Drug profile

The FDA adverse-event record for Chlorpheniramine

186 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Chlorpheniramine. See the species affected, top reactions, and outcomes below.

186
adverse-event reports
10.8%
death-coded share
Dog
most-reported species
28
Vomiting - top reaction
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Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
186
Total Reports
20
Deaths Reported
10.8%
Death Rate

Active Ingredients

Chlorpheniramine

Administration Routes

OralUnknownTransdermalTopicalSubcutaneous

Species Affected

Dog 132
Cat 54

Most Affected Breeds

Domestic Shorthair 43
Chihuahua 12
Maltese 12
Retriever - Labrador 9
Terrier - Yorkshire 7
Retriever - Golden 6
Shepherd Dog - German 6
Boxer (German Boxer) 5
Domestic Longhair 4
Lhasa Apso 4

Most Reported Reactions

Vomiting 28
Lethargy (see also Central nervous system depression in 'Neurological') 23
Other abnormal test result NOS 18
Diarrhoea 17
Anaemia NOS 15
Emesis 14
Weight loss 12
Decreased appetite 11
Death by euthanasia 10
Anorexia 10
Inappetence 9
Seizure NOS 9

Outcome Breakdown

Ongoing
79 (42.5%)
Recovered/Normal
61 (32.8%)
Outcome Unknown
26 (14.0%)
Died
10 (5.4%)
Euthanized
10 (5.4%)

Chlorpheniramine Adverse Event Insights

186 reports name Chlorpheniramine; 20 recorded a death outcome (10.8% of reported events, not a population-level mortality rate). Active ingredient: Chlorpheniramine. Administration routes: Oral, Unknown, Transdermal, Topical.

By species: Dog (132 reports), Cat (54 reports). By breed: Domestic Shorthair (43), Chihuahua (12), Maltese (12).

Leading clinical signs: Vomiting (28), Lethargy (see also Central nervous system depression in 'Neurological') (23), Other abnormal test result NOS (18), Diarrhoea (17). Outcome, 186 coded reports: Ongoing leads at 42.5%.

Read these counts as reporting volume, not risk: per our methodology, a widely-prescribed drug will rack up more raw FDA reports in a given year than a rarely-used one at an identical true rate, so we recommend comparing within similar-exposure products rather than across the full 2025 catalog.

Source: FDA Center for Veterinary Medicine openFDA Animal & Veterinary Adverse Events (CVM AER) · 2025

Every figure on PlainBreed is rendered directly from FDA openFDA adverse event data, no number is typed in by an editor. This page draws directly on FDA openFDA data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.