Restlessness or agitation after Diphenhydramine in dogs

167 reports to the FDA describe restlessness or agitation in dogs given Diphenhydramine. That is 3.5% of all reports for this medicine, compared with 1.6% across reports for all dog medicines, so it is reported unusually often with this medicine.

167Reports

52%Marked serious

38%Recovered

7.2%Died or euthanised

1 daysTypical onset

How soon it started

Same day

67 48%

1–2 days

23 17%

3–7 days

12 8.6%

1–4 weeks

13 9.4%

Over a month

24 17%

How the animals did

Recovered

60 36%

Recovered with lasting effects

3 1.8%

Still unwell when reported

57 34%

Died

9 5.4%

Euthanised

3 1.8%

Not known

35 21%

Problems reported at the same time

64 38%

53 32%

48 29%

44 26%

40 24%

36 22%

34 20%

29 17%

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 restlessness or agitation in dogs?: 167 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).

Restlessness or agitation with similar medicines

Restlessness or agitation after Melarsomine (Immiticide) 679 reports · 3.0% of its reports
Restlessness or agitation after Polysulfated Glycosaminoglycan 126 reports · 2.3% of its reports
Restlessness or agitation after Butorphanol 130 reports · 2.9% of its reports
Restlessness or agitation after Cefpodoxime 111 reports · 2.7% of its reports
Restlessness or agitation after Tramadol 131 reports · 3.5% of its reports
Restlessness or agitation after Florfenicol + Mometasone + Terbinafine 80 reports · 2.3% of its reports
Restlessness or agitation after Desoxycorticosterone Pivalate 82 reports · 2.5% of its reports
Restlessness or agitation after Propofol 60 reports · 2.0% of its reports
Restlessness or agitation after Dirlotapide 37 reports · 1.3% of its reports
Restlessness or agitation after Isoflurane 64 reports · 2.3% of its reports

All reported side effects of Diphenhydramine in dogs · Medicines most reported with restlessness or agitation