Drug profile

The FDA adverse-event record for Mitotane

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

41
adverse-event reports
9.8%
death-coded share
Dog
most-reported species
8
Lethargy (see also Central nervous system depression in 'Neurological') - top reaction
Verify with FDA CVM →
Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.
41
Total Reports
4
Deaths Reported
9.8%
Death Rate

Active Ingredients

Mitotane

Administration Routes

OralUnknown

Species Affected

Dog 41

Most Affected Breeds

Schnauzer (unspecified) 3
Lhasa Apso 3
Terrier - Yorkshire 3
Crossbred Canine/dog 3
Dog (unknown) 2
Shepherd Dog - German 2
Dachshund (unspecified) 2
Boxer (German Boxer) 2
Poodle - Miniature 2
Mastiff 2

Most Reported Reactions

Lethargy (see also Central nervous system depression in 'Neurological') 8
Elevated serum alkaline phosphatase (SAP) 7
Weight loss 6
Diarrhoea 6
Hypoadrenocorticism 6
Elevated alanine aminotransferase (ALT) 6
Seizure NOS 5
Underdose 4
Abnormal adrenocorticotropic hormone (ACTH) stimulation test 4
Pancreatitis 4
Decreased appetite 4
INEFFECTIVE, CUSHINGS 3

Outcome Breakdown

Outcome Unknown
15 (36.6%)
Ongoing
13 (31.7%)
Recovered/Normal
7 (17.1%)
Euthanized
3 (7.3%)
Recovered with Sequela
2 (4.9%)
Died
1 (2.4%)

Mitotane Adverse Event Insights

41 reports name Mitotane; 4 recorded a death outcome (9.8% of reported events, not a population-level mortality rate). Active ingredient: Mitotane. Administration routes: Oral, Unknown.

By species: Dog (41 reports). By breed: Schnauzer (unspecified) (3), Lhasa Apso (3), Terrier - Yorkshire (3).

Leading clinical signs: Lethargy (see also Central nervous system depression in 'Neurological') (8), Elevated serum alkaline phosphatase (SAP) (7), Weight loss (6), Diarrhoea (6). Outcome, 41 coded reports: Outcome Unknown leads at 36.6%.

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.