Amphotericin B 50 mg Ingredients and Usage

The active ingredient is Amphotericin B, a polyene antifungal antibiotic. The 50 mg strength is supplied as a lyophilized powder which must be reconstituted and then diluted for slow intravenous (IV) infusion.

Amphotericin B is indicated for the treatment of numerous systemic fungal infections, including:

• Invasive Aspergillosis: Fungal infection of the lungs and other organs.
• Cryptococcosis: Especially in patients with HIV/AIDS.
• Severe Systemic Candidiasis: Deep-seated Candida infections.
• Mucormycosis: A severe, rapidly progressing fungal infection often requiring aggressive treatment.

How Does Amphotericin B Work?

Amphotericin B is fungicidal (kills fungi) and works by disrupting the structural integrity of the fungal cell membrane. Its mechanism of action is highly dependent on its chemical structure:

1. Ergosterol Binding: Amphotericin B selectively binds to Ergosterol, a sterol molecule that is a major component of the fungal cell membrane (analogous to cholesterol in human cells).
2. Pore Formation: This binding creates pores or channels in the fungal cell membrane.
3. Cell Leakage: These pores allow essential molecules (like potassium ions and sugars) to leak out of the cell. The resulting loss of cellular contents and disruption of the cell’s osmotic balance rapidly leads to the death of the fungal organism.

Amphotericin B 50 mg Side Effects and Warnings

The conventional formulation of Amphotericin B is highly effective but associated with significant toxicity, leading to its nickname “Ampho-terrible.” Pre-medication (e.g., with antipyretics, antihistamines) is often necessary.

Black Box Warnings and Critical Precautions:

1. Infusion-Related Reactions: Nearly all patients experience acute reactions within the first hour of infusion, including high fever, severe shaking chills (rigors), headache, and nausea. These require slow infusion and pre-treatment to manage.
2. Nephrotoxicity (Kidney Damage): Amphotericin B can cause severe, dose-limiting acute kidney injury (AKI), often reversible but sometimes permanent. Close and frequent monitoring of serum creatinine, blood urea nitrogen (BUN), and electrolytes (especially potassium and magnesium) is mandatory. Patients often require extensive fluid hydration.
3. Anemia: The drug can cause normochromic, normocytic anemia, which may be severe.
4. Extravasation Risk: The infusion can cause irritation or damage to the vein (thrombophlebitis) and must be carefully administered.
5. Contraindication: The drug should not be used for common, non-invasive fungal infections where topical therapy is sufficient.

Amphotericin B 50 mg Storage Conditions

Amphotericin B is a light-sensitive powder that requires careful handling:

• Store the unopened vial of lyophilized powder in a refrigerator at a temperature between 2°C and 8°C (36°F and 46°F).
• Protect from Light: Keep the vial in the original carton to protect the powder from light exposure.
• Reconstitution: Must be reconstituted with Sterile Water for Injection (without bacteriostatic agents). Do not use saline for initial reconstitution.
• Dilution: The reconstituted solution must be immediately diluted in a 5% Dextrose injection solution (only). Saline or other electrolyte solutions will cause the drug to precipitate.
• The diluted solution should be used promptly.