Administration Protocol for Lyophilized Amphotericin B
Lyophilized amphotericin B should be reconstituted with sterile water for injection to create a 5 mg/mL concentrate, then further diluted with 5% dextrose solution to a final concentration of 0.1 mg/mL before administration via slow intravenous infusion over 2-6 hours. 1
Reconstitution Process
- Rapidly add 10 mL of sterile water for injection (without bacteriostatic agents) directly into the vial containing the lyophilized cake using a sterile needle (minimum 20-gauge) and syringe 1
- Shake the vial immediately until a clear colloidal solution forms (5 mg/mL concentration) 1
- Further dilute this concentrate 1:50 with 5% dextrose injection to achieve the recommended final concentration of 0.1 mg/mL 1
- Ensure the pH of the dextrose solution is above 4.2 to prevent precipitation; if below 4.2, add buffer solution 1
- Use strict aseptic technique throughout preparation as the product contains no preservatives 1
Administration Guidelines
- Administer via intravenous infusion over 2-6 hours depending on dose 1
- Consider administering a test dose (1 mg in 20 mL of 5% dextrose solution over 20-30 minutes) before full therapeutic dosing 1
- Monitor vital signs every 30 minutes for 2-4 hours during initial administration 1
- Pre-medicate with diphenhydramine or acetaminophen to reduce infusion-related reactions 2
- Administer 1 L of normal saline before and after infusion to reduce nephrotoxicity in patients who can tolerate fluids 2, 3
Dosing Recommendations
- For conventional amphotericin B deoxycholate: 0.5-1.5 mg/kg/day IV 4, 5
- For severe or life-threatening infections: 0.7-1.0 mg/kg/day 4, 5
- For lipid formulations:
Special Administration Situations
- For intravitreal injection: 5-10 μg/0.1 mL sterile water 2
- For intraventricular administration through CNS devices: 0.01-0.5 mg in 2 mL 5% dextrose in water 2
- For bladder irrigation: 50 mg/L sterile water daily for 5 days 2
Important Precautions
- Do not reconstitute with saline solutions as this will cause precipitation 1
- Do not use if there is any evidence of precipitation or foreign matter 1
- If using an in-line filter, ensure the mean pore diameter is not less than 1.0 micron 1
- Store reconstituted solution at 4-8°C if not used immediately 6
- Discard unused solution as it contains no preservatives 1
Monitoring During Therapy
- Monitor renal function, electrolytes, and liver function tests regularly 5
- Watch for infusion-related reactions including fever, chills, nausea, and vomiting 5
- For persistent fungal infections despite therapy, investigate for deep tissue focus of infection 5
Lipid formulations of amphotericin B have similar efficacy but significantly less nephrotoxicity compared to conventional formulations, making them preferable for patients with renal impairment or those requiring higher doses 4, 7.