There is no way to be sure about a "highest safest dosage".  It would
be nice if drugs behaved nicely and that two times a maternal dose
results in two times a blood level but it is not always like this.
Sometimes once certain tissues are saturated, the blood level might
rise out of proportion to the increase in dose, and thus the amount in
the milk might rise.

However, if the drug is not causing the mother problems, the blood
levels of paroxetine tend to be *very* low, and the proteing binding
high.

I would suggest to all lactnetters that when a question such as this
comes up, why guess?  Get in touch with a local clinical pharmacology
department and have milk levels tested.  This way, questions can be
answered, at least partially, and you get a paper out of it too.

Jack Newman, MD, FRCPC