Amphotericin B is an anti-fungal medication, often used intravenously for systemic fungal infections. It was originally derived from a bacteria, Streptomyces nodosus in 1955. Although it has few side effects when taken as a pill, it is far more dangerous when injected. It works by binding to the cell membrane of a fungus and interfering with its transfer of potassium, sodium, hydrogen and chlorine, leading to the eventual death of the fungus. However, it can also have the same effect on the membranes of the cells of humans and other mammals. It can also be used to treat parasites and is the drug of last resort against resistant leishmaniasis infections.
Amphotericin B should be avoided in the absence of a definitive diagnosis as it has severe side effects including nausea, fever, low blood pressure, anorexia, vomiting, headache, shortness of breath, rapid breathing, drowsiness and weakness. At therapeutic intravenous doses, it can cause organ damage, kidney failure, electrolyte imbalances, liver damage, arrhythmia and even heart failure. It also has adverse reactions with a wide class of drugs including diuretics and steroids.