Having a Baby? Get to Know the FDA Drug Classifications

January 27th, 2010. By Kristine B

Navigating the complex web of drug categories can be complex and overwhelming. Add to that the pregnancy categories and it can be tough to determine just which drugs a pregnant woman should and shouldn’t take. This week, Pleading Ignorance looks at the different FDA pregnancy categories. 

How Does the FDA Classify Drugs for Pregnancy? 

Basically, the categories are based on studies, including animal studies, human studies and/or post-marketing data (reports that have come in after a drug is released on the market). Information taken from those studies—including adverse reactions and potential side effects—is then used to put the drug into a pregnancy category. 

Now, although the categories may seem straight-forward (they are all letters) they aren’t necessarily that simple. Some drugs might have a higher impact on the fetus depending on the point at which they’re taken during pregnancy. Other drugs might have a higher risk of abnormality depending on the dosage taken. When it comes to taking medications while pregnant it’s important for pregnant women to discuss their options with their doctor to determine if the benefits outweigh the risks. 

Also, keep in mind that as increased post-marketing data for a drug becomes available, the FDA can change a drug’s pregnancy category. So, a drug may start out in Category B, for example, but be moved to a Category C if there is enough evidence of an increase in risk after the drug is approved for use. 

FDA Drug Classifications for Pregnancy

So, here’s how it breaks down: 

Category A: Means that controlled studies have found no risk to the fetus when the mother takes the medication during any trimester of pregnancy. 

Category B: Means that controlled studies in pregnant women have not shown an increased risk of fetal abnormalities, although some adverse findings have occurred in animals. It can also mean that there are no adequate human studies but animal studies show no fetal risk. There is a remote possibility of fetal harm. 

Category C: Means that there is a risk. Either there are not enough adequate human studies, but animal studies have shown a risk or there are not adequate animal studies. There is a chance of fetal harm but benefits may outweigh the risks. 

Category D: Human studies and/or adverse reaction data have shown evidence of fetal risk but the benefits of use may outweigh the potential risks. Paxil and Depakote are both considered Pregnancy Category D drugs because they could cause harm to an unborn baby.

Category X: Studies in animals or humans or other reports have shown evidence that babies exposed to this medication prior to birth have a risk of abnormalities that outweighs any benefit to the patient. In a nutshell—do not take a Category X drug while you are pregnant. 

Now, keep in mind that this does not mean that a drug in Category X has a higher risk of abnormalities than a drug in Category D. It simply means that the risks outweigh any potential benefits. 

Also, it is important to remember that even if you are taking a drug in Category D or Category X, you should not stop taking your medication without first speaking with your doctor. There are risks associated with stopping medication too abruptly that may also cause harm to your newborn. 

If you are taking a medication and would like to know what the drug’s Pregnancy Category is, sites like drugs.com provide detailed information about medications, including their FDA pregnancy rating. Simply type the name of the medication in the search field and select the “consumer information” from the list of articles that the search returns.

Upcoming Changes to the FDA Pregnancy Classifications for Drugs

Now that you have an understanding of all that, the FDA has announced that it will revise its pregnancy and lactation labeling because the current labeling is overly simplistic and does not adequately reflect data from studies. The proposed labeling would include three components, a risk summary, clinical considerations and a data section. 

The risk summary would include information on whether the drug was studied in humans or animals, and would provide the most important data concerning the effects the drug has on the fetus. Clinical considerations include information on dose, timing and length of exposure, and prescribing decisions for pregnant women (such as any interventions, drug effects during labor, and complications for the fetus). Finally, the data section would include a more detailed discussion of the data from human and animal studies. 

However, until those changes are made, it’s good have an understanding of how the current classification system works. 

Tags: FDA, FDA Drug Classification, Pleading Ignorance

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