Unable to rise after Diphenhydramine in dogs

The FDA has received 20 reports of unable to rise in dogs after Diphenhydramine. That is 0.4% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

20Reports

85%Marked serious

10%Recovered

45%Died or euthanised

1 daysTypical onset

How soon it started

Same day

7 44%

1–2 days

3 19%

3–7 days

3 19%

1–4 weeks

1 6.3%

Over a month

2 13%

How the animals did

Recovered

2 10%

Still unwell when reported

8 40%

Died

2 10%

Euthanised

7 35%

Not known

1 5.0%

Problems reported at the same time

9 45%

8 40%

8 40%

7 35%

7 35%

6 30%

5 25%

4 20%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Type: medicine.

Questions owners ask

Can Diphenhydramine cause unable to rise in dogs?: 20 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).

Unable to rise with similar medicines

Unable to rise after Polysulfated Glycosaminoglycan 46 reports · 0.8% of its reports
Unable to rise after Tramadol 45 reports · 1.2% of its reports
Unable to rise after Famotidine 21 reports · 0.8% of its reports
Unable to rise after Chondroitin + Glucosamine 29 reports · 1.1% of its reports
Unable to rise after Glucosamine 23 reports · 1.3% of its reports

All reported side effects of Diphenhydramine in dogs · Medicines most reported with unable to rise