A new study suggests that side effects of Paxil, Effexor and other antidepressants could increase the risk of a miscarriage for pregnant women.
Researchers from the University of Montreal found that women were about 68% more likely to have a spontaneous abortion if they used a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). If they took more than one class of antidepressant, the risk of having a miscarriage doubled. The results of the study were published online May 31 by CMAJ, the medical journal of the Canadian Medical Association.
Researchers looked at nearly 70,000 pregnant women and found 241 women who had been prescribed antidepressants during pregnancy and had spontaneous abortions. Compared to a matched control group of 1,401 women, they determined that the rate of spontaneous abortion among women given antidepressants, including Paxil and Effexor, was 5.5%, versus 2.7% in women who were not given antidepressants.
When the researchers grouped women by the type of antidepressant they used, Paxil and Effexor were the two SSRIs that seemed to have the strongest connection to miscarriage.
“A higher mean daily dose of [Paxil] or [Effexor] was associated with an increased risk of spontaneous abortion, consistent with a dose-response relationship,” the researchers concluded.
Researchers found that the numbers increased when women were given more than one class of antidepressant, doubling the risk of miscarriage.
Paxil (paroxetine) is an SSRI prescribed to treat depression. Approved in 1992, it has become one of the most commonly prescribed drugs in the United States, with sales of just under $1 billion in 2008.
GlaxoSmithKline has reportedly paid about $1 billion to settle lawsuits over Paxil, which have included allegations of birth defects and suicide. And with hundreds of Paxil birth defect lawsuits still pending, the company is likely to spend substantially more to satisfy jury verdicts or settle all Paxil cases.
Effexor (venlafaxine), was first created by Wyeth in 1993 for the treatment of major depressive disorder and anxiety disorders. It was the sixth best selling antidepressant in the U.S. in 2007, with more than 17 million prescriptions. It is also sold under the brand names of Efexor, Alventa, Argofan and Trevilor.