Urine abnormalities after Diphenhydramine in dogs

The FDA has received 33 reports of urine abnormalities in dogs after Diphenhydramine. That is 0.7% of all reports for this medicine, compared with 0.2% across reports for all dog medicines, so it is reported unusually often with this medicine.

33Reports

64%Marked serious

15%Recovered

27%Died or euthanised

8 daysTypical onset

How soon it started

Same day

6 23%

1–2 days

3 12%

3–7 days

4 15%

1–4 weeks

8 31%

Over a month

5 19%

How the animals did

Recovered

5 15%

Still unwell when reported

15 45%

Died

6 18%

Euthanised

3 9.1%

Not known

4 12%

Problems reported at the same time

18 55%

17 52%

16 48%

14 42%

12 36%

11 33%

9 27%

9 27%

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 urine abnormalities in dogs?: 33 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 8 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).

Urine abnormalities with similar medicines

Urine abnormalities after Melarsomine (Immiticide) 32 reports · 0.1% of its reports
Urine abnormalities after Polysulfated Glycosaminoglycan 24 reports · 0.4% of its reports
Urine abnormalities after Butorphanol 24 reports · 0.5% of its reports
Urine abnormalities after Cefpodoxime 38 reports · 0.9% of its reports
Urine abnormalities after Tramadol 55 reports · 1.5% of its reports
Urine abnormalities after Isoflurane 20 reports · 0.7% of its reports
Urine abnormalities after Cephalexin 22 reports · 0.8% of its reports
Urine abnormalities after Famotidine 52 reports · 2.0% of its reports
Urine abnormalities after Chondroitin + Glucosamine 35 reports · 1.3% of its reports
Urine abnormalities after Glucosamine 29 reports · 1.6% of its reports

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