The incidence of psychiatric illness is higher in this period than at any other time in a women's life. Therefore, the question of whether women receiving psychotropic drugs should continue breast feeding is an important one. Drug excretion in breast milk depends mostly on passive diffusion of the unionized unbound drug. Passive diffusion is affected mainly by the drug disposition in lactating mothers, by the physicochemical properties of the molecule and by the protein and lipid contents of breast milk. Indeed, breast milk can be considered as a compartment with bidirectional transfer rather than a reservoir into which drug accumulates.
Benzodiazepines are the most prescribed psychotropic drugs.
Generally there does not seem to be any contraindication to breast feeding after a single dose, provided the dose administered is relatively low. If higher doses are to be used or long term administration is required, then breast feeding should probably be discontinued, particularly with drugs with a long elimination half-life. For glutethimide, breast feeding would appear to be safe for the infant when a single dose is taken occasionally. Zopiclone may also be prescribed on a short term basis to breast feeding mothers. Due to limited available data or to the large amount transferred to milk, administration of phenothiazines and nonphenothiazine tricyclic, butyrophenone, and benzamide antipsychotics to breast feeding mothers cannot be recommended.