Warnings for Krintafel
Included as part of the PRECAUTIONS section.
Precautions for Krintafel
Hemolytic Anemia
Due to the risk of hemolytic anemia in patients with G6PD deficiency, G6PD testing must be performed before prescribing KRINTAFEL [see DOSAGE AND ADMINISTRATION]. Due to the limitations of G6PD tests, physicians need to be aware of residual risk of hemolysis and adequate medical support and follow-up to manage hemolytic risk should be available. Treatment with KRINTAFEL is contraindicated in patients with G6PD deficiency or unknown G6PD status [see CONTRAINDICATIONS]. Patients were excluded from clinical trials of KRINTAFEL if they had a G6PD enzyme activity level <70% of the site median value for G6PD normal activity [see Clinical Studies]. In clinical trials, declines in hemoglobin levels were reported in some G6PD-normal patients [see ADVERSE REACTIONS]. Monitor patients for clinical signs or symptoms of hemolysis. Advise patients to seek medical attention if signs of hemolysis occur.
G6PD Deficiency In Pregnancy Or Lactation
Potential Harm To The Fetus
The use of KRINTAFEL during pregnancy may cause hemolytic anemia in a G6PD-deficient fetus. Even if a pregnant woman has normal levels of G6PD, the fetus could be G6PD deficient. Advise females of reproductive potential that treatment with KRINTAFEL during pregnancy is not recommended and to avoid pregnancy or use effective contraception for 3 months after the dose of KRINTAFEL [see Use In Specific Populations].
Potential Harm To The Breastfeeding Infant
A G6PD-deficient infant may be at risk for hemolytic anemia from exposure to KRINTAFEL through breast milk. Infant G6PD status should be checked before breastfeeding begins. KRINTAFEL is contraindicated in breastfeeding women when the infant is found to be G6PD deficient or the G6PD status of the infant is unknown [see CONTRAINDICATIONS]. Advise the woman with a G6PD-deficient infant or if the G6PD status of the infant is unknown not to breastfeed for 3 months after the dose of KRINTAFEL [see Use In Specific Populations].
Methemoglobinemia
Asymptomatic elevations in methemoglobin have been observed in the clinical trials of KRINTAFEL [see ADVERSE REACTIONS]. Institute appropriate therapy if signs or symptoms of methemoglobinemia occur. Carefully monitor individuals with nicotinamide adenine dinucleotide (NADH)-dependent methemoglobin reductase deficiency. Advise patients to seek medical attention if signs of methemoglobinemia occur.
Psychiatric Effects
Psychiatric adverse reactions including anxiety (<1%), abnormal dreams (<1%), and insomnia (3%) have been reported in clinical trials of KRINTAFEL [see ADVERSE REACTIONS]. Two cases of depression and 2 cases of psychosis have occurred primarily in patients with a history of psychiatric disorders following receipt of single doses of tafenoquine that were higher than the approved 300-mg dose (350 mg to 600 mg). Safety and effectiveness of KRINTAFEL have not been established at doses or regimens other than the approved regimen; use of KRINTAFEL at doses or regimens other than a 300-mg single dose is not approved by FDA.
The benefit of treatment with KRINTAFEL must be weighed against the potential risk for psychiatric adverse reactions in patients with a history of psychiatric illness. Due to the long half-life of KRINTAFEL (approximately 15 days), signs or symptoms of psychiatric adverse reactions that may occur could be delayed in onset and/or duration [see CLINICAL PHARMACOLOGY].
Hypersensitivity Reactions
Serious hypersensitivity reactions (e.g., angioedema, urticaria) have been observed with administration of KRINTAFEL [see ADVERSE REACTIONS]. Institute appropriate therapy if hypersensitivity reactions occur. Do not re-administer KRINTAFEL. KRINTAFEL is contraindicated in patients who develop hypersensitivity to tafenoquine or any component of KRINTAFEL or other 8-aminoquinolines [see CONTRAINDICATIONS].
Due to the long half-life of KRINTAFEL (approximately 15 days), signs or symptoms of hypersensitivity adverse reactions that may occur could be delayed in onset and/or duration [see CLINICAL PHARMACOLOGY]. Advise patients to seek medical attention if signs of hypersensitivity occur.
Risk Of P. vivax Malaria Recurrence
Lack of efficacy in reducing P. vivax malaria recurrence in patients treated with KRINTAFEL combined with an artemisinin-containing antimalarial was seen in a clinical trial (NCT02802501). In this double-blind, randomized, placebo-controlled trial in which all patients with P. vivax malaria were treated with dihydroartemisinin/piperaquine (not approved artemisinin-containing antimalarial) and were coadministered KRINTAFEL, primaquine, or placebo, lack of efficacy (recurrence rates at 6 months following treatment) was seen in patients treated with KRINTAFEL.
Concomitant administration of KRINTAFEL with antimalarials other than chloroquine is not recommended.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
G6PD Testing And Hemolytic Anemia
Inform patients of the need for testing for G6PD deficiency before starting KRINTAFEL. Advise patients of the symptoms of hemolytic anemia and instruct them to seek medical advice promptly if such symptoms occur. Patients should contact their healthcare provider if they develop dark lips or urine as these may be signs of hemolysis or methemoglobinemia [see WARNINGS AND PRECAUTIONS].
Important Administration Instructions
Advise patients to take KRINTAFEL with food to increase absorption [see DOSAGE AND ADMINISTRATION].
Advise patients to swallow the tablet whole and not to break, crush, or chew it.
Potential Harm To The Fetus
Advise females of reproductive potential of the potential risk of KRINTAFEL to a fetus and to inform their healthcare provider of a known or suspected pregnancy [see WARNINGS AND PRECAUTIONS, Use In Specific Populations].
Advise females of reproductive potential to avoid pregnancy or use effective contraception for 3 months after the dose of KRINTAFEL [see Use In Specific Populations].
Lactation
Advise women with a G6PD-deficient infant, or if they do not know the G6PD status of their infant, not to breastfeed for 3 months after the dose of KRINTAFEL [see CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS, Use In Specific Populations].
Methemoglobinemia
Inform patients that methemoglobinemia has occurred with KRINTAFEL. Advise patients of the symptoms of methemoglobinemia and instruct them to seek medical advice promptly if such symptoms occur [see WARNINGS AND PRECAUTIONS].
Psychiatric Symptoms
Advise patients with a history of psychiatric illness regarding the potential for new or worsening psychiatric symptoms with KRINTAFEL and instruct them to seek medical advice promptly if such symptoms occur [see WARNINGS AND PRECAUTIONS].
Hypersensitivity Reactions
Inform patients that hypersensitivity reactions have occurred with KRINTAFEL. Advise patients of the symptoms of hypersensitivity reactions and instruct them to seek medical advice promptly if such symptoms occur [see WARNINGS AND PRECAUTIONS].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenesis
Two-year oral carcinogenicity studies were conducted in rats and mice. Renal cell adenomas and carcinomas were increased in male rats at doses of 1 mg/kg/day and above (3 times the clinical exposure based on AUC comparisons). Tafenoquine was not carcinogenic in mice. Given the single-dose administration of KRINTAFEL, these findings may not represent a carcinogenicity risk to humans.
Mutagenesis
Tafenoquine did not cause mutations or chromosomal damage in 2 definitive in vitro tests (bacterial mutation assay and mouse lymphoma L5178Y cell assay) or in an in vivo oral rat micronucleus test.
Impairment Of Fertility
In a rat fertility study, tafenoquine was given orally at 1.5, 5, and 15 mg/kg/day (up to about 0.5 times the human dose based on body surface area comparisons) to males for at least 67 days, including 29 days prior to mating, and to females from 15 days prior to mating through early pregnancy. Tafenoquine resulted in reduced number of viable fetuses, implantation sites, and corpora lutea at 15 mg/kg in the presence of maternal toxicity (mortality, piloerection, rough coat, and reduced body weight).
Use In Specific Populations
Pregnancy
Risk Summary
The use of KRINTAFEL during pregnancy may cause hemolytic anemia in a fetus who is G6PD deficient. Treatment with KRINTAFEL during pregnancy is not recommended [see WARNINGS AND PRECAUTIONS]. Available data with use of KRINTAFEL in pregnant women are insufficient to establish a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. In animal studies, there were increased abortions, with and without maternal toxicity, when KRINTAFEL was given orally to pregnant rabbits at and above doses equivalent to about 0.4 times the clinical exposure based on body surface area comparisons. No fetotoxicity was observed at doses equivalent to the clinical exposure (based on body surface area comparisons) in a similar study in rats.
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
Clinical Considerations
Disease-Associated Maternal And/Or Embryo/Fetal Risk
Malaria during pregnancy increases the risk for adverse pregnancy outcomes, including maternal anemia, prematurity, spontaneous abortion, and stillbirth.
Data
Animal Data
Tafenoquine resulted in dose-related abortions when given orally to pregnant rabbits during organogenesis (Gestation Days 6 to 18) at doses of 7 mg/kg (about 0.4 times the clinical exposure based on body surface area comparisons) and above. Doses higher than 7 mg/kg were also associated with maternal toxicity (mortality and reduced body weight gain). In a similar study in rats, doses of 3, 10, or 30 mg/kg/day resulted in maternal toxicity (enlarged spleen, reduced body weight, and reduced food intake) but no fetotoxicity at the high dose (equivalent to the clinical exposure based on body surface area comparisons).
There was no evidence of malformations in either species. In a pre- and postnatal development study in rats, tafenoquine administered throughout pregnancy and lactation produced maternal toxicity and a reversible decrease in offspring body weight gain and decrease in motor activity at 18 mg/kg/day, which is equivalent to about 0.6 times the clinical dose based on body surface area comparisons.
Lactation
Risk Summary
A breastfed infant with G6PD deficiency is at risk for hemolytic anemia from exposure to KRINTAFEL. Infant G6PD status should be checked before breastfeeding begins. KRINTAFEL is contraindicated in breastfeeding women when the infant is found to be G6PD deficient or the G6PD status of the infant is unknown [see CONTRAINDICATIONS, Clinical Considerations].
There is no information regarding the presence of KRINTAFEL in human milk, the effects of the drug on the breastfed infant, or the effects of the drug on milk production. In a breastfed infant with normal G6PD, the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for KRINTAFEL and any potential effects on the breastfed infant from KRINTAFEL or from the underlying maternal condition.
Clinical Considerations
Check the infant’s G6PD status before maternal breastfeeding commences. If an infant is G6PD deficient, exposure to KRINTAFEL during breastfeeding may result in hemolytic anemia in the infant; therefore, advise the woman with an infant who has G6PD deficiency or whose G6PD status is unknown not to breastfeed for 3 months after the dose of KRINTAFEL.
Females And Males Of Reproductive Potential
Pregnancy Testing
Verify the pregnancy status in females of reproductive potential prior to initiating treatment with KRINTAFEL [see WARNINGS AND PRECAUTIONS, Use In Specific Populations].
Contraception
KRINTAFEL may cause hemolytic anemia in a G6PD-deficient fetus [see WARNINGS AND PRECAUTIONS, Use In Specific Populations]. Advise females of reproductive potential that treatment with KRINTAFEL during pregnancy is not recommended and to avoid pregnancy or use effective contraception for 3 months after the dose of KRINTAFEL.
Pediatric Use
The safety and effectiveness of KRINTAFEL have been established in pediatric patients aged 16 years and older. Use of KRINTAFEL in these pediatric patients is supported by evidence from adequate and wellcontrolled studies of KRINTAFEL [see Clinical Studies].
Safety and effectiveness of KRINTAFEL in pediatric patients younger than 16 years have not been established.
Geriatric Use
Clinical trials of KRINTAFEL did not include sufficient numbers of patients aged 65 years and older to determine whether they respond differently from younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients [see CLINICAL PHARMACOLOGY].
Renal Impairment
The pharmacokinetics of KRINTAFEL have not been studied in patients with renal impairment. If KRINTAFEL is administered to such patients, monitoring for adverse reactions associated with KRINTAFEL is needed [see WARNINGS AND PRECAUTIONS, ADVERSE REACTIONS].
Hepatic Impairment
The pharmacokinetics of KRINTAFEL have not been studied in patients with hepatic impairment. If KRINTAFEL is administered to such patients, monitoring for adverse reactions associated with KRINTAFEL is needed [see WARNINGS AND PRECAUTIONS, ADVERSE REACTIONS].