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AIDSinfo Drug Database

AIDSinfo Drug Database

Drugs by class



Primaquine Phosphate  Audio icon

Other Names: primaquine
Drug Class: Opportunistic Infections and Coinfections

Chemical Image:
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primaquine phosphate
primaquine phosphate
Molecular Weight: 455.338

What is primaquine phosphate?

Primaquine phosphate is an antimalarial prescription medicine approved by the U.S. Food and Drug Administration (FDA) for preventing a relapse of vivax malaria—a type of malaria caused by the parasite Plasmodium vivax (P. vivax). Malaria 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.

Primaquine phosphate can also be used “off-label” to treat other opportunistic infections of HIV infection. “Off-label” use refers to use of an FDA-approved medicine in a manner different from that described on the medicine label. Good medical practice and the best interests of a patient sometimes require that a medicine be used “off-label.”

What HIV-related opportunistic infections is primaquine phosphate used for?

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 uses of primaquine phosphate to:

  • Prevent:
    • Relapse of vivax malaria.
    • Relapse of malaria caused by the parasite P. ovale. (This is an “off-label” use.)
  • Treat:
    • Malaria caused by the parasites P. vivax or P. ovale. (This is an off-label use.)
    • Pneumocystis pneumonia (PCP). (This is an “off-label” use.)
The above list may not include all of the HIV-related uses of primaquine phosphate 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 primaquine phosphate?

Before taking primaquine phosphate, tell your health care provider:

  • If you are allergic to primaquine phosphate 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 primaquine phosphate can harm an unborn baby is unknown. Talk to your health care provider about possible risks with taking primaquine phosphate 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. Primaquine phosphate may affect the way other medicines or products work, and other medicines or products may affect how primaquine phosphate works. Ask your health care provider if there are interactions between primaquine phosphate and the other medicines you take.

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

How should I take primaquine phosphate?

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

How should primaquine phosphate be stored?

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

Where can I find more information about primaquine phosphate?

More information about primaquine phosphate is available:

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

Last Reviewed: February 18, 2015

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