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Overview: Primaquine is used to prevent relapses of malaria. It works by killing parasites that cause malaria. Common side effects of primaquine include nausea and vomiting, stomach cramps, and dizziness. Contact your health care provider right away if you notice that your urine is dark in color, since this could be caused by a serious side effect called hemolytic anemia.

Uses

What is primaquine used for?

Primaquine is commonly used to prevent relapses of malaria (an infection from parasites that can lead to death, often from a mosquito bite).

Primaquine may also be used for other conditions as determined by your health care provider.

How does primaquine work (mechanism of action)?

Primaquine works by killing parasites that cause malaria.

How is primaquine supplied (dosage forms)?

Brands and other names

  • Primaquine

Dosage forms and strengths

  • 26.3 mg oral tablets

How should I store primaquine?

Primaquine should be stored at room temperature, between 68 F and 77 F (20 C and 25 C). It can be exposed to temperatures between 59 F and 86 F (15 C and 30 C) for shorter periods of time, such as when transporting it. Store in a cool, dry place. Protect from light.

Side Effects

What are the most common side effects of primaquine?

The most common side effects of primaquine are listed below. Tell your health care provider if you have any of these side effects that bother you.

  • Nausea and vomiting
  • Stomach cramps
  • Rash
  • Itching
  • Dizziness

There may be other side effects of primaquine that are not listed here. Contact your health care provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of primaquine?

While less common, the most serious side effects of primaquine are described below, along with what to do if they happen.

Severe Allergic Reactions. Primaquine may cause allergic reactions, which can be serious. Stop taking primaquine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Hemolytic Anemia. Primaquine may cause your red blood cells to be destroyed, which is called hemolytic anemia. Having a condition called G6PD deficiency increases your risk. Your health care provider may run tests and stop primaquine if you have hemolytic anemia. Tell your health care provider right away if you notice that your urine is dark in color, since this could be a sign of hemolytic anemia.

Warnings & Precautions

Who should not use primaquine?

Allergies to Ingredients. People who are allergic to any of the following should not take primaquine.

  • Primaquine
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific primaquine products they stock.

G6PD Deficiency. Do not take primaquine if you have severe G6PD deficiency. Your health care provider may test you for G6PD deficiency before starting primaquine.

Low Granulocytes. Primaquine should not be taken by people who have conditions that can cause low levels of blood cells called granulocytes. These conditions include severe cases of lupus erythematosus or rheumatoid arthritis.

Pregnancy. Do not take primaquine if you are pregnant. If you become pregnant, contact your health care provider right away. See the Pregnancy section for more details.

Drug Interactions. Primaquine should not be taken while you are using certain other medicines. Before taking primaquine, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

What should I know about primaquine before using it?

Do not take primaquine unless it has been prescribed to you by a health care provider. Take it as prescribed.

Do not share primaquine with other people, even if they have the same condition as you. It may harm them.

Keep primaquine out of the reach of children.

What should I tell my health care provider before using primaquine?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if primaquine is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

  • A personal or family history of G6PD deficiency
  • A personal or family history of hemolytic anemia
  • A personal or family history of nicotinamide adenine dinucleotide (NADH) methemoglobin reductase deficiency
  • Heart problems, including irregular heart rate or rhythm
  • Low blood levels of magnesium or potassium

Pregnancy. Primaquine may cause harm to a fetus. Tell your health care provider if you are pregnant or plan to become pregnant. You should have a negative pregnancy test before starting primaquine. If you can become pregnant, use effective birth control while you are taking primaquine and until you start your next menstrual period following your last dose. Talk to your health care provider about your birth control options.

If your sexual partner can become pregnant, use a condom while you are taking primaquine and for three months after taking your last dose.

Breastfeeding. It is not known if primaquine passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should stop breastfeeding or stop primaquine.

Interactions

Does primaquine interact with foods or drinks?

There are no known interactions between primaquine and foods or drinks.

It is unknown if drinking alcohol will affect primaquine, but heavy drinking can slow your immune response and make it harder for your body to fight infection. 

Does primaquine interact with other medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. 

In particular, make sure that you discuss if you are using any of the following before taking primaquine.

  • A medicine for irregular heart rate or rhythm
  • Any medicine for cancer
  • Any medicine that suppresses the immune system

This may not be a complete list of medicines that can interact with primaquine. Always check with your health care provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much primaquine?

If you or someone else has used too much primaquine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of primaquine?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.

It is important to complete your prescribed course of primaquine, even if your symptoms get better or go away.