Safety issues of maternal drug therapy during breastfeeding.

Two goals when counseling breastfeeding mothers taking medication are protecting the infant from adverse events and permitting necessary maternal therapy. Madadi et al. report a case-control study of neonatal and maternal opioid toxicity after codeine administration. Therapeutic considerations in counseling breastfeeding mothers include susceptibility to drug toxicity of the very young and/or premature infant, significant interindividual variations in drug response, the dose-response relationship with respect to drug toxicity, and the role of pharmacogenetics in both the mother and the infant. These host factors may combine in a particular patient to act synergistically to produce an adverse reaction.