Project Details

Neonatal and infant exposures to tafenoquine and primaquine during treatment in lactating women

Rose McGready, MD, PhD

Summary

BACKGROUND: Plasmodium vivax infection malaria follows a chronic, relapsing course, leading to cumulative morbidity and mortality, and in pregnancy increases fetal loss and growth restriction. Primaquine and tafenoquine provide radical cure but both drugs are contraindicated in pregnancy while limited evidence suggests they may be safe in lactation. GAP: This study will help determine the safety of primaquine and tafenoquine postpartum and during lactation, an operationally strategic moment when keeping mothers healthy has a direct impact on offspring, risk of drug-related adverse events to offspring are expected to be low, and women are the most likely to access healthcare services. HYPOTHESIS: Transfer of tafenoquine and primaquine into breast milk of mothers receiving radical cure doses of 8-aminoquinolines throughout the different phases of lactation – colostrum, transitional milk, and mature milk – will result in very low exposure for infants. METHODS: 39 healthy, G6PD normal, lactating women will receive radical curative doses of primaquine or tafenoquine, and drug concentrations in maternal and infant blood, and maternal breast milk will be measured to calculate the estimated drug exposure for the breastfed child. RESULTS: Pilot work suggests no safety risks to infant from tafenoquine in breast milk but this requires confirmation with a complete pharmacokinetic study. IMPACT: Pilot data contributed to improvements in protocol and increased confidence in the safety of the study overall.