Is primaquine (an antimalarial medication) safe to use during breastfeeding?

Primaquine Safety During Breastfeeding

Very small amounts of primaquine are secreted in breast milk, and the amount transferred is not thought to be harmful to nursing infants, making primaquine generally acceptable for use in breastfeeding women. 1

Safety Profile in Breastfeeding

• Primaquine is secreted in breast milk in very low concentrations, with estimated infant exposure being approximately 0.6% of a therapeutic maternal dose 2
• In clinical studies of breastfeeding women taking primaquine (0.5 mg/kg/day for 14 days), primaquine was below measurement thresholds in almost all infant plasma samples 2
• No evidence of drug-related hemolysis was observed in breastfed infants whose mothers were taking primaquine 2
• The quantity of primaquine transferred in breast milk is insufficient to provide adequate protection against malaria for the infant, so infants requiring chemoprophylaxis should receive their own appropriate dosages 1

Important Considerations Before Use

• G6PD status testing is essential before administering primaquine to the breastfeeding mother due to risk of hemolysis in G6PD-deficient individuals 3
• Primaquine should not be prescribed for breastfeeding women with severe G6PD deficiency 3
• For mothers with mild to moderate G6PD deficiency, a risk-benefit assessment must be conducted before prescribing primaquine 3
• Baseline hematocrit and hemoglobin should be checked before treatment, with close hematological monitoring (e.g., at day 3 and 8) 3

Monitoring Recommendations

• Monitor for signs of hemolytic anemia in both mother and infant (darkening of urine, marked fall of hemoglobin or erythrocyte count) 3
• Discontinue primaquine promptly if signs of hemolysis occur 3
• Adequate medical support to manage potential hemolytic risk should be available 3

Special Populations and Contraindications

• Primaquine is contraindicated during pregnancy due to risk of hemolysis in a potentially G6PD-deficient fetus 3
• The World Health Organization (WHO) has historically listed breastfeeding as a contraindication for primaquine use 4, but recent research supports its safety in this population 2
• Areas with high prevalence of G6PD deficiency (Africa, Southern Europe, Mediterranean region, Middle East, South-East Asia, and Oceania) require particular caution when considering primaquine use 3

Clinical Decision Algorithm

1. Determine if primaquine is clinically indicated (P. vivax/P. ovale radical cure or P. falciparum gametocytocidal effect) 4, 5
2. Test mother for G6PD deficiency before prescribing 3
3. If mother is G6PD normal, primaquine can be administered at appropriate dosage 3, 2
4. Monitor both mother and infant for signs of hemolysis during treatment 3
5. Ensure infant requiring malaria prophylaxis receives appropriate medication directly, as breast milk transfer is insufficient for protection 1

Recent research strongly suggests that primaquine should not be withheld from mothers breastfeeding infants or young children when clinically indicated, though more information is needed for neonates 2.