Common side effects include a reaction with fever, chills, and headaches soon after the medication is given, as well as kidney problems. Allergic symptoms including anaphylaxis may occur. Other serious side effects include low blood potassium and inflammation of the heart. It appears to be relatively safe in pregnancy. There is a lipid formulation that has a lower risk of side effects. It is in the polyene class of medications and works in part by interfering with the cell membrane of the fungus.