Medication error after Milbemycin Oxime + Spinosad (Trifexis) in dogs

47 reports to the FDA describe medication error in dogs given Milbemycin Oxime + Spinosad. That is 0.0% of all reports for this medicine, compared with 0.6% across reports for all dog medicines, so it is reported less often than average with this medicine.

47Reports
15%Marked serious
26%Recovered
0.0%Died or euthanised
Same dayTypical onset
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How soon it started

Same day
26 70%
1–2 days
3 8.1%
3–7 days
0 0.0%
1–4 weeks
2 5.4%
Over a month
6 16%

How the animals did

Recovered
12 26%
Still unwell when reported
10 21%
Not known
25 53%

Problems reported at the same time

Age of the animals

Under 1 year
7
1–3 years
19
4–7 years
6
8–11 years
9
12+ years
4

About this medicine

Milbemycin Oxime prevents heartworm and controls some intestinal worms (monthly). Spinosad kills fleas; monthly chewable.

Products with this combination include Trifexis. 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 + Spinosad cause medication error in dogs?
47 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).

Medication error with similar medicines

All reported side effects of Milbemycin Oxime + Spinosad in dogs · Medicines most reported with medication error