Drugs used in the treatment of opioid dependence and treatment of neonatal opiate withdrawal. It is excreted in breast milk in clinically non-significant amount without problems in the short or long term in infants whose mothers were treated. Plasma levels of these infants were undetectable or very low. The dose that gets the infant through the mother's milk, even when taking 70-150 mg a-day, is much lower than that used to treat neonatal abstinence syndrome. This is a reason for not using it as a solely measure of treatment. It should be reinforced that it is observed a non-polydrug behavior and adequacy of maternal care is maintained. Many newborns are either premature or underweight infants, and over 60% develop withdrawal syndrome at about one post-natal month. Breastfeeding with regard to the entire context of addictive behavior is neither easy nor frequently achieved. Much help is needed on supporting addicted mothers by health and social services in the community. Methadone excretion into breast milk is minimal regardless of the dose taken by the mother. No correlation was found between maternal dose and concentration in either breast milk or infant plasma.It has been shown delayed onset of neonatal abstinence syndrome, less need for drug treatment and lower average of hospital stay in breastfed infants.High doses can lead to a slow start (within 2-6 weeks) of withdrawal syndrome when breastfeeding is suddenly stopped. Methadone can cause galactorrhea due to increased prolactin secretion.