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Amphotericin B

Prescription

Polyene antifungal

Last reviewed 19 Apr 2026 · PetCare.AI Editorial Team

Species

Dog, Cat

Brands

3 available

Interactions

5 documented

Formulations

Mechanism of action

Binds to ergosterol in fungal cell membranes, creating pores that disrupt membrane integrity and cause cell death

At a glance

Class

Polyene antifungal

Schedule

Prescription

Storage

Refrigerate at 2–8°C; reconstituted solution protect from light, use within 24h

Dosing

🐕

Dog

Systemic fungal infections (blastomycosis, histoplasmosis, coccidioidomycosis)

Dose

0.25–1 mg/kg

Route

Frequency

Every 48h (MWF protocol)

Max dose

50 mg

Duration: Cumulative dose 4–12 mg/kg total

🐈

Cat

Systemic fungal infections (cryptococcosis)

Dose

0.25–0.5 mg/kg

Route

Frequency

Every 48h

Max dose

5 mg

Duration: Cumulative dose 4–8 mg/kg total

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

💉

Powder for injection — 1

Strength

50mg vial

Available in India

Storage

Refrigerate at 2–8°C; reconstituted solution protect from light, use within 24h

Safety

Absolute contraindications — do not use

Renal failure
Highly nephrotoxic

Use with caution

Concurrent nephrotoxic drugs
Additive nephrotoxicity

Adverse effects

Common

Nephrotoxicity

Nausea

Vomiting

Fever

Serious

Acute renal failure

Hypokalemia

Cardiac arrhythmias

Monitoring parameters

BUN/Creatinine before each doseSerum potassiumPCV

Educational reference only

Interactions

Contraindicated — 2

Gentamicin

contraindicated

Both are nephrotoxic; combined use causes additive/synergistic renal damage

Management: Avoid concurrent use. If both required, use sequential therapy with renal monitoring between courses.

Gentamicin (Systemic)

contraindicated

Both are directly nephrotoxic: amphotericin B damages renal tubular cell membranes; gentamicin accumulates in proximal tubular lysosomes. Combined: severe irreversible renal failure.

Management: NEVER combine. If both antifungal and aminoglycoside needed, use fluconazole/itraconazole instead of amphotericin, or use different antibiotic class.

Major — 2

Furosemide

major

Furosemide potentiates amphotericin B nephrotoxicity through renal vasoconstriction and electrolyte depletion

Management: Avoid concurrent use. Ensure aggressive fluid therapy during amphotericin B administration.

Meloxicam

major

NSAID prostaglandin inhibition reduces renal blood flow + amphotericin direct tubular toxicity: synergistic nephrotoxicity.

Management: Avoid NSAIDs during amphotericin therapy. Use opioids for pain management.

Moderate — 1

Flucytosine

moderate

Amphotericin B damages renal tubular cells, reducing flucytosine clearance (renally eliminated) and increasing myelosuppression risk. However, amphotericin B also enhances flucytosine uptake by fungi (synergistic antifungal effect).

Management: Intentional therapeutic combination for cryptococcosis and systemic candidiasis. Monitor flucytosine levels (target 25-100 mcg/mL), renal function, and CBC closely.

Educational reference only

Brands

International

Fungizone

Bristol-Myers Squibb

India

Amphocil

Bharat Serums

Amfocan

Sun Pharma

FAQs

Frequently asked questions

›What is Amphotericin B?

Amphotericin B is a polyene antifungal used in pets. Binds to ergosterol in fungal cell membranes, creating pores that disrupt membrane integrity and cause cell death

›What is Amphotericin B used for in pets?

Amphotericin B is used in veterinary medicine for: Systemic fungal infections (blastomycosis, histoplasmosis, coccidioidomycosis); Systemic fungal infections (cryptococcosis).

›What is the Amphotericin B dose for dogs?

For dogs, Amphotericin B is typically dosed as follows — Systemic fungal infections (blastomycosis, histoplasmosis, coccidioidomycosis): 0.25–1 mg/kg IV Every 48h (MWF protocol). Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What is the Amphotericin B dose for cats?

For cats, Amphotericin B is typically dosed as follows — Systemic fungal infections (cryptococcosis): 0.25–0.5 mg/kg IV Every 48h. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.

›What are the side effects of Amphotericin B?

Common: Nephrotoxicity, Nausea, Vomiting, Fever. Serious (call your vet immediately): Acute renal failure, Hypokalemia, Cardiac arrhythmias.

›Does Amphotericin B need a prescription?

Yes. Amphotericin B is a prescription medication and should only be administered under veterinary supervision.

›When should Amphotericin B not be used?

Do not use Amphotericin B if: Renal failure.

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

Related medicines

Other medicines in the same class (Polyene antifungal).

Nystatin

Binds to ergosterol in fungal cell membranes, creating pores that increase membrane permeability, leading to leakage of intracellular contents and cell death

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