Nystatin (Nys)

Nystatin is a polyene antifungal medication to which many molds and yeast infections are sensitive, including Candida.  Nystatin is often used as prophylaxis in patients who are at risk for fungal infections, such as AIDS patients with a low CD4+ count and patients receiving chemotherapy. Nystatin is also used as a tool by scientists performing "perforated" patch-clamp electrophysiologic recordings of cells. When loaded in the recording pipette, it allows for measurement of electrical currents without washing out the intracellular contents, because it forms pores in the cell membrane that are permeable to only monovalent ions. Like amphotericin B and natamycin, nystatin binds to ergosterol, a major component of the fungal cell membrane. When present in sufficient concentrations, it forms pores in the membrane that lead to K+ leakage and death of the fungus.