What Is Amphotericin B? Uses, Dosage, and What You Need to Know in 2026

Amphotericin B is a polyene antifungal medication administered intravenously to treat serious, life-threatening fungal infections such as invasive aspergillosis, cryptococcal meningitis, mucormycosis, and systemic candidiasis.

What Is Amphotericin B?

Amphotericin B is one of the oldest and most potent antifungal drugs available. First introduced in the 1950s, it remains a critical tool for treating the most dangerous fungal infections — the kind that can't be managed with oral antifungals alone.

Here are the basics:

• Generic name: Amphotericin B
• Brand names: Fungizone (conventional), AmBisome (liposomal), Abelcet (lipid complex), Amphotec (cholesteryl sulfate complex)
• Drug class: Polyene antifungal
• Manufacturers: X-Gen Pharmaceuticals (conventional deoxycholate), Gilead/Astellas (AmBisome), Leadiant Biosciences (Abelcet)
• FDA approval: Yes — approved for multiple serious fungal infections
• Controlled substance: No — Amphotericin B is not a controlled substance

Amphotericin B comes in four formulations, and they're not interchangeable:

1. Amphotericin B Deoxycholate (Conventional) — The original formulation. Most affordable but has the most side effects, especially kidney toxicity. Supplied as a 50 mg vial of lyophilized powder for IV injection.
2. Amphotericin B Liposomal (AmBisome) — Wrapped in liposomes that reduce toxicity and improve delivery. Less kidney damage, fewer infusion reactions. 50 mg vial.
3. Amphotericin B Lipid Complex (Abelcet/ABLC) — Another lipid-based formulation. Available as a 5 mg/mL suspension (100 mg/20 mL vials).
4. Amphotericin B Cholesteryl Sulfate Complex (Amphotec) — Less commonly used. 50 mg and 100 mg vials.

What Is Amphotericin B Used For?

Amphotericin B is reserved for serious, potentially life-threatening fungal infections. It's not used for minor infections like athlete's foot or vaginal yeast infections. The FDA boxed warning specifically states it should only be used for progressive and potentially fatal fungal disease.

FDA-Approved Uses

• Invasive aspergillosis — Serious lung and systemic infections caused by Aspergillus species
• Cryptococcal meningitis — Fungal infection of the brain and spinal cord, particularly common in HIV/AIDS patients
• Systemic candidiasis — Candida infections that have entered the bloodstream
• Mucormycosis (zygomycosis) — Aggressive fungal infection often seen in diabetic or immunocompromised patients
• Blastomycosis — Severe cases requiring IV treatment
• Coccidioidomycosis — Valley fever with disseminated disease
• Histoplasmosis — Disseminated infection
• Sporotrichosis — Severe, systemic cases
• Visceral leishmaniasis — Liposomal formulation is FDA-approved for this parasitic infection
• Empirical antifungal therapy — Liposomal formulation is used in febrile neutropenic patients who don't respond to antibacterial antibiotics

Off-Label Uses

• COVID-19-associated mucormycosis
• Fusarium infections
• Aerosolized prophylaxis in immunocompromised patients (lung transplant, leukemia)
• Bladder irrigation for Candida cystitis
• Intravitreal injection for fungal endophthalmitis

How Is Amphotericin B Taken?

Amphotericin B is not a pill. It is administered intravenously (through an IV) in a hospital or infusion center. Here's what treatment looks like:

• Administration: IV infusion, typically over 2–6 hours
• Setting: Hospital inpatient, outpatient infusion center, or ICU
• Typical dose range:Conventional deoxycholate: 0.5–1.5 mg/kg/day
• Liposomal (AmBisome): 3–6 mg/kg/day
• Lipid complex (Abelcet): 5 mg/kg/day

Duration: Days to weeks depending on the infection type and severityPre-medication: Acetaminophen, diphenhydramine (Benadryl), and sometimes hydrocortisone are given before each infusion to prevent fever, chills, and other reactionsPre-hydration: Normal saline IV hydration before infusion helps protect the kidneys

You cannot take Amphotericin B orally — it is not absorbed through the digestive system. For more on what happens during treatment and managing reactions, see our guide on Amphotericin B side effects.

Who Should Not Take Amphotericin B?

Amphotericin B is contraindicated in the following situations:

• Known allergy or anaphylactic reaction to Amphotericin B or any component of the formulation
• Non-invasive fungal infections in patients with normal immune function (e.g., oral thrush, vaginal candidiasis) — the risks outweigh benefits for minor infections

Use with extra caution in:

• Patients with existing kidney disease
• Patients with heart disease or arrhythmias
• Patients with diabetes
• Patients with electrolyte imbalances
• Patients receiving other nephrotoxic medications (see drug interactions)
• Pregnant patients (Category B — use only when clearly needed)
• Breastfeeding patients (generally not recommended)

How Much Does Amphotericin B Cost?

The cost of Amphotericin B varies dramatically depending on which formulation is used:

• Conventional Amphotericin B Deoxycholate: Approximately $49–$70 per 50 mg vial
• Liposomal Amphotericin B (AmBisome): Approximately $300+ per 50 mg vial
• Lipid Complex (Abelcet): $300–$1,200+ per vial

A full treatment course can cost anywhere from $5,000 to $50,000 or more depending on the formulation, dose, and duration.

Amphotericin B is typically covered under your medical benefit (not pharmacy benefit) since it's administered in a hospital setting. Prior authorization is common, especially for the more expensive lipid formulations. There are currently no manufacturer savings programs or copay cards available for Amphotericin B.

For patients facing financial hardship, organizations like NeedyMeds, RxAssist, and hospital financial assistance programs may be able to help. Read our full guide on saving money on Amphotericin B.

Final Thoughts

Amphotericin B remains an essential medication for the most serious fungal infections — the kind where no other drug will do. While its side effect profile requires careful monitoring and its cost can be significant, it saves lives when used appropriately under specialist supervision.

If you or a loved one needs Amphotericin B, understanding the different formulations, the treatment process, and the current shortage situation will help you navigate the process. For help finding this medication or a prescribing specialist, visit Medfinder.