Revia and Pregnancy
Although Revia (naltrexone) has not been adequately studied in pregnant women, in animal studies, the drug appeared to increase the risk for miscarriage and other problems. Due to the potential risks, a healthcare provider should only prescribe Revia to a pregnant woman if the benefits of using the drug outweigh the potential risks to the unborn child.
Revia® (naltrexone) is a prescription medication used in the treatment of alcohol and drug addiction. Based on animal studies, Revia may not be safe for use during pregnancy.
The U.S. Food and Drug Administration (FDA) uses a category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Revia is classified as a pregnancy Category C medication.
Pregnancy Category C is given to medicines that have not been adequately studied in pregnant humans but do appear to cause fetal harm in animal studies. In addition, medicines that have not been studied in any pregnant women or animals are automatically given a pregnancy Category C rating.
Revia has not been adequately studied in pregnant women. Based on the properties of the drug, it is expected to cross the placenta, which means a developing fetus would likely be exposed to the medication if it was taken by a pregnant woman.
In animal studies, Revia did not appear to cause birth defects when given to pregnant rats or rabbits, even at doses that were equivalent to 65 times the usual recommended human dose. However, the drug increased the risk for miscarriage in the pregnant animals. When given to male and female rats during mating, fewer female rats become pregnant. In addition, rats exposed to the medication while they were fetuses were less sensitive to the pain-relieving effects of morphine later in life.
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, including Revia, may be given to a pregnant woman if her healthcare provider believes that the benefits to the woman outweigh any possible risks to her unborn child.