Bipolar drugs lose effect during pregnancy, so women need higher doses to stay well
New Northwestern Medicine- research offers one of the first in-depth studies of how physiological changes during pregnancy reduce the effects of a commonly used drug to treat bipolar disorder, making women more vulnerable to recurring episodes. The new findings will help psychiatrists and physicians prevent bipolar manic and depressive symptoms during pregnancy, which are risky for the health of the mother and her unborn child.
When a woman with bipolar disorder becomes pregnant, she and her physician often don't realize her medication needs adjusting to prevent the symptoms from coming back - a higher risk during pregnancy. There also is little information and research to guide dosing for psychiatric medications during pregnancy.
Approximately 4.4 million women in the U.S. have bipolar disorder with women of childbearing age having the highest prevalence.
The new study shows the blood concentration of the commonly used drug lamotrigine decreases in pregnant women. About half of the women in the study had worsening depressive symptoms as their lamotrigine blood levels dropped. The drug levels fall because women have increased metabolism during pregnancy.
"Now physicians change the dose of the drug in response to women's symptoms worsening," said lead investigator Crystal Clark, M.D., an assistant professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine and a psychiatrist at Northwestern Memorial Hospital. "We need to optimize their medication dosing so they stay well."