How to Administer Liposomal Amphotericin B Injection
Preparation and Reconstitution
Liposomal amphotericin B should be administered intravenously at a concentration of 0.1 mg/mL (1 mg/10 mL) in 5% dextrose solution, infused over 2-3 hours. 1
- Reconstitute the lyophilized powder by rapidly injecting 10 mL of Sterile Water for Injection directly into the vial using a sterile needle (minimum 20 gauge diameter) 2
- Shake the vial immediately until a clear colloidal solution forms 2
- Further dilute the concentrate 1:50 with 5% Dextrose Injection (pH above 4.2) to achieve the final concentration of 0.1 mg/mL 2
- Never use saline solutions or diluents containing bacteriostatic agents (like benzyl alcohol), as these will cause precipitation 2
- Strict aseptic technique is mandatory throughout preparation, as no preservative is present 2
Pre-Medication Protocol
Administer diphenhydramine or acetaminophen before infusion to prevent infusion-related reactions. 1, 3
- Give 1 liter of normal saline intravenously 30 minutes before the amphotericin B infusion in patients who can tolerate fluids 1, 3
- Administer another 1 liter of normal saline after the infusion to reduce nephrotoxicity 1, 3
Dosing Regimens
Standard Infections
For most invasive fungal infections, administer 3-5 mg/kg once daily intravenously. 4, 5, 3
- The standard dose of 3 mg/kg/day has demonstrated 50% response rates and 72% survival at 12 weeks for invasive aspergillosis 6
- Higher doses (10 mg/kg/day) provide no additional benefit and significantly increase nephrotoxicity and hypokalemia 6
CNS Involvement (Mucormycosis or Cryptococcal Meningitis)
For infections involving the central nervous system, increase the dose to 10 mg/kg once daily. 1
- This higher dose is specifically recommended for mucormycosis with CNS involvement 1
- For cryptococcal meningitis, 4-6 mg/kg daily is recommended 3
Pediatric Dosing
- For children with cryptococcal meningitis: 2 mg/kg daily, with doses up to 7.5 mg/kg daily for refractory cases 3
Infusion Protocol
Infuse liposomal amphotericin B over 2-3 hours at the recommended concentration. 1
- Monitor vital signs (temperature, pulse, respiration, blood pressure) every 30 minutes for the first 2-4 hours 2
- An in-line membrane filter may be used, but the mean pore diameter must be at least 1.0 micron to allow passage of the drug dispersion 2
- If infusion-related reactions occur (chest pain, dyspnea, hypoxia, severe abdominal/flank/leg pain, flushing, urticaria), temporarily interrupt the infusion and administer intravenous diphenhydramine 3
Duration of Therapy
Induction/Primary Therapy
Treat for 4-6 weeks during the induction and consolidation phase. 1
Maintenance Therapy
Continue maintenance therapy for 3-6 months until complete resolution of clinical signs, symptoms, and radiological findings. 1
- For candidemia specifically, continue treatment for 14 days after the last positive blood culture and resolution of signs and symptoms 4, 5
Monitoring Requirements
Monitor renal function, electrolytes (especially potassium), and liver function tests regularly throughout therapy. 4, 3
- Liposomal amphotericin B causes significantly less nephrotoxicity (19%) compared to conventional amphotericin B (34%) 7
- Infusion-related reactions (fever, chills, rigors) occur in only 17-18% of patients with liposomal formulation versus 44-54% with conventional amphotericin B 7
- Watch for hypokalemia, which requires monitoring and replacement 6
Critical Pitfalls to Avoid
- Never reconstitute with saline or use bacteriostatic water - this causes immediate precipitation and renders the drug unusable 2
- Do not use if any precipitation or foreign matter is visible in either the concentrate or final infusion solution 2
- Do not use filters smaller than 1.0 micron - they will block passage of the liposomal formulation 2
- Do not skip pre-hydration with normal saline in patients who can tolerate fluids - this significantly reduces nephrotoxicity 1, 3
- For persistent fungal infections despite appropriate therapy, investigate for deep tissue foci of infection that may require surgical debridement 4, 3