How to administer Ambisome (amphotericin B liposomal)

Administration of AmBisome (Liposomal Amphotericin B)

Liposomal amphotericin B (AmBisome) should be administered intravenously at a dose of 3-5 mg/kg daily for standard fungal infections, with premedication to prevent infusion-related reactions and adequate hydration to minimize nephrotoxicity. 1, 2

Preparation and Administration

• Reconstitute AmBisome by adding 12 mL of sterile water for injection to each 50 mg vial, creating a concentration of 4 mg/mL 2
• Shake the vial vigorously for at least 30 seconds until all material is completely dispersed 3
• Further dilute the reconstituted solution with 5% dextrose injection to a final concentration of 1-2 mg/mL before administration 2
• Administer through an in-line filter with a mean pore diameter of 1.0 micron or larger 3
• Infuse over 1-2 hours; longer infusion times may be used for patients who experience infusion-related reactions 1

Premedication and Hydration

• Administer premedication with diphenhydramine or acetaminophen 30 minutes before infusion to reduce infusion-related reactions 2, 3
• Provide 1 L of normal saline (0.9%) intravenously before AmBisome infusion to reduce nephrotoxicity in patients who can tolerate the fluid volume 1, 2
• Consider additional 1 L of normal saline after infusion to further minimize nephrotoxicity 2

Dosing by Indication

• For cryptococcal meningitis: 4-6 mg/kg daily 4
• For severe or life-threatening fungal infections: 5 mg/kg daily 1
• For CNS involvement: Higher doses of 5-10 mg/kg daily may be required 2
• For children with cryptococcal meningitis: 2 mg/kg daily, with doses up to 7.5 mg/kg daily for refractory cases 4

Monitoring During Therapy

• Monitor renal function, electrolytes, and liver function tests regularly 1, 3
• Watch for infusion-related reactions including chest pain, dyspnea, hypoxia, severe abdominal/flank/leg pain, flushing, and urticaria 4
• If infusion reactions occur, temporarily interrupt the infusion and administer intravenous diphenhydramine 4
• For persistent fungal infections despite therapy, investigate for deep tissue focus of infection 3

Special Considerations

• Do not confuse AmBisome (liposomal amphotericin B) with conventional amphotericin B deoxycholate (Fungizone), as this can lead to serious toxicity due to significant dosing differences 5
• AmBisome has significantly less nephrotoxicity than conventional amphotericin B deoxycholate, allowing for higher dosing 6
• For patients with renal impairment, AmBisome is preferred over conventional amphotericin B 4
• Duration of therapy depends on the specific infection being treated, but typically continues until clinical and microbiological resolution 1

Common Pitfalls and Caveats

• Avoid rapid infusion, which can increase the risk of infusion-related reactions 3
• Never substitute different formulations of amphotericin B (liposomal, lipid complex, colloidal dispersion, or conventional) without appropriate dose adjustments 5
• Do not mix or co-infuse with other medications or electrolyte solutions 3
• Store unopened vials at refrigerated temperature (2-8°C) and protect from light 3
• Reconstituted solution can be stored for up to 24 hours at 2-8°C 3