Over-the-counter medications in pregnancy.

Pregnant women commonly use over-the-counter medications. Although most over-the-counter drugs have an excellent safety profile, some have unproven safety or are known to adversely affect the fetus. The safety profile of some medications may change according to the gestational age of the fetus. Because an estimated 10 percent or more of birth defects result from maternal drug exposure, the U.S. Food and Drug Administration has assigned a risk category to each drug. Many drugs have not been evaluated in controlled trials and probably will not be because of ethical considerations. Of the commonly used over-the-counter medications, acetaminophen, chlorpheniramine, kaolin and pectin preparations, and most antacids have a good safety record. Other drugs, such as histamine H2-receptor blockers, pseudoephedrine, and atropine/diphenoxylate should be used with caution. If use of smoking cessation products is desired, the intermediate-release preparations minimize the amount of nicotine while maintaining efficacy. With all over-the-counter medications used during pregnancy, the benefit of the drug should outweigh the risk to the fetus.