Drug profile

The FDA adverse-event record for Primidone

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

#1600 of 2,679
by report volume (all drugs)
25
adverse-event reports
8.0%
death-coded share
Dog
most-reported species
Verify with FDA CVM →

Corpus placement

According to the FDA Center for Veterinary Medicine openFDA adverse-event extract, Primidone ranks #1577 of 2679 by total reports (25). 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)
#1577
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. Primidone has 25 reports now versus 25 in that prior snapshot: 0 the same number of (0.0%).

Report change
+0
Death-coded reports
+0
Death-coded share
+0.0 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 Primidone changes

Signature read: death-coded report count at 2 is the most distinctive stamp on Primidone's FDA AER row.

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
25
Total Reports
2
Deaths Reported
8.0%
Death-coded share of reports

Active Ingredients

Primidone

Administration Routes

OralUnknown

Species Affected

Dog 24
Human 1

Most Affected Breeds

Crossbred Canine/dog 6
Retriever - Labrador 3
Spaniel - Cocker American 2
Retriever - Golden 2
Shepherd Dog - Australian 2
Weimaraner 1
Schnauzer (unspecified) 1
Pug 1
Pekingese 1
Terrier - Bull - Staffordshire 1

Most Reported Reactions

Elevated serum alkaline phosphatase (SAP) 6
Ataxia 4
Elevated alanine aminotransferase (ALT) 4
Polydipsia 3
Apprehension 3
Pacing 3
Elevated bile acids 3
Hyperactivity 3
Seizure NOS 3
Lameness 2
Polyphagia 2
WBC, URINE 2

Outcome Breakdown

Outcome Unknown
2 (40.0%)
Died
1 (20.0%)
Euthanized
1 (20.0%)
Recovered/Normal
1 (20.0%)

Primidone Adverse Event Insights

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 Primidone (#1600 of 2,679 by report volume); death-coded 8.0%. PlainBreed drug row · death-coded report count stamp 2 · 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 →