May 22 2022


Allopurinol is considered compatible with breastfeeding. However, the available information indicates that an exclusively breastfed baby will probably achieve a blood level of the drug near the therapeutic range, so that, if it is necessary administer this drug to a nursing mother, the child should be monitored, especially the blood count, to rule out a possible toxic effect.

Allopurinol is transformed into the human organism in oxypurinol, which has a similar pharmacological action that its precursor. According to some studies, the rate of absorption of both at usual doses may be 0.14 to 0.20 mg/Kg/day of the first and 7.2-8 mg/kg/day of oxypurinol, which results in a total dose of 10 mg/Kg/day. The plasma concentration of the drug or its metabolite may be comprised in the range of 30-50% of maternal concentration.

No adverse effects have been published about breastfeeding or baby.

Warning of the manufacturer:

Allopurinol and its metabolites appears in human milk 4 hours after taking a dose of 300 mg. There are no data on the effects of these metabolites in the infant.