What is Krintafel (tafenoquine), and how is it used?
- Krintafel is a prescription medicine used to treat malaria caused by a parasite called Plasmodium vivax in patients aged 16 years and older who are also receiving chloroquine to treat acute Plasmodium vivax malaria.
- Malaria is a serious disease of the blood that is spread by infected mosquitos. Krintafel does not work for all types of malaria.
- It is not known if Krintafel is safe and effective in children younger than 16 years.
What are the side effects of Krintafel?
Do not use Krintafel if you:
- have a blood problem called glucose-6-phosphate dehydrogenase (G6PD) deficiency (sometimes known as favism) or you have not been tested for G6PD deficiency. Krintafel can cause a breakdown of red blood cells (hemolysis) in people with G6PD deficiency. Your healthcare provider will test you for G6PD deficiency before you start taking Krintafel.
- are breastfeeding a child known to have G6PD deficiency or breastfeeding a child that has not been tested for G6PD deficiency.
- are allergic to tafenoquine or any of the ingredients in Krintafel or if you have had an allergic reaction to similar medicines containing 8-aminoquinolines.
Krintafel can cause serious side effects, including:
- Breakdown of red blood cells (hemolytic anemia). Contact your healthcare provider if you develop signs of hemolytic anemia, which include darkening of the lips or urine, dizziness, confusion, feeling tired, light-headedness, or shortness of breath.
- Hemolytic anemia in an unborn baby who has G6PD deficiency.
- Females who are able to become pregnant should avoid pregnancy or use effective birth control (contraception) for 3 months after the dose of Krintafel. Talk with your healthcare provider about birth control methods that might be right for you.
- Your healthcare provider will do a pregnancy test before you start taking Krintafel. Tell your healthcare provider right away if you become pregnant or think you might be pregnant during treatment with Krintafel.
- Decrease of oxygen in your blood caused by a certain type of abnormal red blood cell (methemoglobinemia). Get medical help right away if you have darkening of the urine, nail beds, lips, or the inside of your mouth.
- Allergic (hypersensitivity) reactions. Serious allergic reactions can happen after you take Krintafel. Allergic reactions can sometimes happen hours or days after you take a dose of Krintafel. Tell your healthcare provider or get emergency help right away if you have any signs or symptoms of an allergic reaction including:
Other side effects of Krintafel include mental health (psychiatric) symptoms. Krintafel can cause new psychiatric symptoms including anxiety, abnormal dreams, and trouble sleeping (insomnia), or make the symptoms you already have worse. Contact your healthcare provider right away if you have new or worsening psychiatric symptoms.
The most common side effects of Krintafel include: dizziness, nausea, vomiting, headache, and changes in laboratory tests for hemoglobin.
These are not all the possible side effects of Krintafel.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800FDA-1088.
What is the dosage for Krintafel?
- Your healthcare provider will test you for G6PD deficiency before you start taking Krintafel.
- Krintafel is given as 2 tablets that you take together as a single dose.
- You will take Krintafel on the first or second day of your treatment with chloroquine.
- Take Krintafel with food to make sure the right amount of medicine is absorbed into your body.
- Swallow Krintafel tablets whole. Do not break, crush, or chew the tablets.
- If you vomit within 1 hour of taking Krintafel, call your healthcare provider as you may need to take a second dose of Krintafel.
What drugs interact with Krintafel?
Effect Of Krintafel On Organic Cation Transporter-2 (OCT2) And Multidrug And Toxin Extrusion (MATE) Substrates
The effect of coadministration of tafenoquine on the pharmacokinetics of OCT2 and MATE substrates in humans is unknown. However, in vitro
observations suggest the potential for increased concentrations of these
substrates which may increase the risk of toxicity of these drugs.
Avoid coadministration of Krintafel with OCT2 and MATE substrates (e.g., dofetilide, metformin). If coadministration cannot be avoided, monitor for drug-related toxicities and consider dosage reduction if needed based on approved product labeling of the coadministered drug.
Is Krintafel safe to used while pregnant or breastfeeding?
Before taking Krintafel, tell your healthcare provider about all of your medical conditions, including if you:
- are pregnant or plan to become pregnant. Krintafel can harm an unborn baby who has G6PD deficiency.
- are breastfeeding or plan to breastfeed. It is not known if Krintafel passes into breast milk.
- Your healthcare provider should check your child for G6PD deficiency before you start breastfeeding.
- If you know your child has G6PD deficiency, do not breastfeed while taking Krintafel and for 3 months after your last dose of Krintafel.