Didn't work as expected after Fluoxetine in cats

The FDA has received 42 reports of didn't work as expected in cats after Fluoxetine. That is 17% of all reports for this medicine, compared with 8.7% across reports for all cat medicines, so it is reported unusually often with this medicine.

42Reports

29%Marked serious

17%Recovered

4.8%Died or euthanised

90 daysTypical onset

How soon it started

Same day

4 16%

1–2 days

0 0.0%

3–7 days

1 4.0%

1–4 weeks

3 12%

Over a month

17 68%

How the animals did

Recovered

5 12%

Recovered with lasting effects

2 4.8%

Still unwell when reported

12 29%

Euthanised

2 4.8%

Not known

21 50%

Problems reported at the same time

Loss of appetite

8 19%

Vomiting

7 17%

Administration error

5 12%

Behaviour change

4 9.5%

Inappropriate urination

3 7.1%

Weight loss

3 7.1%

Skin rash or irritation

3 7.1%

Itching

3 7.1%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Fluoxetine treats anxiety and behaviour problems.

Questions owners ask

Can Fluoxetine cause didn't work as expected in cats?: 42 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 90 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).

Didn't work as expected with similar medicines

Didn't work as expected after Gabapentin 248 reports · 13% of its reports

All reported side effects of Fluoxetine in cats · Medicines most reported with didn't work as expected