This sheet is about exposure to verapamil in pregnancy and while breastfeeding. This information is based on research studies. It should not take the place of medical care and advice from your healthcare providers.
What is verapamil?
Verapamil is a medication that has been used to treat high blood pressure (hypertension), abnormal heart rhythm (arrythmia), and chest pain (angina). It has also been used to treat headaches and migraines, coronary arteriosclerosis (thick and stiff blood vessels near the heart), and kidney disease. Verapamil is in a class of medications called calcium channel blockers. Some brand names for verapamil include Calan®, Covera®, Isoptin®, and Verelan®.
Sometimes when women find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take this medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
Women who are pregnant and have high blood pressure have a greater chance of developing pre-eclampsia (high blood pressure and problems with organs, such as the kidneys) that can lead to seizures (called eclampsia). High blood pressure can increase the chance for medical complications for the woman who is pregnant and for the pregnancy.
I take verapamil. Can it make it harder for me to get pregnant?
Studies have not been done to see if verapamil can make it harder to get pregnant. In some people, verapamil might raise the levels of a hormone called prolactin. When prolactin levels are too high, it can cause the body to make milk even if the woman is not breastfeeding (galactorrhea). Those who have this side effect might have a harder time becoming pregnant.
Does taking verapamil increase the chance of miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Studies have not been done to see if verapamil can increase the chance of miscarriage. One study looking at 78 women who took calcium channel blockers, 32 of which took verapamil, did not find a higher chance for miscarriage.
Does taking verapamil increase the chance of birth defects?
Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like verapamil, might increase the chance of birth defects in a pregnancy. There is not a lot of information about using verapamil during pregnancy. However, most studies looking at women who took verapamil, as well as other calcium channel blockers, did not find a higher chance of birth defects.
Does taking verapamil in pregnancy increase the chance of other pregnancy-related problems?
Some studies have reported a greater chance for preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth) with the use of calcium channel blockers, including verapamil. However, it is not known if these issues are caused by verapamil, the condition being treated, other medications, or other factors. Uncontrolled high blood pressure during pregnancy has been associated with a greater chance of preterm delivery and low birth weight.
Two studies did not find long term effects in heart function of 40 newborns after prenatal exposure to verapamil later in pregnancy to treat high blood pressure or premature labor.
People with high blood pressure have a greater chance of developing pre-eclampsia (high blood pressure and problems with organs, such as the kidneys) that can lead to seizures (called eclampsia).
Does taking verapamil in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if verapamil can increase the chance of behavior or learning issues for the child.
Breastfeeding while taking verapamil:
Verapamil passes into breast milk in small amounts. Three babies (ages 13 days, 8 weeks, and 3 months) who were exposed to verapamil through breast milk did not have any problems.
The product label for verapamil recommends women who are breastfeeding not use this medication if breastfeeding. This is because there is not enough information on how the verapamil in breast milk might affect a nursing infant. But the benefits of using verapamil and breastfeeding might outweigh possible risks. Your healthcare providers can talk with you about using verapamil and what treatment is best for you. Be sure to talk to your healthcare provider about all your breastfeeding questions.
If a man takes verapamil, could it affect his fertility or increase the chance of birth defects?
Some men who took verapamil had problems like getting or keeping an erection and lower interest in sex (low sex drive) which may affect male fertility (ability to get a woman pregnant). These problems went away after they stopped taking the medication. Other men who took verapamil did not have these issues. In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
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