Didn't prevent heartworm after Praziquantel + Pyrantel in dogs

The FDA has received 26 reports of didn't prevent heartworm in dogs after Praziquantel + Pyrantel. That is 0.7% of all reports for this medicine, compared with 13% across reports for all dog medicines, so it is reported less often than average with this medicine.

26Reports

19%Marked serious

3.8%Recovered

3.8%Died or euthanised

–Typical onset

How the animals did

Recovered

1 3.8%

Still unwell when reported

3 12%

Died

1 3.8%

Not known

21 81%

Problems reported at the same time

Didn't stop worms

3 12%

Didn't work as expected

2 7.7%

Behaviour change

2 7.7%

Vomiting

2 7.7%

Weight gain

2 7.7%

Drug administration error

2 7.7%

Seizures

1 3.8%

Neurological signs

1 3.8%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Praziquantel treats tapeworms. Pyrantel treats roundworms and hookworms.

Questions owners ask

Can Praziquantel + Pyrantel cause didn't prevent heartworm in dogs?: 26 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.
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 prevent heartworm with similar medicines

Didn't prevent heartworm after Pyrantel + Sarolaner (Simparica Trio) 5,803 reports · 11% of its reports
Didn't prevent heartworm after Febantel + Praziquantel + Pyrantel (Drontal Plus) 42 reports · 0.6% of its reports
Didn't prevent heartworm after Fenbendazole 65 reports · 1.1% of its reports
Didn't prevent heartworm after Pyrantel 79 reports · 1.7% of its reports

All reported side effects of Praziquantel + Pyrantel in dogs · Medicines most reported with didn't prevent heartworm