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AIDSinfo Drug Database

AIDSinfo Drug Database

Drugs by class



Sulfadiazine  Audio icon

Drug Class: Opportunistic Infections and Coinfections

Chemical Image:
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Molecular Weight: 250.281

What is sulfadiazine?

Sulfadiazine is an antibacterial prescription medicine approved by the U.S. Food and Drug Administration (FDA) to prevent and treat certain types of bacterial infections, including treatment of chancroid (a sexually transmitted infection), Toxoplasma gondii encephalitis (also called toxoplasmosis), urinary tract infections, and others.

Toxoplasma gondii encephalitis is an opportunistic infection. An opportunistic infection is an infection that occurs more frequently or is more severe in people with weakened immune systems—such as those infected with HIV—than in people with healthy immune systems. To learn more about opportunistic infections, read the AIDSinfo What is an Opportunistic Infection? fact sheet.   

The Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents, prepared by the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and the HIV Medicine Association of the Infectious Diseases Society of America (IDSA-HIVMA), includes recommendations on the HIV-related use of sulfadiazine to treat Toxoplasma gondii encephalitis and to prevent Toxoplasma gondii encephalitis from recurring (called secondary prophylaxis or maintenance therapy).

The above list may not include all of the HIV-related uses of sulfadiazine recommended in the Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents. Some recommended uses, such as uses in certain rare circumstances, may have been omitted.

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

Before taking sulfadiazine, tell your health care provider:

  • If you are allergic to sulfadiazine or any other medicines.
  • About any medical conditions you have or have had, for example, diabetes or liver problems.
  • 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. Whether sulfadiazine can harm an unborn baby is unknown. Talk to your health care provider about possible risks with taking sulfadiazine when pregnant.
  • If you are breastfeeding or plan to breastfeed. Do not breastfeed if you are infected with HIV.
  • About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Sulfadiazine may affect the way other medicines or products work, and other medicines or products may affect how sulfadiazine works. Ask your health care provider if there are interactions between sulfadiazine and the other medicines you take.

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

How should I take sulfadiazine?

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

How should sulfadiazine be stored?

  • Store sulfadiazine tablets at room temperature, 68°F to 77°F (20°C to 25°C).
  • Store sulfadiazine tablets in a tight container and protect from light.
  • Do not use sulfadiazine if the original seal over the bottle opening is broken or missing.
  • Throw away sulfadiazine that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine.
  • Keep sulfadiazine and all medicines out of reach of children.

Where can I find more information about sulfadiazine?

More information about sulfadiazine is available:

The above Patient Version drug summary is based on the following FDA label(s): Tablet.

Last Reviewed: September 9, 2016

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