Drug profile

The FDA adverse-event record for Cyproheptadine

43 adverse-event reports submitted to the FDA Center for Veterinary Medicine reference Cyproheptadine. Species, reactions, and outcomes follow.

#1214 of 2,679
by report volume (all drugs)
43
adverse-event reports
20.9%
death-coded share
Cat
most-reported species
Verify with FDA CVM →

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Cyproheptadine ranks #1213 of 2679 by total reports (43). Death-coded-share rank requires at least 50 reports. National dual: Milbemycin Oxime + Spinosad is #1 of 2679 drugs by total adverse-event reports (149,624) at death-coded-share rank 965 of 1130 drugs with at least 50 reports (2.3%); separately, Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) is #1 highest death-coded share at 97.8% (report rank #821).

149,624
Milbemycin Oxime + Spinosad reports (#1)
97.8%
Atlantic Salmon Transgenic Whole (Opafp-Ghc2 Rdna Construct Inserted Into The A-Locus In The Eo-1A Lineage) death share (#1)
#1213
This drug, reports of 2679

Report volume reflects how common a breed or drug is and how often owners and vets file — not actual risk. Death-coded share ranks are limited to entries with enough reports to be meaningful. The two maps do not agree at #1.

Release-over-release change

What changed in the latest FDA data snapshot

PlainBreed reconstructed the prior snapshot from dated openFDA partitions through 2025 Q4, then compared it with the 2026-07-27 openFDA export. Cyproheptadine has 43 reports now versus 41 in that prior snapshot: 2 more (4.9%).

Report change
+2
Death-coded reports
+0
Death-coded share
−1.0 pts

This compares reported-event counts in two source snapshots. It does not establish a change in real-world risk, product safety, or disease incidence.

Subscribe to Cyproheptadine changes

Signature read: Cyproheptadine's 20.9% death-coded share is among the highest in the openFDA drug corpus.

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
43
Total Reports
9
Deaths Reported
20.9%
Death-coded share of reports

Active Ingredients

Cyproheptadine

Administration Routes

OralUnknownRectal

Species Affected

Cat 34
Dog 7
Horse 1
Human 1

Most Affected Breeds

Domestic Shorthair 16
Cat (unknown) 4
Domestic Longhair 4
Siamese 2
Cat (other) 2
Tonkinese 2
European 1
Crossbred Canine/dog 1
Thoroughbred 1
Shepherd Dog - German 1

Most Reported Reactions

Weight loss 12
Lack of efficacy - NOS 7
Vomiting 6
Ataxia 6
Anorexia 6
Death 5
Behavioural disorder NOS 5
Diarrhoea 5
Decreased appetite 5
Lethargy (see also Central nervous system depression in Neurological) 5
Lethargy (see also Central nervous system depression in 'Neurological') 4
Death by euthanasia 4

Outcome Breakdown

Outcome Unknown
14 (32.6%)
Ongoing
11 (25.6%)
Recovered/Normal
7 (16.3%)
Died
5 (11.6%)
Euthanized
4 (9.3%)
Recovered with Sequela
2 (4.7%)

Cyproheptadine: high death-coded share in the FDA AER row

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.

What to do with this drug

A report does not prove a drug caused the reaction; consult a veterinarian before acting on this data.

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

openFDA Animal & Veterinary Adverse Events (FDA CVM) for Cyproheptadine (#1214 of 2,679 by report volume); death-coded 20.9%. PlainBreed drug row · death-coded share stamp 20.9% · vintage 2025.

Informational only. FDA adverse-event reports are voluntary and do not prove causation; consult a veterinarian before acting on them. Verify with FDA CVM →