Increased heart rate after Milbemycin Oxime + Praziquantel (Interceptor Plus) in dogs

64 reports to the FDA describe increased heart rate in dogs given Milbemycin Oxime + Praziquantel. That is 0.2% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

64Reports

63%Marked serious

34%Recovered

13%Died or euthanised

Same dayTypical onset

How soon it started

Same day

26 55%

1–2 days

1 2.1%

3–7 days

2 4.3%

1–4 weeks

3 6.4%

Over a month

15 32%

How the animals did

Recovered

22 34%

Still unwell when reported

25 39%

Died

3 4.7%

Euthanised

5 7.8%

Not known

9 14%

Problems reported at the same time

32 50%

30 47%

23 36%

19 30%

19 30%

Increased respiratory rate

13 20%

Liver problems

12 19%

Allergic reaction

12 19%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Milbemycin Oxime prevents heartworm and controls some intestinal worms (monthly). Praziquantel treats tapeworms.

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

Some herding breeds (for example Collies) carry the MDR1 gene variant and can be more sensitive to this drug class at high doses.

Questions owners ask

Can Milbemycin Oxime + Praziquantel cause increased heart rate in dogs?: 64 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).

Increased heart rate with similar medicines

Increased heart rate after Ivermectin + Pyrantel (Heartgard Plus) 53 reports · 0.0% of its reports
Increased heart rate after Milbemycin Oxime + Spinosad (Trifexis) 208 reports · 0.2% of its reports
Increased heart rate after Moxidectin (ProHeart 6) 77 reports · 0.2% of its reports
Increased heart rate after Ivermectin (Heartgard) 21 reports · 0.2% of its reports
Increased heart rate after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 32 reports · 0.4% of its reports

All reported side effects of Milbemycin Oxime + Praziquantel in dogs · Medicines most reported with increased heart rate