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Rezzayo
Generic name: rezafungin
What is Rezzayo?
Rezzayo is a prescription medicine used to treat serious Candida fungal infections called candidemia and invasive candidiasis.
Rezzayo contains rezafungin, which belongs to the class of drugs called echinocandin antifungals.
Rezafungin works as an antifungal by inhibiting the formation of (1-3)-β-d-glucan (BDG), which an essential component of the cell wall of many fungi, including Candida.
Rezzayo is used to treat candidemia and invasive candidiasis in adults and children 12 years of age and older who have limited or no alternative treatment options.
The FDA approval of this indication was based on limited clinical safety and efficacy data.
Invasive candidiasis is a serious infection caused by a yeast (a type of fungus) called Candida that can affect the blood, heart, brain, eyes, bones, or other parts of the body.
Candidemia is the most common form of invasive candidiasis, which is a Candida infection of the bloodstream.
Rezzayo has not been studied in patients with endocarditis, osteomyelitis, and meningitis caused by Candida.
How will I receive Rezzayo?
Your healthcare provider will give you Rezzayo into your vein through an intravenous (IV) line over 1 hour.
Rezzayo is usually given once-weekly. The first dose is a loading dose of 400 mg and the following weekly doses are 200 mg.
Your healthcare provider will decide how many treatments you will need.
Your healthcare provider may do blood tests to check you for side effects.
If you miss any appointments, call your healthcare provider as soon as possible to reschedule your appointment.
Important information
Rezzayo may cause serious hypersensitivity reactions, including anaphylaxis. You should not use this medicine if you have a known hypersensitivity to rezafungin or other echinocandins.
Rezzayo may cause infusion-related reactions, including flushing, sensation of warmth, urticaria, nausea, or chest tightness. If these reactions occur, your healthcare provider will slow or pause the infusion.
Rezzayo may cause photosensitivity reactions. You should use protection from sun exposure and other sources of UV radiation during treatment.
Rezzayo may cause abnormalities in liver tests. Your healthcare provider will monitor you if you develop abnormal liver tests and evaluate the risk versus benefit of continuing treatment.
Before you receive Rezzayo
Before you start treatment, tell your healthcare provider about all of your medical conditions, including if you:
- have a known hypersensitivity to rezafungin or other echinocandins.
Pregnancy
Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known if Rezzayo can harm your baby.
Breastfeeding
Tell your healthcare provider if you are breastfeeding or plan to breastfeed. It may not be safe to breastfeed while using Rezzayo. Talk to your healthcare provider about the best way to feed your baby during treatment.
Rezzayo side effects
Rezzayo may cause serious side effects including:
- hypersensitivity reactions, including anaphylaxis. Get emergency help if you have signs of an allergic reaction (hives, difficulty breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).
- infusion-related reactions. Tell your healthcare provider at once if you have symptoms of an infusion-related reaction (flushing, sensation of warmth, urticaria, nausea, or chest tightness). The infusion should be slowed or paused if these reactions occur.
- photosensitivity reactions. Tell your healthcare provider if you develop a skin rash. You should use protection from sun exposure and other sources of UV radiation during treatment.
- abnormalities in liver tests. Your healthcare provider will monitor you if you develop abnormal liver tests and will weigh up the risks versus benefits of continuing treatment.
Common side effects include:
- hypokalemia (low blood potassium levels);
- pyrexia (fever);
- diarrhea;
- anemia (low levels of red blood cells);
- nausea;
- vomiting;
- hypomagnesemia (low levels of magnesium in the blood);
- abdominal pain;
- constipation; and
- hypophosphatemia (low levels of phosphate in the blood).
Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. If you would like more information, talk with your healthcare provider. You can ask your healthcare provider for information that is written for health professionals.
Dosing information
Usual Adult and Pediatric Dose for Candidemia and Invasive Candidiasis:
400 mg loading dose, followed by a 200 mg dose once weekly thereafter.
Comments: - Administer by intravenous (IV) infusion. Safety has not been established beyond 4 weekly doses.
Use: - treatment of patients 12 years of age or older who have limited or no alternative options for the treatment of candidemia and invasive candidiasis. Approval of this indication is based on limited clinical safety and efficacy data.
What other drugs will affect Rezzayo?
Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
What are the ingredients in Rezzayo?
Active ingredient: rezafungin acetate
Inactive ingredients: histidine, mannitol, polysorbate 80, and hydrochloric acid and/or sodium hydroxide for pH adjustment.
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Content is provided for education and is not medical advice. See our medical disclaimer. Source page medically reviewed by Judith Stewart, BPharm on September 11, 2026.