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Source overview
Recorded excerpts for one species. Each dose remains a separate source entry; no regimen is selected.
Choose one species to view its source overview. All-species evidence remains available below.
View full clinical evidence and sources ↓Clinical evidence
Pending clinical review (PROPOSED)Rule-based (RULE_BASED)— applies to the facts and dose entries in this species selection; individual source records retain their own status.
Indications2
Pituitary-dependent and adrenal-dependent hyperadrenocorticism (Cushing's), Alopecia X
DogOn-label (ON_LABEL)1 source record · View provenance
- Dog · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Indications table · Not applicable · On-label (ON_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Original excerpt: Pituitary-dependent and adrenal-dependent hyperadrenocorticism (Cushing's), Alopecia X — Authorized (FDA, Vetoryl)
- Dog · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Indications table · Not applicable · On-label (ON_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Feline hyperadrenocorticism
CatExtra-label (EXTRA_LABEL)1 source record · View provenance
- Cat · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Indications table · Not applicable · Extra-label (EXTRA_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Original excerpt: Feline hyperadrenocorticism — Extra-label
- Cat · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Indications table · Not applicable · Extra-label (EXTRA_LABEL) · Pending clinical review (PROPOSED) · Rule-based
Dose regimens4
This calculator performs arithmetic only on the sourced dosing field shown for each result — it does not verify the field's accuracy, does not select which field to use for a patient, and does not replace a veterinarian's order. Not for clinical use. Confirm every result against the primary source before dispensing.
Choose one species above to view its dose calculator.
Adverse effects144
Lethargy, inappetence, vomiting, diarrhea, mild electrolyte changes — Up to 63% of dogs, usually early and self-limiting
DogNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Dog · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Side Effects / Adverse Effects table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Adrenal necrosis, hypoadrenocorticism, death — Rare but serious — can be irreversible
DogNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Dog · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Side Effects / Adverse Effects table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Generally well tolerated — —
CatHorseNot applicable (NOT_APPLICABLE)2 source records · View provenance
- Cat · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Side Effects / Adverse Effects table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
- Horse · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Side Effects / Adverse Effects table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
These are counts of spontaneously reported events, not proven adverse effects, causal relationships, or incidence rates.
Bars compare report counts within each species; they do not show incidence.
More reportsFewer reportsDog
- Vomiting1,992 reports
- Lethargy (see also Central nervous system depression in 'Neurological')1,973 reports
- Hyperkalaemia1,741 reports
- Elevated serum alkaline phosphatase (SAP)1,687 reports
- Weight loss1,478 reports
- Underdose1,430 reports
- Diarrhoea1,422 reports
- Elevated alanine aminotransferase (ALT)1,372 reports
- Elevated blood urea nitrogen (BUN)1,121 reports
- Decreased appetite1,095 reports
- Anorexia1,085 reports
- INEFFECTIVE, CUSHINGS977 reports
Cat
- Decreased appetite3 reports
- Abnormal ultrasound finding2 reports
- Accidental exposure2 reports
- Anisocoria2 reports
- Behavioural disorder NOS2 reports
- Death by euthanasia2 reports
- Drug prescribing error2 reports
- Hyperglycaemia2 reports
- Vomiting2 reports
- Abnormal radiograph finding1 reports
- Adrenal gland disorder NOS1 reports
- Azotaemia1 reports
Monitoring2
ACTH stimulation test 10–14 days after starting/each dose change, then q3 months once stable — perform 4–6h post-dose; serum electrolytes; clinical signs (PU/PD, appetite, skin)
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Monitoring Parameters · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Target post-ACTH cortisol: 1.45–5.4 mcg/dL (40–150 nmol/L)
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Monitoring Parameters · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Contraindications1
Hypersensitivity; do not use in pregnant dogs or animals intended for breeding; renal/hepatic disease
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Contraindications & Warnings table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Precautions4
Will not shrink adrenal tumors (adrenals may enlarge during treatment despite clinical improvement)
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Contraindications & Warnings table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Watch closely in the first 10–14 days for signs of over-suppression (lethargy, vomiting, inappetence) — these can herald acute hypoadrenocorticism/adrenal necrosis; if suspected, stop the drug and give supplemental glucocorticoids.
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Clinical pearl · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Not more effective than mitotane per some clinicians' experience, and can be less predictable — the two remain roughly comparable in survival outcomes but require different monitoring approaches.
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Clinical pearl · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Give with food — improves consistency of absorption.
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Clinical pearl · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Interactions2
ACE inhibitors, potassium-sparing diuretics (spironolactone), potassium supplements — ↑ hyperkalemia risk
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Drug Interactions table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Ketoconazole, mitotane, aminoglutethimide — May potentiate trilostane's effect → hypoadrenocorticism risk
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Drug Interactions table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Pharmacokinetics4
Bioavailability — Rapid but erratic oral absorption
Other speciesNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Other species · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Pharmacokinetics table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Duration — Cortisol suppression lasts ≤20h, often wanes by 10h
Other speciesNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Other species · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Pharmacokinetics table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Metabolism — Hepatic → active metabolite ketotrilostane
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Pharmacokinetics table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Elimination — Returns to baseline by ~18h
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Pharmacokinetics table · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Pregnancy / lactation considerations1
Contraindicated in pregnancy — significantly reduces progesterone synthesis. Reportedly FDA category X (unconfirmed). Milk data not located — use with caution if nursing.
Species not recordedNot applicable (NOT_APPLICABLE)1 source record · View provenance
- Species not recorded · Plumb's Veterinary Drug Handbook, 7th ed., p. 1145–1147; Saunders Handbook of Veterinary Drugs (Papich), 4th ed., p. 813–815 — Pregnancy & Lactation · Not applicable · Not applicable (NOT_APPLICABLE) · Pending clinical review (PROPOSED) · Rule-based
Literature references12
References are linked to this drug. Species applicability is not recorded here, so the species filter does not narrow this list. Imported dates do not retain their original precision; confirm dates in the original citation.
- Clinical Findings, Treatment Recommendations, and Outcome in Dogs Following Ingestion of a Single Unintended Dose of Trilostane: 403 Cases (2008-2023).
Study summary not available in the imported record. Open the original citation to review the study.
- Enterocutaneous fistula as a long-term complication of jejunostomy tube placement in a dog with hyperadrenocorticism.
Study summary not available in the imported record. Open the original citation to review the study.
- Association between post-ACTH cortisol and trilostane dosage in dogs with pituitary-dependent hypercortisolism.
Study summary not available in the imported record. Open the original citation to review the study.
- Progesterone modulates HSD11B1-mediated cortisol production in luteinized bovine granulosa cells.
Study summary not available in the imported record. Open the original citation to review the study.
- Adrenocortical hypoperfusion detected by contrast-enhanced ultrasound in a dog with trilostane-induced hypoadrenocorticism.
Study summary not available in the imported record. Open the original citation to review the study.
Sources: PubMed, National Library of Medicine; openFDA, U.S. Food and Drug Administration; Plumb DC. Plumb's Veterinary Drug Handbook. 7th ed. PharmaVet Inc; 2011.
Owner information handout
Plain-language medication information to review with the owner. Open the handout to print it or download a PDF.
Available products
Products listed in the Health Canada Drug Product Database for this active ingredient. A listing does not establish that a product is authorized for the clinical uses described on this page.