Behaviour change after Imidacloprid + Moxidectin (Advantage Multi) in cats

1,057 reports to the FDA describe behaviour change in cats given Imidacloprid + Moxidectin. That is 13% of all reports for this medicine, compared with 5.4% across reports for all cat medicines, so it is reported unusually often with this medicine.

1,057Reports

61%Marked serious

49%Recovered

3.2%Died or euthanised

Same dayTypical onset

How soon it started

Same day

560 69%

1–2 days

110 14%

3–7 days

30 3.7%

1–4 weeks

70 8.6%

Over a month

43 5.3%

How the animals did

Recovered

520 49%

Recovered with lasting effects

3 0.3%

Still unwell when reported

35 3.3%

Died

19 1.8%

Euthanised

15 1.4%

Not known

465 44%

Problems reported at the same time

Lethargy

209 20%

Restlessness or agitation

182 17%

Itching

180 17%

Drooling

164 16%

Loss of appetite

157 15%

Application site reaction

121 11%

Hiding

112 11%

Vomiting

91 8.6%

Age of the animals

Under 1 year

143

1–3 years

310

4–7 years

243

8–11 years

140

12+ years

111

About this medicine

Imidacloprid kills fleas (spot-on or collar). Moxidectin prevents heartworm disease (monthly topical, or a 6- or 12-month injection for dogs).

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

Questions owners ask

Can Imidacloprid + Moxidectin cause behaviour change in cats?: 1,057 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).

Behaviour change with similar medicines

Behaviour change after Spinosad (Comfortis) 359 reports · 3.1% of its reports
Behaviour change after Nitenpyram (Capstar) 564 reports · 6.5% of its reports
Behaviour change after Lufenuron 24 reports · 2.2% of its reports
Behaviour change after Flumethrin + Imidacloprid (Seresto) 68 reports · 10% of its reports
Behaviour change after Imidacloprid + Pyriproxyfen 80 reports · 12% of its reports
Behaviour change after Fipronil + S-methoprene (Frontline Plus) 23 reports · 6.3% of its reports
Behaviour change after Imidacloprid 26 reports · 10% of its reports

All reported side effects of Imidacloprid + Moxidectin in cats · Medicines most reported with behaviour change