Home/Medicines/Posaconazole

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

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

Frequency

q12–24h

🐈

Cat

Limited feline data

Dose

5–10 mg/kg

Route

Frequency

q24h

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 →

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)

Educational reference only

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.

Educational reference only

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.

Educational reference only

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

Plumb's Veterinary Drug Handbook
Withrow & MacEwen's Small Animal Clinical Oncology
Merck Veterinary Manual
NRC Nutrient Requirements of Dogs and Cats
Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

ASPCA Animal Poison Control Center Guidelines
AAHA Diabetes Management Guidelines
ASPCA Poison Control Guidelines
RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

EPIC Study (J Vet Intern Med 2016)
JVIM FAT CAT Study

Regulatory & approvals — 1

CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

Washington State University VCPL MDR1 Database