To : Pam
Re : venlafaxine (Effexor)

This is from my WEB page concerning venlafaxine and sertraline in
breastfeeding mothers:
--------------------------------

I just received reprints of two nicely-done studies on Zoloft(sertraline)
and Efexor (venlafaxine) from a pharmacologist colleague in Australia. Below
are brief descriptions of the data:

Venlafaxine (Efexor):
Milk:plasma ratio for venlafaxine ranged from 2.8 to 4.8 (average=4.1)at
steady state. The mean total infant dose was 7.6% of the maternal
weight-adjusted dose. The metabolite of venlafaxine (but not venlafaxine)
was detected in all three infants at low levels. The infants were healthy
and showed no acute adverse effects.

Sertraline (Zoloft):
In a group of 8 breastfeeding mothers receiving sertraline, the estimated
dose to infant was 0.9% of sertraline and 1.32% N-desmethylsertraline of
the maternal dose. None was detectible in the plasma of the infants. No
adverse effects were noted in any of the infants and all had achieved normal
developmental milestones.


References:

Kristensen JH, Ilett KF et.al. Distribution and excretion of sertraline and
N-desmethylsertraline in human milk. Br.J.Clin. Pharmacol. 45:453-457,
1998.

Ilett KF, Hackett LP, Dusci LJ, et.al. Distribution and excretion of
venlafaxine and O-desmethylvenlafaxine in human milk. Br. J.Clin.
Pharmacol 45:459-462, 1998.


-------------------


Regards

Tom Hale, R.Ph., Ph.D.

http://neonatal.ttuhsc.edu/lact/