Antihistamines in pregnancy: are they safe?

October 28, 2003

There are no adequate and well-controlled studies in pregnant women for many drugs, including antihistamines. Manufacturers recommend that these drugs be taken during pregnancy "only if clearly needed," for Zyrtec, Claritin, and Benadryl, and "only if the potential benefit justifies the potential risk to the fetus" for Clarinex and Allegra.

Most all of the antihistamines have cautions against use by nursing women because antihistamines are excreted in breast milk.

Benadryl is not recommended for newborn infants, especially premature infants. Zyrtec is listed as safe in pediatric patients aged 6 months to 11 years. Claritin and Allegra are considered safe for children from 6 to 10 years. Literature for Clarinex says that safety of Clarinex for patients under 12 years of age has not been established.

The U.S. Food and Drug Administration (FDA) rates safety of drugs during pregnancy by categories. The footnotes to this article provide a reference to those categories, as well as discussion of the need to find a better way to categorize safety of medications during pregnancy.

Zyrtec, Claritin, and Benadryl are listed as Pregnancy Category B in the FDA ratings. Allegra and Clarinex are listed as Pregnancy Category C.

In our office, we advise pregnant women to follow the advise of the doctor who is managing their pregnancy. He knows best how to assess the need/risk and determine any individualized care needed to assure the unborn baby's safety.

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