• 06
  • April
    2011

In our previous post, we began looking at a recent Wall Street Journal article discussing recent warnings concerning safety risks associated with taking certain drugs during pregnancy. Here we continue that discussion.

Evidence concerning the effects of over-the-counter drugs is not much better than evidence on prescription drugs. Some things are generally agreed on. For instance, most doctors believe acetaminophen (Tylenol) is safe for use throughout pregnancy. Antacids are considered to be generally safe, but ones containing sodium bicarbonate may increase bloodstream sodium levels. Nonsteroidal anti-inflammatory drugs, such as aspirin and ibuprofen are considered by many doctors not to be safe, particularly during the third trimester, because of the risk for excess bleeding and other complications. Some studies have linked pseudoephedrine to an increased risk of gastroschisis, a condition in which the baby's intestines grow outside their abdominal wall.

Most experts agree that many chronic conditions cannot go untreated for nine months. Women suffering from asthma, high blood pressure, or depression, for instance, will often continue to take appropriate medications during pregnancy, not only for the mother's health but also for the health of the unborn child. Doctors will often prescribe substitute medications for pregnant women which pose fewer risks, or will advise them to wait until the second trimester to take certain needed medications.

The current system of drug safety rating was established in 1979 by the FDA. That system breaks drugs down into five discrete safety categories based on existing information concerning safety risks. Category A drugs are well established to be safe during pregnancy. Category B drugs are still considered safe, but there is less evidence for their safety. For Category C drugs, there is no available information concerning safety for humans, and more than 60% of drugs fall in this category.

Category D drugs have some known risk of harm to fetus, even if the benefits outweigh the risks in many cases. For Category X drugs, there is either well established information showing risk of harm to humans, or the benefits of the drug are so small that it is not advised to prescribe them for pregnant women. The current system has been criticized because of its openness to interpretation.

In 2008, the FDA proposed a rule which would eliminate the category system and simply requiring drug labels to provide summary of known risks of a drug for pregnant women, as well as clinical information for doctors. According to sources, the rule is currently being finalized.

The FDA is also currently drawing up new guidelines to assist drug manufacturers include pregnant women in clinical trials. In order to assist in gathering safety information, the FDA has encouraged drug makers to establish registries to monitor the effects of prescription medications on pregnant women and their babies. Currently, over 40 such registries exist, and some have already warned FDA as to dangers associated with certain drugs.

Source: Wall Street Journal, "Can Mom's Medicine Hurt the Baby?" Melinda Beck, 28 Mar 2011.