Lethargy after Butorphanol in cats

The FDA has received 275 reports of lethargy in cats after Butorphanol. That is 12% of all reports for this medicine, compared with 14% across reports for all cat medicines.

275Reports
56%Marked serious
23%Recovered
26%Died or euthanised
1 daysTypical onset
SponsoredWorried about your pet? Ask a veterinarian online, 24/7

How soon it started

Same day
86 38%
1–2 days
78 35%
3–7 days
27 12%
1–4 weeks
22 9.8%
Over a month
11 4.9%

How the animals did

Recovered
62 23%
Still unwell when reported
83 30%
Died
37 13%
Euthanised
34 12%
Not known
59 21%

Problems reported at the same time

Age of the animals

Under 1 year
58
1–3 years
40
4–7 years
46
8–11 years
67
12+ years
53

About this medicine

Type: medicine.

Questions owners ask

Can Butorphanol cause lethargy in cats?
275 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).

Lethargy with similar medicines

All reported side effects of Butorphanol in cats · Medicines most reported with lethargy