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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
1

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
IV
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
IV
Frequency
Every 48h
Max dose
5 mg
Duration: Cumulative dose 4–8 mg/kg total

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

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.

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.

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 →

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