52%

Problems reported at the same time

12 44%

8 30%

7 26%

7 26%

Dilated pupils

5 19%

Hair loss

4 15%

Application site reaction

4 15%

Didn't stop fleas

4 15%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Imidacloprid kills fleas (spot-on or collar).

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

Questions owners ask

Can Flumethrin + Imidacloprid cause restlessness or agitation in cats?: 27 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 44 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).

Restlessness or agitation with similar medicines

Restlessness or agitation after Spinosad (Comfortis) 229 reports · 2.0% of its reports
Restlessness or agitation after Nitenpyram (Capstar) 2,987 reports · 34% of its reports
Restlessness or agitation after Imidacloprid + Moxidectin (Advantage Multi) 682 reports · 8.4% of its reports
Restlessness or agitation after Lufenuron 20 reports · 1.8% of its reports
Restlessness or agitation after Imidacloprid + Pyriproxyfen 46 reports · 7.0% of its reports
Restlessness or agitation after Fipronil 59 reports · 12% of its reports
Restlessness or agitation after Fipronil + S-methoprene (Frontline Plus) 33 reports · 9.0% of its reports
Restlessness or agitation after Imidacloprid 28 reports · 11% of its reports

All reported side effects of Flumethrin + Imidacloprid in cats · Medicines most reported with restlessness or agitation