The U.S. Food and Drug Administration announced Thursday in a Drug Safety Communication that it is requiring labeling changes for nonsteroidal anti-inflammatory drugs (NSAIDs). These changes include new labeling to explain that if women take the medications around 20 weeks or later in their pregnancy, the drugs can cause rare but serious kidney problems in the unborn baby, which can lead to low levels of amniotic fluid (the protective cushion surrounding the unborn baby) and the potential for pregnancy-related complications.
NSAIDs include medicines such as ibuprofen, naproxen, diclofenac, and celecoxib. People have taken these drugs for decades to treat pain and fever from many medical conditions. There are both prescription and over-the-counter (OTC) NSAIDs. The medications work by blocking the production of certain chemicals in the body that cause inflammation. Aspirin also is an NSAID; however, these recommendations do not apply to the use of low-dose aspirin (81 mg). Low-dose aspirin may be an important treatment for some women during pregnancy and should be taken under the direction of a health care professional.
“It is important that women understand the benefits and risks of the medications they may take over the course of their pregnancy,” said Patrizia Cavazzoni, M.D., acting director of FDA’s Center for Drug Evaluation and Research. “To this end, the agency is using its regulatory authority to inform women and their health care providers about the risks if NSAIDs are used after around 20 weeks of pregnancy and beyond.”
As noted in the Drug Safety Communication, the warning follows the FDA’s review of the medical literature and cases reported to the agency about low amniotic fluid levels or kidney problems in unborn babies associated with NSAID use during pregnancy.
After about 20 weeks of pregnancy, the unborn baby’s kidneys begin producing most of the amniotic fluid, so fetal kidney problems can cause low levels of this fluid. Low levels of amniotic fluid, a condition known as oligohydramnios, may be detected after taking the medicine for days or weeks, but it may be detected as soon as two days after initiation of regular NSAID use. This condition usually goes away if the pregnant woman stops taking the NSAID.
For prescription NSAIDs, the FDA is requiring changes to the prescribing information to describe the risk of kidney problems in unborn babies that result in low amniotic fluid and to recommend that NSAID use be limited between about 20 weeks to 30 weeks of pregnancy because of this risk. Warnings to avoid taking NSAIDs after about 30 weeks of pregnancy are already included in the prescribing information because taking these medications during this time may lead to heart issues in the unborn baby. If a health care provider believes NSAID use is necessary between about 20 and 30 weeks of pregnancy, use should be limited to the lowest effective dose and shortest duration possible. The manufacturers of OTC NSAIDs intended for adult use will also make similar updates to the Drug Facts labels.
Although certain health care providers treating pregnant women generally know about the risk of low levels of amniotic fluid, the FDA is communicating this information more broadly to educate other health care professionals and pregnant women.