What is the recommended dosage of Amphotericin B (Amphotericin B liposomal) for treating fungal infections?

Amphotericin B Liposomal Dosage

For most invasive fungal infections, liposomal amphotericin B should be dosed at 3-5 mg/kg IV daily, with higher doses of 5-10 mg/kg IV daily reserved for CNS infections and severe mucormycosis. 1, 2

Standard Dosing by Infection Type

CNS Candidiasis (Meningitis)

• Dose: 5 mg/kg IV daily 1, 2
• Continue with or without oral flucytosine 25 mg/kg four times daily 1
• Treat until all signs, symptoms, CSF abnormalities, and radiological findings resolve 1

Candida Endophthalmitis/Chorioretinitis

• For fluconazole-resistant isolates: 3-5 mg/kg IV daily 1, 2
• Add intravitreal amphotericin B deoxycholate (5-10 μg/0.1 mL) if macular involvement present 1
• Duration: at least 4-6 weeks, guided by repeated ophthalmological examinations 1

Candidemia and Invasive Candidiasis

• Dose: 3-5 mg/kg IV daily 2
• Reserved for critically ill patients or those with persistent candidemia despite echinocandins 2, 3
• Treat for 14 days after last positive blood culture and resolution of symptoms 4

Mucormycosis

• Without CNS involvement: 5 mg/kg IV daily 2, 3
• With CNS involvement: 10 mg/kg IV daily 2, 3
• Duration: 4-6 weeks for induction/consolidation, then maintenance for 3-6 months 3
• Immediate surgical debridement is mandatory alongside antifungal therapy 3

Histoplasmosis

• Moderately severe to severe disseminated disease: 3 mg/kg IV daily for 1-2 weeks 2
• Follow with oral itraconazole for step-down therapy 2
• Acute pulmonary with respiratory complications: 3 mg/kg IV daily 2

Critical Dosing Distinctions

Liposomal vs. Conventional Amphotericin B

The dosing differs dramatically between formulations, and confusion between these products can be fatal: 1, 5

• Conventional amphotericin B deoxycholate: 0.5-1.0 mg/kg IV daily (maximum 1.5 mg/kg) 1, 4, 5
• Liposomal amphotericin B: 3-5 mg/kg IV daily (up to 10 mg/kg for CNS infections) 1, 2
• Amphotericin B lipid complex (ABLC): 5 mg/kg IV daily 4
• Amphotericin B colloidal dispersion (ABCD): 3-6 mg/kg IV daily 4

These formulations are NOT interchangeable—verify product name and dosage before every administration. 5

Renal Impairment Considerations

No dose adjustment is required for liposomal amphotericin B in chronic kidney disease or dialysis patients. 2

• Liposomal amphotericin B is not renally eliminated and does not accumulate in renal dysfunction 2
• Not dialyzable—no supplemental dosing needed post-hemodialysis 2
• Use indication-specific doses (3-10 mg/kg/day) regardless of baseline creatinine 2
• Common pitfall: Do not reduce the dose based solely on elevated creatinine, as this compromises efficacy without improving safety 2
• Monitor serum creatinine, potassium, and magnesium during therapy 2

Administration Guidelines

Infusion Preparation and Rate

• Concentration: 0.1 mg/mL in 5% dextrose 5
• Infusion time: 2-6 hours depending on dose 4, 5
• Never reconstitute with saline solutions—this causes precipitation 5
• Use sterile water for injection without bacteriostatic agents 5

Toxicity Prevention

• Premedicate with diphenhydramine or acetaminophen to reduce infusion-related reactions 4, 3
• Administer 1 L normal saline before and after infusion in patients who can tolerate fluids to reduce nephrotoxicity 4, 3
• Avoid concomitant nephrotoxic medications when possible 2

Special Populations

Neonates and Pediatric Patients

• Conventional amphotericin B: 1 mg/kg IV daily for disseminated candidiasis 3
• Liposomal formulations use same weight-based dosing as adults 4
• Fluconazole half-life is prolonged in neonates (55-90 hours vs. 30 hours in adults), but once-daily dosing at 5 mg/kg remains appropriate 1

High-Dose Considerations

Higher doses (10 mg/kg/day) do not improve efficacy for most infections but increase nephrotoxicity risk. 6

• A randomized trial in invasive mold infections showed no statistical difference in efficacy between 3 mg/kg/day (50% favorable response) and 10 mg/kg/day (46% favorable response) 6
• The standard 3 mg/kg/day dose was better tolerated 6
• Reserve 10 mg/kg/day exclusively for mucormycosis with CNS involvement 2, 3

Comparative Efficacy and Safety

Liposomal amphotericin B demonstrates equivalent efficacy to conventional amphotericin B with superior tolerability: 6, 7

• Similar success rates for empirical therapy in febrile neutropenia (approximately 50% vs. amphotericin B deoxycholate, 40% vs. ABLC) 6
• Significantly fewer infusion-related reactions and less nephrotoxicity than conventional formulation 6, 7
• Better tolerated than other lipid formulations (ABLC, ABCD) with lower rates of both infusion reactions and nephrotoxicity 6, 7
• Echinocandins (caspofungin, micafungin) show noninferior efficacy with better tolerability profiles 6