149: Effects of Drugs and Substances on Lactation and Infants

INTRODUCTION

The chapter provides some summary data on medications and substances that may be taken by the mother during pregnancy and/or breast-feeding. Regardless of the designated risk category or presumed safety, no drug or substance should be used during pregnancy and/or breast-feeding unless it is clearly needed and the potential benefits clearly outweigh the risks. The table lists the generic medication name and, in parentheses, the Food and Drug Administration (FDA) fetal risk category followed by the breast-feeding compatibility. At the present time there is no formally FDA-sanctioned breast-feeding category, and the system used here is discussed later. Lastly, any reported effects on lactation or on infant effects based on breast milk consumption are noted. The editorial board has made an attempt to summarize the data based on the best information available for an individual agent where sources disagree. These data are subject to change as new information becomes available. The reader is advised to consult the FDA (www.fda.gov) and manufacturer's web site for the latest information concerning risks of these medications.

U.S. FDA FETAL RISK CATEGORIES

CATEGORY A

Adequate studies in pregnant women have not demonstrated a risk to the fetus in the first trimester of pregnancy; there is no evidence of risk in the last two trimesters.

CATEGORY B

Animal studies have not demonstrated a risk to the fetus, but there are no adequate studies in pregnant women.

     or

Animal studies have shown an adverse effect, but adequate studies in pregnant women have not demonstrated a risk to the fetus during the first trimester of pregnancy, and there is no evidence of risk in the last two trimesters.

CATEGORY C

Animal studies have shown an adverse effect on the fetus, but there are no adequate studies in humans. The benefits from the use of the drug in pregnant women may be acceptable despite its potential risks.

     or

There are no animal reproduction studies and no adequate studies in humans.

CATEGORY D

There is evidence of human fetal risk, but the potential benefits from the use of the drug in pregnant women may be acceptable despite its potential risks.

CATEGORY X

Studies in animals or humans or adverse reaction reports, or both, have demonstrated fetal abnormalities. The risk of use in pregnant women clearly outweighs any possible benefit.

BREAST-FEEDING COMPATIBILITY

As noted, no formal system exists for categorizing drugs or substances and their effect on breast-feeding, lactation, and effects on the infant. The following system is used in this book:

• CATEGORY (+): Generally compatible with breast-feeding.

• CATEGORY (−): Avoid ...