To : Jeanette F. Panchula Re : Olanzaprine (Zyrex) Olanzaprine is a potent neuroleptic drug primarily used for treating schizophrenia. It has a number of typical side effects including extrapyramidal symptoms, occassional elevated liver enzymes, and other typical side effects characteristic of these families of drugs. There is no data that I can find on its transfer into breastmilk but I would assume some of it does transfer simply due to its lipophilicity. Unfortunately, it has a 27 hour half-life and requires glucoronidation for urinary excretion, which as you know is not very functional in newborn livers (it would probably tend to build up over time in the infant). I do not think this would be a suitable drug to use in a breastfeeding mother. Tom Hale