Tremors after Eprinomectin + Esafoxolaner + Praziquantel (NexGard Combo) in cats

The FDA has received 218 reports of tremors in cats after Eprinomectin + Esafoxolaner + Praziquantel. That is 6.7% of all reports for this medicine, compared with 2.6% across reports for all cat medicines, so it is reported unusually often with this medicine.

218Reports
51%Marked serious
33%Recovered
28%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
85 40%
1–2 days
84 40%
3–7 days
18 8.6%
1–4 weeks
18 8.6%
Over a month
5 2.4%

How the animals did

Recovered
70 32%
Recovered with lasting effects
1 0.5%
Still unwell when reported
24 11%
Died
22 10%
Euthanised
39 18%
Not known
62 28%

Problems reported at the same time

Age of the animals

Under 1 year
69
1–3 years
74
4–7 years
30
8–11 years
25
12+ years
18

About this medicine

Eprinomectin controls worms and prevents heartworm. Esafoxolaner kills fleas and ticks (spot-on for cats). Praziquantel treats tapeworms.

Products with this combination include NexGard Combo. 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 Eprinomectin + Esafoxolaner + Praziquantel cause tremors in cats?
218 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 1 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).

Tremors with similar medicines

All reported side effects of Eprinomectin + Esafoxolaner + Praziquantel in cats · Medicines most reported with tremors