Pregnancy may reduce effects of popular bipolar drug

As any pregnant woman can tell you, pregnancy causes real, physiological changes to the body. What some women may not realize, especially if they're new to pregnancy, is that these changes can spark other changes in the way your body reacts to different substances, such as medications.

One such medication that's affected is lamotrigine, sold under the brand name Lamictal, which is a popular drug used to treat bipolar disorder. Researchers at Northwestern Medicine have discovered that the state of pregnancy can reduce the effectiveness of these drugs, and that this interaction can mean women taking the drug may be more prone to experiencing recurring side effects of bipolar disorder.

Researchers said the reason why the drug loses effectiveness is because the blood concentration of lamotrigine decreases when women become pregnant, which may trigger depressive symptoms. This occurs because women experience a higher metabolism while pregnant.

Doctors don't always predict these changes
According to researchers, one unfortunate side effect of these interrupted physiological processes is that doctors can't or don't always predict when they might occur.

"Now physicians change the dose of the drug in response to women's symptoms worsening. We need to optimize their medication dosing so they stay well," said lead researcher Crystal Clark, M.D. "The safety of the fetus is at risk. Pregnant women that are depressed are less likely to take care of themselves which often leads to poor nutrition, lack of compliance with prenatal care and isolation from family and friends."

According to the study, which was recently published in the American Journal of Psychiatry, 4.4 million women in the U.S. are affected by bipolar disorder, and women of childbearing age experience the highest instances of the condition. Clark said that women with bipolar disorder are more likely to have episodes of depression that recur, and the U.S. Centers for Disease Control and Prevention asserted that instances of depression are linked to premature births, low birth weights and other poor birth outcomes - likely as a result of women failing to take proper care of themselves while pregnant.

Help is available for women at risk
Women who realize they're at risk of experiencing these side effects can be proactive by talking to their prescribing doctors about their concerns. Though there's not much information available regarding dosing adjustments during pregnancy, this study may help physicians make the necessary adjustments to prevent or reduce depressive symptoms in their patients. Researchers advocated specific dosing guidelines to help manage bipolar disorder during pregnancy as well as the postpartum phases in order to reduce symptoms and avoid toxicity to both mother and baby. Instructions for dosing are included in the text of the study report.

Of course, these guidelines aren't as useful if neither physicians nor patients are aware of the risk. Do you think doctors should be more educated about the way certain drugs impact the body differently during pregnancy? Share your feelings in the comments section.