UpToDate
Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Medline ® Abstract for Reference 51

of 'Safety of infant exposure to antidepressants and benzodiazepines through breastfeeding'

51
TI
Distribution and excretion of venlafaxine and O-desmethylvenlafaxine in human milk.
AU
Ilett KF, Hackett LP, Dusci LJ, Roberts MJ, Kristensen JH, Paech M, Groves A, Yapp P
SO
Br J Clin Pharmacol. 1998;45(5):459.
 
AIMS: To characterise the transfer of venlafaxine (V) and its O-desmethyl metabolite (ODV) into human milk by measuring milk/plasma (M/P) ratio, and to estimate the likely dose received by a breast-fed infant.
METHODS: Milk and plasma samples were collected from three lactating women who were taking venlafaxine for depression, and were at steady-state. In two of the patients, venous blood and milk samples were collected 0, 1, 2, 3, 4, 6, 8 and 12 h post dose, while in the third patient a single pair of blood and milk samples was obtained 0.83 h post dose. A plasma sample was obtained from each of their infants. V and ODV were measured in plasma and milk by high performance liquid chromatography. M/P was calculated and infant dose estimated as drug concentration in milk x a milk intake of 0.15 l kg(-1) day(-1), relative to the weight-adjusted maternal dose.
RESULTS: Mean M/P for V was 4.1 (range 2.8-4.8) and 3.1 for ODV (range 2.8-3.8). The mean total infant dose (as V equivalents) was 7.6% (range 4.7-9.2%) of the maternal weight-adjusted dose, with approximately equal amounts of V (3.5%) and ODV (4.1%) in the dose. ODV (median100 microg I(-1)) was detected in the plasma of all three infants. The infants were healthy and showed no acute adverse effects.
CONCLUSIONS: These preliminary data show that the total dose of V and ODV ingested by breast-fed infants can be as high as 9.2% of maternal intake. Moreover there were measurable concentrations of ODV in the infants' plasma. We recommend that exposed infants should be observed closely.
AD
Department of Pharmacology, University of Western Australia, Nedlands.
PMID