Discomfort after Diphenhydramine in dogs

The FDA has received 36 reports of discomfort in dogs after Diphenhydramine. That is 0.8% 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.

36Reports

56%Marked serious

11%Recovered

2.8%Died or euthanised

1 daysTypical onset

How soon it started

Same day

15 48%

1–2 days

5 16%

3–7 days

1 3.2%

1–4 weeks

4 13%

Over a month

6 19%

How the animals did

Recovered

4 11%

Still unwell when reported

18 50%

Died

1 2.8%

Not known

13 36%

Problems reported at the same time

13 36%

13 36%

13 36%

12 33%

Injection site reaction

12 33%

Diarrhea

11 31%

Dehydration

9 25%

Pain

8 22%

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 discomfort in dogs?: 36 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).

Discomfort with similar medicines

Discomfort after Melarsomine (Immiticide) 68 reports · 0.3% of its reports
Discomfort after Butorphanol 35 reports · 0.8% of its reports
Discomfort after Tramadol 25 reports · 0.7% of its reports
Discomfort after Famotidine 21 reports · 0.8% of its reports
Discomfort after Tigilanol Tiglate 59 reports · 2.9% of its reports

All reported side effects of Diphenhydramine in dogs · Medicines most reported with discomfort