BREAST-FEEDING DURING TREATMENT WITH CYCLOSPORINE

Background. Mothers treated with cyclosporine (CsA) have previously no t been allowed to breast-feed due to the reported accumulation of the drug in breast milk. The purpose of this study was to evaluate the con sequences of allowing breast-feeding. Methods. Seven infants were brea st-fed by mothers who had undergone kidney transplantation alone (n=5) or simultaneous kidney and pancreas transplants (n=2). In addition to CsA, all mothers received prednisolone at 5-7.5 mg/day and six mother s received azathioprine at 50-100 mg. CsA concentration was measured i n the whole blood of mothers and babies and in breast milk. Serum crea tinine was measured in babies 1 week after birth and after 4-12 months of breast-feeding. Results. Blood CsA levels ranged from 55 to 130 ng /ml in mothers (12-hr trough), 50 to 227 ng/ml in breast milk (mean fo r each woman), and was below the detection limit of 30 ng/ml in all in fants. Breast milk concentration ranged from 87 to 440 ng/ml in 16 sam ples obtained at various time points from one mother. Infants' serum c reatinine ranged from 25 to 54 mu mol/L at 1 week after birth and 23-5 2 mu mol/L after breastfeeding. All babies thrived. Conclusions. Breas t-fed infants of mothers treated with CsA received less than 300 mu g per day of CsA and absorbed undetectable amounts. There were no demons trable nephrotoxic effects or other side effects. Thus, women with kid ney transplants could be allowed to breast-feed.