Vomiting after Imidacloprid + Moxidectin (Advantage Multi) in cats

The FDA has received 861 reports of vomiting in cats after Imidacloprid + Moxidectin. That is 11% of all reports for this medicine, compared with 18% across reports for all cat medicines, so it is reported less often than average with this medicine.

861Reports

58%Marked serious

37%Recovered

6.3%Died or euthanised

Same dayTypical onset

How soon it started

Same day

317 55%

1–2 days

166 29%

3–7 days

32 5.5%

1–4 weeks

34 5.9%

Over a month

31 5.3%

How the animals did

Recovered

321 37%

Recovered with lasting effects

1 0.1%

Still unwell when reported

28 3.3%

Died

35 4.1%

Euthanised

19 2.2%

Not known

457 53%

Problems reported at the same time

294 34%

245 28%

170 20%

103 12%

91 11%

59 6.9%

53 6.2%

Restlessness or agitation

51 5.9%

Age of the animals

Under 1 year

159

1–3 years

238

4–7 years

184

8–11 years

132

12+ years

112

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 vomiting in cats?: 861 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).

Vomiting with similar medicines

Vomiting after Spinosad (Comfortis) 8,410 reports · 73% of its reports
Vomiting after Nitenpyram (Capstar) 630 reports · 7.2% of its reports
Vomiting after Lufenuron 222 reports · 20% of its reports
Vomiting after Flumethrin + Imidacloprid (Seresto) 59 reports · 8.8% of its reports
Vomiting after Imidacloprid + Pyriproxyfen 68 reports · 10% of its reports
Vomiting after Fipronil 82 reports · 16% of its reports
Vomiting after Fipronil + S-methoprene (Frontline Plus) 54 reports · 15% of its reports
Vomiting after Imidacloprid 37 reports · 15% of its reports

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