Amphotericin B
A polyene antifungal given by IV infusion for life-threatening fungal infections and visceral leishmaniasis.
Also called AmB (abbreviation).
Drug card
- Class
- Polyene antifungal
- How it works
- Binding ergosterol and forming pores that make the fungal membrane leak
- Used for
- Life-threatening systemic fungal infections
- Cryptococcal meningitis
- Aspergillosis
- Visceral leishmaniasis (liposomal form)
- Known for
- Fever, shaking chills and rigors with infusions
- Kidney damage, sometimes permanent
- Low potassium (hypokalemia)
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does amphotericin B work?
Amphotericin B, made by Streptomyces nodosus, binds ergosterol and forms channels through the fungal membrane, so sodium, potassium and hydrogen ions leak out and the cell dies. It also binds cholesterol in human membranes, causing its toxicity. Besides the conventional deoxycholate form, lipid and liposomal forms cause fewer infusion reactions and less kidney harm.
Like other polyene antifungals: Polyenes bind ergosterol in the fungal cell membrane and form channels through it, so potassium, sodium and other contents leak out and the cell dies. They bind the cholesterol of human cells less strongly, but enough for amphotericin B to harm human tissue, the kidney most. Nystatin is barely absorbed from the gut, so it acts only in the mouth, gut or skin.
Uses
What is amphotericin B used for?
- Life-threatening systemic fungal infections
- Cryptococcal meningitis
- Aspergillosis
- Visceral leishmaniasis (liposomal form)
Side effects
Side effects of amphotericin B
- Fever, shaking chills and rigors with infusionsKnown for
- Kidney damage, sometimes permanentKnown forSerious
- Low potassium (hypokalemia)Known forSerious
- Low magnesium (hypomagnesemia)
- Anemia
- Low blood pressure
- Nausea, vomiting and loss of appetite
- Headache
- Pain and phlebitis at the infusion site
- Arrhythmias and cardiac arrest with overdoseSerious
- Liver injury (rare)Serious
- AnaphylaxisSerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Monitor kidney function, potassium and magnesium often; fluids and salt before doses can lessen kidney damage.
- Aminoglycosides and ciclosporin add to kidney harm; low potassium makes digoxin toxicity more likely.
- Conventional and lipid forms are dosed differently: check the product, since overdose can stop the heart.
- Reserved for serious infections, not for mild thrush in people with normal neutrophil counts.
Good to know: Reserved for dangerous infections. Infusion reactions are worst with the first doses and ease later. Lipid and liposomal forms cause fewer chills and less kidney damage than the conventional form.
Remember it
A way to remember it
Polyenes punch pores in the fungal membrane.
Amphotericin B and nystatin bind ergosterol and line up into pores, so ions leak out and the fungus dies. They also bind some human cholesterol, which is why amphotericin B harms human cells, the kidney most.
Written for biofideX
Its class
Polyene antifungals
Other polyene antifungals with a card:
Easily mixed up with azole antifungals and allylamines.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Amphotericin B for injection: label (DailyMed)
- Amphotericin B liposome for injection: label (DailyMed)
- Amphotericin B (NCI Thesaurus)
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Antifungals and antiparasitics
Amphotericin B is one of 14 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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