Paired blood and breast-milk samples were collected from 10 nursing mothers
receiving sertraline. Samples were collected at steady state when the pati
ents had been taking stable doses of 50-150 mg/day over several weeks. Sert
raline concentrations in both fluids were determined using a specific, vali
dated HPLC method. Plasma and milk concentrations showed a wide inter-indiv
idual variability for the same dose. Mean plasma concentrations were linear
ly related to dose, but this was not the case for breast-milk concentration
s. An overall milk to plasma ratio of 1.76 +/- 1.72 was recorded. The avera
ge dose to the infants ranged from 1.1 to 31.1 mu g/kg, which is less than
2 per cent of the maternal dose per day. Further studies are necessary to d
etermine if these doses are detrimental to the development of the infant. C
opyright (C) 2000 John Wiley & Sons, Ltd.