Chlorpheniramine — FDA Animal & Veterinary Adverse Event (ADE) Reports
Source: openFDA animalandveterinary/event.json, the FDA Center for Veterinary Medicine (CVM) adverse event report database. Data pulled 2026-07-22. Counts are report-level: one report may list multiple reactions and multiple animals, so figures are not additive and do not imply causation. Chlorpheniramine is a active ingredient.
Total reports
Chlorpheniramine: 190
Reports by species (top entries)
- Dog 134
- Cat 56
Top reported reactions (VEDDRA terms, top entries)
- Vomiting 29
- Lethargy (see also Central nervous system depression in 'Neurological') 23
- Other abnormal test result NOS 18
- Diarrhoea 17
- Emesis 14
- Anaemia NOS 13
- Weight loss 13
- Anorexia 12
- Decreased appetite 11
- Lack of efficacy - NOS 11
Source JSON: pdf-raw/ade/ade_active_ingredients_2026-07-22_b18.json (openFDA animalandveterinary/event.json, pulled 2026-07-22).