Allergic reaction after Milbemycin Oxime + Praziquantel (Interceptor Plus) in dogs

The FDA has received 402 reports of allergic reaction in dogs after Milbemycin Oxime + Praziquantel. That is 1.3% of all reports for this medicine, compared with 2.3% across reports for all dog medicines, so it is reported less often than average with this medicine.

402Reports

42%Marked serious

46%Recovered

3.2%Died or euthanised

3 daysTypical onset

How soon it started

Same day

105 36%

1–2 days

40 14%

3–7 days

15 5.1%

1–4 weeks

29 9.9%

Over a month

105 36%

How the animals did

Recovered

184 46%

Still unwell when reported

120 30%

Died

11 2.7%

Euthanised

2 0.5%

Not known

85 21%

Problems reported at the same time

131 33%

111 28%

80 20%

70 17%

45 11%

42 10%

41 10%

37 9.2%

Age of the animals

Under 1 year

1–3 years

139

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 allergic reaction in dogs?: 402 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 3 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).

Allergic reaction with similar medicines

Allergic reaction after Ivermectin + Pyrantel (Heartgard Plus) 788 reports · 0.5% of its reports
Allergic reaction after Milbemycin Oxime + Spinosad (Trifexis) 1,103 reports · 0.9% of its reports
Allergic reaction after Moxidectin (ProHeart 6) 9,936 reports · 20% of its reports
Allergic reaction after Milbemycin Oxime (Interceptor) 274 reports · 0.9% of its reports
Allergic reaction after Selamectin (Revolution) 473 reports · 1.6% of its reports
Allergic reaction after Ivermectin (Heartgard) 160 reports · 1.3% of its reports
Allergic reaction after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 70 reports · 0.8% of its reports

All reported side effects of Milbemycin Oxime + Praziquantel in dogs · Medicines most reported with allergic reaction