A strong antifungal given by drip for serious fungal infections
Amphotericin B
A strong antifungal medicine given by drip in hospital to treat serious fungal infections in the body.
What is Amphotericin B?
Amphotericin B is a powerful antifungal given into a vein in hospital to treat serious, deep-seated fungal infections, including in people whose immune system is weakened. It works by damaging the fungal cell's outer covering so the fungus is killed. Its most important problems are toxicity to the kidneys and loss of body salts such as potassium and magnesium, along with infusion reactions like fever and shivering (rigors). Newer liposomal forms, where the medicine is wrapped in tiny fat bubbles, are generally less toxic to the kidneys.
Education and reference only. This is a plain-language guide to Amphotericin B — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Amphotericin B is a strong antifungal medicine used in hospital for serious fungal infections that affect deep parts of the body, such as the blood, lungs or brain, often in people who are very unwell or have weakened immunity. It is given by infusion into a vein. It comes in an older conventional form and in newer liposomal or lipid forms, where the drug is packaged inside tiny fat particles; these are usually kinder to the kidneys and are often preferred. It is a specialist treatment used under close supervision.
How it works
Amphotericin B binds to a substance called ergosterol in the fungal cell's outer membrane, punching tiny holes in it so the cell leaks its contents and dies. Because ergosterol is specific to fungi, the medicine targets fungal cells, but it can also affect human cells to some degree, which is part of why it can harm the kidneys. The liposomal and lipid forms deliver the drug in a way that tends to spare the kidneys while still reaching the infection, which is why they are often chosen for people at higher risk.
Company & origin
Originated / developed by: Specialist manufacturers.
A long-established antifungal used in UK hospitals for serious, deep-seated fungal infections, now often given in a liposomal form that is gentler on the kidneys.
Practical use
How to take Amphotericin B
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by infusion into a vein in hospital by a specialist team, not taken at home.
- Expect blood tests to check your kidneys and salts such as potassium and magnesium before and during treatment.
- Tell the team if you feel feverish, shivery or unwell during the infusion, as the rate can be adjusted or medicines given to help.
- Drink fluids as advised, or accept fluids given into a vein, to help protect your kidneys.
- Make sure the team knows the exact form being used, as conventional and liposomal forms are not interchangeable.
Weighing it up
Advantages & disadvantages of Amphotericin B
Advantages
- Treats serious, deep-seated fungal infections, including in people with weakened immunity.
- Works against a broad range of fungi, including ones that other antifungals may not cover.
- Liposomal and lipid forms are generally less toxic to the kidneys than the older conventional form.
Disadvantages
- Can damage the kidneys and cause loss of body salts such as potassium and magnesium.
- Commonly causes infusion reactions such as fever, chills and shivering.
- Must be given by infusion in hospital with close monitoring.
Practical use
Good to know
The main things to know about amphotericin B are its effects on the kidneys, body salts and the infusion itself. It can reduce kidney function, so kidney blood tests are monitored, and it commonly causes the body to lose potassium and magnesium, which may need to be replaced. During the infusion, fever, chills and shivering (rigors) are common, and the team may give other medicines beforehand or slow the drip to reduce these reactions. Staying well hydrated, often with fluids given into a vein, helps protect the kidneys. The liposomal forms are generally less toxic to the kidneys than the older conventional form, which is one reason they are often preferred, but they are still strong medicines used only when needed. It is always given and monitored by a specialist hospital team.
Who should not take it / use with caution
- People who have had a serious allergic reaction to amphotericin B should not receive it.
- It is used with great caution, and with extra monitoring, in people with existing kidney problems.
- The form and approach are chosen carefully in pregnancy and in people on other medicines that affect the kidneys, under specialist guidance.
Monitoring
- Regular kidney function blood tests before and during treatment.
- Checking and replacing body salts such as potassium and magnesium.
- Watching for infusion reactions and monitoring blood counts and liver tests as needed.
Side effects
- Reduced kidney function, monitored with regular blood tests.
- Loss of potassium and magnesium, which may need replacing.
- Infusion reactions such as fever, chills, shivering, nausea and headache.
Key interactions
- Other medicines that can harm the kidneys may add to the risk of kidney damage.
- Because it lowers potassium, it can increase the effects of medicines such as digoxin and the risk from some heart-rhythm drugs.
- Steroids and certain diuretics can worsen salt loss, so they are reviewed by the team.
Available as: A powder or suspension made up into a solution for infusion into a vein, including liposomal and lipid forms.
Answers
Amphotericin B: frequently asked questions
What is amphotericin B used for?
It is a strong antifungal given by drip in hospital to treat serious, deep-seated fungal infections, often in people who are very unwell or have weakened immunity.
Why does it affect the kidneys?
It can be toxic to the kidneys and cause loss of body salts, so kidney blood tests and salt levels are monitored and fluids are given to help protect them.
What are the liposomal forms?
Liposomal forms wrap the medicine in tiny fat bubbles, which generally makes them less toxic to the kidneys, so they are often preferred for people at higher risk.
Why might I shiver during the infusion?
Fever, chills and shivering are common infusion reactions; the team may give medicines beforehand or slow the drip to reduce them.
Are the different forms the same?
No. The conventional and liposomal forms are not interchangeable, so it is important the team knows exactly which form is being used.
The wider class
About Antifungal (polyene, intravenous)
Amphotericin B belongs to the antifungal (polyene, intravenous) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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