Home Drug Guide Amphotericin B

Drug Guide

Generic Name

Amphotericin B

Brand Names Fungizone, Abelcet, Amphotec, Ambisome

Classification

Therapeutic: Antifungal

Pharmacological: Polyene antifungal

FDA Approved Indications

Serious systemic fungal infections caused by susceptible organisms, such as cryptococcal meningitis, histoplasmosis, blastomycosis, coccidioidomycosis, aspergillosis, and mucormycosis.

Mechanism of Action

Bind to ergosterol in fungal cell membranes, forming pores that increase membrane permeability, leading to leakage of cell contents and fungal cell death.

Dosage and Administration

Adult: Dosage varies based on formulation and severity; typically 0.3-1.5 mg/kg daily, administered via slow IV infusion.

Pediatric: Dosing based on weight and infection severity; generally similar to adult dosing.

Geriatric: Adjust as tolerated, with careful monitoring due to potential nephrotoxicity.

Renal Impairment: Use with caution; may require dose adjustments and monitoring of renal function.

Hepatic Impairment: No specific adjustment; however, monitor hepatic function as needed.

Pharmacokinetics

Absorption: Not absorbed orally; administered IV.

Distribution: Widely distributed; high affinity for renal tissue and liver.

Metabolism: Minimal metabolism; primarily remains unchanged (often eliminated via the kidneys).

Excretion: Mostly renal excretion of unchanged drug.

Half Life: 22-24 hours, but may be prolonged in renal impairment.

Contraindications

Hypersensitivity to Amphotericin B or other polyenes.

Precautions

Renal impairment, hepatic impairment, anemia, hypokalemia, hypomagnesemia, infusion-related reactions, and electrolyte imbalances. Use cautiously during pregnancy and lactation.

Adverse Reactions - Common

Fever, chills, rigor (Very common)
Nephrotoxicity (elevated serum creatinine, decreased renal function) (Common)
Hypokalemia, hypomagnesemia (Common)
Anemia (Common)

Adverse Reactions - Serious

Anaphylaxis (Rare)
Cardiac arrhythmias due to electrolyte disturbances (Rare)
Hepatotoxicity (Rare)
Severe infusion reactions including hypotension and shock (Rare)

Drug-Drug Interactions

Additive nephrotoxicity with aminoglycosides or cisplatin.
Enhancement of hypokalemia or hypomagnesemia with diuretics.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor renal function (serum creatinine, BUN), electrolytes, liver function, and infusion-related reactions.

Diagnoses:

Risk for renal impairment
Electrolyte imbalance
Acute infusion reaction

Implementation: Administer IV infusion slowly, premedicate as needed to reduce infusion reactions, and monitor patient closely.

Evaluation: Assess for improvement in infection signs, monitor labs regularly, and ensure electrolyte balance.

Patient/Family Teaching

Report any symptoms of allergic reaction, infusion reactions, or signs of renal impairment.
Maintain adequate hydration during therapy.
Stay on schedule for laboratory tests.

Special Considerations

Black Box Warnings:

Nephrotoxicity, infusion-related reactions, electrolyte imbalances, anemia.
Lipid-based formulations like AmBisome may have different toxicity profiles and dosing guidelines.

Genetic Factors: Not specifically relevant.

Lab Test Interference: May cause elevated serum creatinine and electrolyte abnormalities affecting lab interpretation.

Overdose Management

Signs/Symptoms: Severe nephrotoxicity, electrolyte disturbances, infusion reactions, hypotension.

Treatment: Discontinue drug, provide supportive care, manage electrolyte imbalances, and ensure adequate hydration.

Storage and Handling

Storage: Store vials at 2–8°C, protect from light.

Stability: Vary by formulation; follow manufacturer's instructions for storage.