Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral, as succinate:
Krintafel: 150 mg
Tablet, Oral, as succinate [strength expressed as base]:
Arakoda: 100 mg
Pharmacology
Mechanism of Action
Tafenoquine is an 8-aminoquinoline antimalarial drug active against pre-erythrocytic (liver) forms (including hypnozoite [dormant stage]) and erythrocytic (asexual) forms, as well as gametocytes, of Plasmodium species, including P. falciparum and P. vivax. Activity against the pre-erythrocytic liver stage prevents development of the erythrocytic forms of the parasite, which are responsible for relapses in P. vivax malaria. Also causes red blood cell shrinkage in vitro.
Pharmacokinetics/Pharmacodynamics
Absorption
Absorption increased when administered with a high-calorie, high-fat meal
Distribution
Vd: 1,600 to 2,470 L
Time to Peak
12 to 15 hours
Half-Life Elimination
15 to 16.5 days
Protein Binding
>99.5%
Use: Labeled Indications
Malaria, chemoprophylaxis (Arakoda): Prophylaxis of malaria in patients ≥ 18 years of age
Malaria, prevention of relapse of Plasmodium vivax (Krintafel): Radical cure (prevention of relapse) of P. vivax malaria in patients ≥16 years of age who are receiving appropriate antimalarial therapy for acute P. vivax infection
Limitation of use: Not indicated for the treatment of acute P. vivax malaria.
Contraindications
Hypersensitivity to tafenoquine, other 8-aminoquinolines, or any component of the formulation; G6PD deficiency or unknown G6PD status; breastfeeding when the infant is found to be G6PD deficient or if the G6PD status of the infant is unknown; when used for chemoprophylaxis, patients with a history of psychotic disorders or current psychotic symptoms (eg, hallucinations, delusions, grossly disorganized behavior)
Dosage and Administration
Dosing: Adult
Malaria, chemoprophylaxis (Arakoda): Oral:
Note: May be used for up to 6 months of continuous dosing.
Loading regimen (prior to travel): 200 mg once daily for 3 days prior to travel to a malarious area
Maintenance regimen (while in the malarious area): 200 mg once weekly, starting 7 days after the last dose of the loading regimen
Terminal prophylaxis regimen (after leaving malarious area): 200 mg as a single dose, 7 days after the last dose of the maintenance regimen
Missed dose:
Missed 1 loading (daily) dose: Administer a single 200 mg dose (so that a total of 3 daily loading doses have been taken); begin maintenance regimen 1 week after the last loading dose
Missed 2 loading (daily) doses: Administer 200 mg once daily for 2 consecutive days (so that a total of 3 daily loading doses have been taken); begin maintenance regimen 1 week after the last loading dose
Missed 1 maintenance (weekly) dose: Administer a single 200 mg dose on any day up to the time of the next scheduled weekly dose
Missed 2 maintenance (weekly) doses: Administer a single 200 mg dose on any day up to the time of the next scheduled weekly dose
Missed ≥ 3 maintenance (weekly) doses: Administer 200 mg once daily for 2 days up to the time of the next scheduled weekly dose
Missed terminal prophylaxis dose: Administer 200 mg as a single dose as soon as remembered
Malaria, prevention of relapse of P. vivax (Krintafel): Oral: 300 mg as a single dose on the first or second day of the appropriate antimalarial therapy.
Dosing: Geriatric
Refer to adult dosing.
Dosing: Pediatric
Malaria, prevention of relapse: Adolescents ≥16 years: Oral: 300 mg single dose on day 1 or 2 of appropriate antimalarial treatment
Administration
Oral: Administer with food. Swallow tablets whole; do not break, crush, or chew. If vomiting occurs ≤1 hour after dosing for prevention of relapse of P. vivax malaria, repeat dose once (do not attempt re-dosing more than once). When used for chemoprophylaxis, ensure the full course is completed, including loading regimen and the terminal dose.
Dietary Considerations
Take with food.
Storage
Store in original package at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Protect from moisture. Use bottles of 30 tablets within 3 months of opening; do not remove the desiccant.
Drug Interactions
MATE1 Substrates: Tafenoquine may increase the serum concentration of MATE1 Substrates. Management: Avoid use of MATE substrates with tafenoquine, and if the combination cannot be avoided, monitor closely for evidence of toxicity of the MATE substrate and consider a reduced dose of the MATE substrate according to that substrate's labeling. Consider therapy modification
OCT2 Substrates: Tafenoquine may increase the serum concentration of OCT2 Substrates. Management: Avoid use of OCT2 substrates with tafenoquine, and if the combination cannot be avoided, monitor closely for evidence of toxicity of the OCT2 substrate and consider a reduced dose of the OCT2 substrate according to that substrate's labeling. Consider therapy modification
Adverse Reactions
>10%:
Central nervous system: Headache (15%)
Gastrointestinal: Diarrhea (5% to 18%)
Hematologic & oncologic: Methemoglobinemia (13%)
Neuromuscular & skeletal: Back pain (14%)
Ophthalmic: Epithelial keratopathy (21% to 93%)
1% to 10%:
Central nervous system: Dizziness (1% to 5%), sleep disorder (3% to 4%), drowsiness (≤3%), abnormal dreams (2%), insomnia (2%), anxiety (≤1%), depressed mood (≤1%), depression (≤1%)
Gastrointestinal: Nausea (5% to 7%), motion sickness (5%), vomiting (5%)
Hematologic & oncologic: Decreased hemoglobin (2%)
Hepatic: Increased serum alanine aminotransferase (4%)
Hypersensitivity: Hypersensitivity reaction (≤3%)
Ophthalmic: Photophobia (≤3%)
Renal: Increased serum creatinine (≤3%)
<1%, postmarketing and/or case reports: Agitation, amnesia, anemia, ataxia, blurred vision, cholestatic jaundice, corneal disease, decreased estimated GFR (eGFR), decreased visual acuity, hemolytic anemia, hyperacusis, hyperbilirubinemia, hyperesthesia, hypoesthesia, Meniere disease, nocturnal amblyopia, psychoneurosis, retinopathy, suicidal ideation, syncope, thrombocytopenia, tremor, urticaria, visual field defect, visual impairment, vitreous opacity
Warnings/Precautions
Concerns related to adverse effects:
- Hemolytic anemia: Hemolytic anemia may occur in patients with G6PD deficiency; decreased hemoglobin levels were also reported in some G6PD-normal patients. Screen for G6PD deficiency prior to initiation of therapy. Use is contraindicated in patients with G6PD deficiency or unknown G6PD status. Because of the limitations of G6PD tests, be alert to the residual risk of hemolysis and monitor all patients for signs/symptoms of hemolysis (may be delayed in onset/duration due to long half-life of tafenoquine); ensure availability of adequate medical support and follow-up to manage hemolytic risk.
- Hypersensitivity reactions: Serious hypersensitivity reactions (eg, angioedema, urticaria) have been reported; reactions may be delayed in onset and/or duration (due to long half-life of tafenoquine). Discontinue use and institute appropriate treatment if a hypersensitivity reaction occurs; do not readminister in patients who have experienced hypersensitivity reactions to tafenoquine.
- Methemoglobinemia: Asymptomatic elevations in methemoglobin have been reported; carefully monitor patients with nicotinamide adenine dinucleotide (NADH)-dependent methemoglobin reductase deficiency.
- Psychiatric effects: Psychiatric effects (eg, abnormal dreams, anxiety, depression, insomnia) have been reported and may be delayed in onset and/or duration (due to long half-life of tafenoquine). Psychosis was reported in patients with a history of psychiatric disorders following receipt of higher than approved doses. Use with caution in patients with a history of psychiatric illness; use for chemoprophylaxis is contraindicated in patients with a history of psychotic disorders or current psychotic symptoms. Consider discontinuation and prompt evaluation if psychotic symptoms occur; other psychiatric symptoms (eg, anxiety, changes in mood, insomnia, nightmares) should be promptly evaluated if moderate and last more than 3 days or if severe.
Disease-related concerns:
- G6PD deficiency: Screen for G6PD deficiency prior to therapy initiation. Use is contraindicated in patients with G6PD deficiency or unknown G6PD status.
Concurrent drug therapy issues:
- Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
Other warnings/precautions:
- Delayed adverse reactions: Because of the long half-life of tafenoquine (~17 days), adverse reactions (eg, psychiatric effects, hemolytic anemia, methemoglobinemia, hypersensitivity reactions) that may occur could be delayed in onset and/or duration.
Monitoring Parameters
Pregnancy testing (females) and G6PD testing prior to administration; signs/symptoms of hemolysis, hypersensitivity reaction, methemoglobinemia, and psychiatric effects (onset and/or duration of symptoms may be delayed due to long half-life)
Pregnancy
Pregnancy Considerations
Due to the potential for hemolytic anemia to occur in a G6PD-deficient fetus following maternal use of tafenoquine, use during pregnancy is not recommended.
Pregnancy status should be evaluated prior to therapy. When tafenoquine is used in females of reproductive potential, effective contraception should be used during therapy and for 3 months after the last dose.
Patient Education
What is this drug used for?
- It is used to prevent malaria.
- It is used to prevent malaria from coming back.
Frequently reported side effects of this drug
- Nausea
- Vomiting
- Headache
- Back pain
- Diarrhea
- Motion sickness
Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:
- Hemolytic anemia like severe loss of strength and energy, dark urine, or yellow skin.
- Methemoglobinemia like blue or gray color of the lips, nails, or skin; abnormal heartbeat; seizures; severe dizziness or passing out; severe headache; fatigue; loss of strength and energy; or shortness of breath
- Behavioral changes
- Mood changes
- Nightmares
- Trouble sleeping
- Sensing things that seem real but are not
- Confusion
- Severe dizziness
- Passing out
- Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.
Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.
Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.
