Amphotericin B
Also known as: Abelcet, AmBisome, Amphotec, Fungizone, Amphocil
Amphotericin B is a powerful antifungal medication used only for **serious, life-threatening fungal infections**. - **Administration:** It must be given by injection (usually IV), which often requires your pet to be hospitalized or make frequent visits to the clinic. - **Kidney Risks:** This drug is highly toxic to the kidneys. Most pets will experience some degree of kidney stress. We will perform frequent blood and urine tests to monitor kidney function closely. - **Side Effects:** Watch for signs of illness such as vomiting, loss of appetite, extreme lethargy, or fever. Contact your veterinarian immediately if these occur. - **Cost & Commitment:** Treatment can be expensive and requires a significant time commitment for monitoring and administration.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Susceptible systemic fungal infections (Llama)
- Susceptible systemic fungal infections (Rapid-Infusion Technique)
- Susceptible systemic fungal infections (Slow IV Infusion Technique)
- Systemic fungal infections (Dehydrated/compromised)
- Systemic mycoses (Lipid-based: AmBisome, Amphocil, Abelcet)
- Systemic mycoses (ABLC; Abelcet)
- Blastomycosis
- Blastomycosis
- Blastomycosis (severe cases, using Abelcet)
- Cryptococcosis
- Histoplasmosis
- Histoplasmosis
- Leishmaniasis (Liposomal form)
How it is given
Possible side effects
- Nephrotoxicity (very common, dose-dependent)
- Anorexia and vomiting
- Hypokalemia and hypomagnesemia
- Distal renal tubular acidosis
- Phlebitis at injection site
- Cardiac arrhythmias
- Non-regenerative anemia
- Fever (can be mitigated with NSAIDs or low-dose steroids)
- Tachycardia, tachypnea, lethargy, restlessness (horses)
- Calcinosis cutis (dogs)
Cautions & contraindications
- Patients with known hypersensitivity to amphotericin B (unless the infection is life-threatening and no alternatives exist)
- > **Black Box Warning Equivalent:** Amphotericin B is highly nephrotoxic. Renal function must be aggressively monitored during therapy. - Use with extreme caution in patients with pre-existing renal disease. - Cats are more sensitive to nephrotoxic effects; reduced dosages are often recommended. - Ensure adequate hydration prior to administration. Sodium loading (e.g., normal saline administration before and after dosing) may help avert renal insufficiency by preventing tubuloglomerular feedback-induced vasoconstriction. - Pregnancy: Weigh risks vs. benefits. FDA Category B (human); Papich Class A (veterinary).
Drug interactions
- Corticosteroids: May exacerbate the potassium-losing effects of amphotericin B.
- Digoxin: Amphotericin B-induced hypokalemia may exacerbate digoxin toxicity.
- Flucytosine: In vitro synergy against Cryptococcus and Candida, but may also increase flucytosine toxicity.
- Nephrotoxic Drugs (Aminoglycosides, Polymyxin B, Cisplatin, Cyclosporine, etc.): Additive renal toxicity; avoid concurrent or sequential use if possible.
- Potassium-Depleting Drugs (Thiazide or Loop Diuretics): Increased risk of severe hypokalemia.
- Saline Solutions or Preservative-containing Solutions: Reconstituting amphotericin B deoxycholate with these solutions may cause precipitation.
- Skeletal Muscle Relaxants (Tubocurarine): Amphotericin B-induced hypokalemia may enhance curariform effects.
- Fluorouracil: Amphotericin may increase the toxic effects of fluorouracil.
- Doxorubicin: Amphotericin may increase the toxic effects of doxorubicin.
- Methotrexate: Amphotericin may increase the toxic effects of methotrexate.
Frequently asked questions
What is Amphotericin B used for in pets?
Amphotericin B is a powerful antifungal medication used only for **serious, life-threatening fungal infections**. - **Administration:** It must be given by injection (usually IV), which often requires your pet to be hospitalized or make frequent visits to the clinic. - **Kidney Risks:** This drug is highly toxic to the kidneys. Most pets will experience some degree of kidney stress. We will perform frequent blood and urine tests to monitor kidney function closely. - **Side Effects:** Watch for signs of illness such as vomiting, loss of appetite, extreme lethargy, or fever. Contact your veterinarian immediately if these occur. - **Cost & Commitment:** Treatment can be expensive and requires a significant time commitment for monitoring and administration.
Is Amphotericin B safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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