Paxil's Birth Defects Warning Strengthened

New Study Links Paxil to Twice as Many Birth Defects as Other Antidepressants

By Miranda Hitti
WebMD Medical News

Reviewed By Michael Smith, MD
on Tuesday, September 27, 2005

Sept. 27, 2005 -- The FDA and the drug company GlaxoSmithKline are alerting doctors about a new study on major birth defects seen in babies born to women who took the antidepressant Paxil during the first trimester of pregnancy.

"Healthcare professionals are advised to carefully weigh the potential risks and benefits of using [Paxil] in women during pregnancy and to discuss these findings as well as treatment alternatives with their patients," the FDA says in a news release.

Paxil Linked to Twice as Many Birth Defects

GlaxoSmithKline recently conducted a study of major birth defects in infants born to women who took antidepressants (including Paxil) during the first trimester of pregnancy.

In a study of more than 3,500 pregnant women, Paxil was linked to twice as many major birth defects as other antidepressants, according to the FDA.

Birth defects are very rare in the U.S., and it's not certain what role, if any, Paxil played in the birth defects seen in the study, notes GlaxoSmithKline.

Changes have been made to the labeling information on pregnancy precautions that accompanies Paxil, says the FDA.

GlaxoSmithKline is a WebMD sponsor.

Most of the birth defects seen in the study were heart related; the most common heart malformations were ventricular septal defects, which are holes between the heart's two main pumping chambers. These are common birth defects overall as well.

The study was a retrospective epidemiological study. That means it looked at large groups of people in hindsight. There was no data on birth defects in babies born to women who didn't take antidepressants during early pregnancy.

From the Company to Doctors

It is "difficult" to determine whether Paxil caused those birth defects, says GlaxoSmithKline in a letter sent to doctors.

In the letter, the company notes that these findings differ from previous studies looking at birth defects and antidepressants.

Data from the large Swedish Medical Birth Registry hasn't shown evidence of increased risk of major birth defects with antidepressants, including Paxil, notes GlaxoSmithKline.

GlaxoSmithKline spokespeople were not immediately available for comment.

Paxil's Warning

Paxil's official web site puts it this way:

"Tell your doctor if you are pregnant or plan to become pregnant as there is a potential risk to the fetus with [Paxil]. Some studies of [Paxil] in pregnant women have suggested a possible increased risk of malformations, while others have not shown such a risk."

Antidepressants, including Paxil and others, such as Prozac and Zoloft, have been linked to withdrawal symptoms in babies born to mothers taking these medications. These antidepressants are known as selective serotonin reuptake inhibitors (SSRIs).

The Paxil web site also says: "Babies born to mothers who have taken antidepressants, including SSRIs such as Paxil, in the third trimester of pregnancy have reported complications, including difficulties with breathing, turning blue, seizures, changing body temperature, feeding problems, vomiting, low blood sugar, floppiness, stiffness, tremor, shakiness, irritability or constant crying. Tube feeding, help with breathing and longer hospitalization may be needed. There have also been reports of premature births in pregnant women exposed to SSRIs, including Paxil.

"Like many antidepressants, Paxil can be present in breast milk so tell your doctor if you are nursing."

SOURCES: News release, FDA. GlaxoSmithKline, "Dear Healthcare Professional."

© 2005 WebMD Inc. All rights reserved.


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