Didn't work as expected after Fipronil + Pyriproxyfen + S-methoprene in dogs

The FDA has received 59 reports of didn't work as expected in dogs after Fipronil + Pyriproxyfen + S-methoprene. That is 14% of all reports for this medicine, compared with 13% across reports for all dog medicines.

59Reports

6.8%Marked serious

12%Recovered

1.7%Died or euthanised

127 daysTypical onset

How soon it started

Same day

1 3.2%

1–2 days

1 3.2%

3–7 days

1 3.2%

1–4 weeks

6 19%

Over a month

22 71%

How the animals did

Recovered

7 12%

Still unwell when reported

9 15%

Euthanised

1 1.7%

Not known

42 71%

Problems reported at the same time

Didn't stop ticks

28 47%

Skin disorders

2 3.4%

Cough

2 3.4%

Itching

1 1.7%

Vomiting

1 1.7%

Skin rash or irritation

1 1.7%

Didn't stop fleas

1 1.7%

Drug dose administration interval too long

1 1.7%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Fipronil kills fleas and ticks (spot-on).

Questions owners ask

Can Fipronil + Pyriproxyfen + S-methoprene cause didn't work as expected in dogs?: 59 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 127 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).

Didn't work as expected with similar medicines

Didn't work as expected after Spinosad (Comfortis) 1,731 reports · 3.0% of its reports
Didn't work as expected after Lufenuron + Milbemycin Oxime (Sentinel) 4,480 reports · 17% of its reports
Didn't work as expected after Imidacloprid + Moxidectin (Advantage Multi) 631 reports · 4.8% of its reports
Didn't work as expected after Nitenpyram (Capstar) 803 reports · 7.4% of its reports
Didn't work as expected after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 1,429 reports · 14% of its reports
Didn't work as expected after Fipronil + S-methoprene (Frontline Plus) 243 reports · 8.2% of its reports
Didn't work as expected after Flumethrin + Imidacloprid (Seresto) 209 reports · 9.2% of its reports
Didn't work as expected after Imidacloprid 105 reports · 5.5% of its reports
Didn't work as expected after Fipronil 152 reports · 11% of its reports
Didn't work as expected after Imidacloprid + Permethrin + Pyriproxyfen 30 reports · 4.1% of its reports

All reported side effects of Fipronil + Pyriproxyfen + S-methoprene in dogs · Medicines most reported with didn't work as expected