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Posaconazole

Prescription
Extended-Spectrum Triazole Antifungal
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
2 available
Interactions
3 documented
Formulations
3

Mechanism of action

Inhibits 14α-lanosterol demethylase in fungal ergosterol pathway. Broadest spectrum of the azole class including Aspergillus, Zygomycetes (Mucor), Fusarium, and most Candida. Structural analog of itraconazole.

At a glance

Class
Extended-Spectrum Triazole Antifungal
Schedule
Prescription
Storage
Suspension at room temperature; delayed-release tablets at room temperature; IV refrigerated

Dosing

🐕

Dog

Used for refractory or zygomycete infections (Mucor) where other azoles are inef
Dose
5–12 mg/kg
Route
PO
Frequency
q12–24h
🐈

Cat

Limited feline data
Dose
5–10 mg/kg
Route
PO
Frequency
q24h

Formulations

💊

Other — 3

Strength
—
Strength
—
Strength
—

Storage

Suspension at room temperature; delayed-release tablets at room temperature; IV refrigerated

Safety

Monitoring parameters

Hepatic enzymesCBCSerum posaconazole levels (TDM)Cardiac rhythm (QTc)

Interactions

Contraindicated — 1

Cisapride
contraindicated
CYP3A4 inhibition by posaconazole causes cisapride accumulation and fatal QT prolongation.
Management: NEVER combine.

Major — 2

Cyclosporine (Systemic)
major
Posaconazole potently inhibits CYP3A4, increasing cyclosporine levels 2-4 fold.
Management: Reduce cyclosporine dose by 50-75%. Monitor trough levels closely.
Phenobarbital
major
Phenobarbital induces CYP3A4, potentially reducing posaconazole levels. Also, posaconazole may inhibit phenobarbital metabolism.
Management: Monitor both drug levels. Antifungal efficacy may be reduced. Consider alternative anticonvulsant or antifungal.

Brands

Other markets

Noxafil
Posanol

FAQs

Frequently asked questions

›What is Posaconazole?
Posaconazole is a extended-spectrum triazole antifungal used in pets. Inhibits 14α-lanosterol demethylase in fungal ergosterol pathway. Broadest spectrum of the azole class including Aspergillus, Zygomycetes (Mucor), Fusarium, and most Candida. Structural analog of itraconazole.
›What is Posaconazole used for in pets?
Posaconazole is used in veterinary medicine for: Used for refractory or zygomycete infections (Mucor) where other azoles are inef; Limited feline data.
›What is the Posaconazole dose for dogs?
For dogs, Posaconazole is typically dosed as follows — Used for refractory or zygomycete infections (Mucor) where other azoles are inef: 5–12 mg/kg PO q12–24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Posaconazole dose for cats?
For cats, Posaconazole is typically dosed as follows — Limited feline data: 5–10 mg/kg PO q24h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›Does Posaconazole need a prescription?
Yes. Posaconazole is a prescription medication and should only be administered under veterinary supervision.

References

References

Textbooks & handbooks

  • Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
  • Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
  • Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
  • National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
  • The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/

Clinical guidelines & consensus

  • Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
  • American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.

Journals & peer-reviewed studies

  • Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
  • Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
  • ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control

Regulatory & approvals

  • Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/

Databases

  • Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →