ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Polyene Antifungal

Amphotericin B

Brand names: AmBisome (liposomal), Fungizone (conventional)

Adult dose

Dose: Liposomal (AmBisome): 3–5 mg/kg once daily. Conventional (Fungizone): 0.5–1.5 mg/kg/day (test dose required). Dose depends on infection type and tolerance
Route: Intravenous infusion
Frequency: Once daily

Clinical pearls

  • Broad-spectrum antifungal: active against Candida, Aspergillus, Cryptococcus, Histoplasma, Mucor
  • Liposomal formulation (AmBisome) preferred over conventional — equivalent efficacy with less nephrotoxicity
  • Test dose required with conventional amphotericin B (1 mg IV over 20–30 min with resuscitation facilities)
  • Pre-hydrate with 1L NaCl 0.9% before each conventional dose to reduce nephrotoxicity
  • NICE TA350 (AmBisome for invasive candidiasis in adults): recommended
  • IDSA and ESCMID guidelines recommend liposomal for cryptococcal meningitis induction (with flucytosine)

Contraindications

  • Severe hypersensitivity to amphotericin B
  • Severe renal impairment (requires dose modification and close monitoring)

Side effects

  • Infusion-related reactions (fever, rigors, nausea — worse with conventional; less with liposomal)
  • Nephrotoxicity (dose-limiting with conventional; less with liposomal)
  • Hypokalaemia, hypomagnesaemia (electrolyte wasting)
  • Anaemia (normochromic normocytic)
  • Hepatotoxicity (rare)
  • Phlebitis (conventional via peripheral vein)

Interactions

  • Nephrotoxic drugs (ciclosporin, tacrolimus, aminoglycosides) — additive nephrotoxicity
  • Loop diuretics — additive electrolyte depletion
  • Digoxin — hypokalaemia increases digoxin toxicity
  • Flucytosine — synergistic antifungal combination (for cryptococcal meningitis)
  • Azole antifungals — pharmacodynamic antagonism (avoid concurrent use)

Monitoring

  • Renal function (eGFR, creatinine) before each dose
  • Serum potassium and magnesium daily (replace aggressively)
  • FBC (anaemia)
  • LFTs weekly
  • Infusion reactions (premedicate with paracetamol, chlorphenamine if needed)

Reference: BNF; IDSA Invasive Candidiasis Guidelines (2016); ESCMID Cryptococcal Meningitis Guidelines (2018); NICE TA350 (AmBisome); BSAC antifungal guidelines; https://bnf.nice.org.uk/drugs/amphotericin/. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Drugs
Pathways