Used for the treatment of myeloproliferative disorders (polycythemia vera, essential thrombocythemia, myeloid leukemia, myeloid splenomegaly), certain cancers and prevention of recurrent painful occlusive crisis in sickle cell anemia from older than 2 years old . It is excreted in breast milk in small amounts, below 10% of relative adult dose or theoretical dose in pediatric patients, so it is not expected the occurrence of side effects on the breastfed infant whose mother is receiving this treatment. Risk may be lowered, especially in infants younger than 3 months, by delaying breastfeeding from 12 to 24 hours after dose.Whenever a long-term treatment is desired monitoring of blood count in the infant should be considered.