Heart Home > Esmolol and Pregnancy
Based on the results of animal studies, esmolol may cause problems in a developing fetus. Since this drug is often used in emergency situations, however, its benefits may outweigh its potential risks. If pregnancy occurs while you are taking esmolol, your healthcare provider will weigh the benefits and risks before making a recommendation for your situation.
Esmolol hydrochloride (Brevibloc®) is a prescription beta blocker medication approved to treat irregular heart rhythms, rapid heart rates, and low blood pressure during surgery or in emergency situations. Based on the results of animal studies and limited experience with the drug in pregnant women, esmolol may cause problems for a fetus. However, in many cases, the potential benefits of this drug outweigh the potential risks.
The 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.
When given to pregnant rats, esmolol did not cause any problems for the fetal rats, although very high doses were lethal to the pregnant rats (and, therefore, also to the fetal rats). When given to pregnant rabbits, very high doses increased the risk of miscarriages, although this was not seen at lower dosages.
However, it is important to note that animals do not always respond to medicines 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.
With beta blockers in general, there have been reports of slowed intrauterine growth, small placentas, and birth defects related to the use of beta blockers during pregnancy. There have also been reports of a very low heart rate, low blood sugars, and/or decreased breathing in some women when beta blockers were used during childbirth. In particular, there have been slow heart rates in newborns whose mothers were given esmolol during labor or delivery.