What is Benznidazole?

Benznidazole is an antiprotozoal prescription medicine approved by the Food and Drug Administration (FDA) for the treatment of Chagas disease caused by infection with the parasite Trypanosoma cruzi. Benznidazole is FDA-approved for use in children 2 to 12 years of age.

Chagas disease can be opportunistic infections (OI) of HIV. An OI is an infection that occurs more frequently or is more severe in people with weakened immune systems—such as people with HIV—than in people with healthy immune systems. To learn more about OIs, read the HIVinfo What is an Opportunistic Infection? fact sheet.

How is benznidazole used in people with HIV?

The Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV include recommendations on the use of benznidazole to treat Chagas disease and prevent Chagas disease from reactivating.

The recommended uses may not always be consistent with FDA-approved uses of benznidazole. See the Guidelines for complete information on recommended uses of benznidazole in adults and adolescents with HIV. Benznidazole may have other recommended uses not listed above.

What should I tell my health care provider before taking benznidazole?

Before using benznidazole, tell your health care provider:

• If you are allergic to benznidazole, other nitroimidazole agents (such as metronidazole), or any other medicines.
• About any medical conditions you have or have had, including:
  • Cockayne syndrome (a rare genetic disorder)
  • Low blood cell counts
  • Bone marrow suppression
• About anything that could affect your ability to take medicines, such as difficulty swallowing or remembering to take pills.
• If you are pregnant or plan to become pregnant. Benznidazole can harm your unborn baby. Talk to your health care provider about the risks and benefits of taking benznidazole during pregnancy. The Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV may include other recommendations on the use of benznidazole during pregnancy. Please refer to these guidelines for additional information.
• If you are breast/chestfeeding or plan to breast/chestfeed. For people with HIV in the United States, the Guideline recommends speaking with your health care provider to discuss options for feeding your baby. People with suppressed viral load have a less than 1% chance of transmitting HIV to their baby via their own milk.
• About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Benznidazole may affect the way other medicines or products work, and other medicines or products may affect how benznidazole works. Ask your health care provider if there are interactions between benznidazole and the other medicines you take.

Ask your health care provider about possible side effects from benznidazole. Your health care provider will tell you what to do if you have side effects.

How should I take benznidazole?

Take benznidazole according to your health care provider’s instructions. Your health care provider will tell you how much benznidazole to take and when to take it. Before you start benznidazole and each time you get a refill, read any printed information that comes with your medicine.

How should benznidazole be stored?

• Store benznidazole tablets at room temperature, 68°F to 77°F (20°C to 25°C). Protect the tablets from moisture.
• Keep benznidazole in the container that it came in and keep the container tightly closed.
• Do not use benznidazole if the original seal over the container opening is broken or missing.
• Throw away benznidazole that is no longer needed or expired (out of date). Follow FDA Guidelines on how to safely dispose of unused medicine.
• Keep benznidazole and all medicines out of reach of children.

Where can I find more information about benznidazole?

• Recommendations on the HIV-related uses of benznidazole, from the Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV.
• This Patient Version drug summary is based on the following FDA label(s): Tablet. The Patient Counseling Information section of the label and the Instructions For Use include information for people taking benznidazole.
• The American Hospital Formulary Service (AHFS) Patient Medication Information for benznidazole available from MedlinePlus.
• Benznidazole-related research studies, from ClinicalTrials.gov. (The ClinicalTrials.gov search can be modified so that you can get results that better match your interests. To learn more about the ClinicalTrials.gov search features, please see How to Search.)

Last Reviewed: February 19, 2023

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