Calcium Channel Blockers and Pregnancy
The FDA has classified calcium channel blockers as pregnancy Category C medications, meaning they may not be safe for use during pregnancy. In animal studies of calcium channel blockers and pregnancy, the drugs were shown to cause certain problems. However, animals do not always respond to medicines in the same way that humans do, and a healthcare provider can still prescribe the drug if the benefits outweigh the risks.
An Overview of Calcium Channel Blockers and PregnancyFor people who are pregnant, calcium channel blockers may not be safe. This is based on animal studies that looked at the effects of taking calcium channel blockers during pregnancy.
Calcium Channel Blockers and Pregnancy Category CThe U.S. Food and Drug Administration (FDA) uses a pregnancy category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Pregnancy Category C is given to medicines that have not been studied in pregnant humans, but do appear to cause harm to the fetus in animal studies. Also, medicines that have not been studied in any pregnant women or animals are automatically given a pregnancy Category C rating.
Calcium channel blockers were given a pregnancy Category C rating because of potential problems in animal studies.
However, it is important to note that animals do not always respond to medicines in the same way that humans do. Therefore, a pregnancy Category C medicine may be given to a pregnant woman if the healthcare provider believes that the benefits to the pregnant woman outweigh any possible risks to the unborn child.
Certain calcium channel blockers are sometimes used to stop preterm labor, especially when other medications have failed. Calcium channel blockers help to relax the smooth muscle of the uterus, stopping premature labor. Because none of the calcium channel blockers are approved for treating preterm labor, this is considered an "off-label" use.