Nausea and vomiting of pregnancy (NVP) is one of the most common complaints of women in the early months of gestation. Although most women experience mild- to severe- nausea and occasional vomiting during the first 12 to 15 weeks of pregnancy, some women’s experience with NVP is much more debilitating or longer lasting.

The most severe form of NVP, hyperemesis gravidarum, often requires hospitalization, intravenous hydration and sometimes even intravenous nutritional support.

During the past 30 years, the options for treating NVP have been limited. Advising women to eat small frequent meals of bland foods, utilize acupressure bands for seasickness or try herbal remedies like ginger or peppermint are often first line treatments. These more natural methods can be helpful, but if they fail to offer relief providers often turn to strong anti-nausea drug like ondansetron (Zofran, GlaxoSmithKline), which are commonly used to treat nausea from chemotherapy.

In April of 2013, the FDA approved a drug called Diclegis (Duchesnay Inc.) for the treatment of NVP. It is classified as a Pregnancy Category A drug, which means that well-controlled studies have failed to show any risk to a developing fetus during pregnancy. 

Interestingly, it isn’t a new drug. A similar formulation of doxylamine succinate and pyridoxine hydrochloride (vitamin B6 ) was available in the United States from 1956 until 1983. Sold under the name Bendectin, it was a very effective treatment for NVP.

But the drug became controversial when there were allegations that Bendectin caused birth defects. After careful studies, an FDA panel concluded that there was no association between Bendectin and birth defects. However, Merrell Dow Pharmaceuticals, the company that made and distributed the drug, stopped production due to overwhelming legal costs.

Diclegis has been well studied, making it possibly the most tested pregnancy medication in U.S. history. Even during the 30 years it was unavailable in the U.S. market, it was still available in Canada under the trade name Diclectin (Duchesnay Inc.).  Many providers continued to recommend Unisom, a sleep aid that contains doxylamine succinate, and vitamin B6, as both are available OTC and are essentially the same ingredients Diclegis contains.

Diclegis is currently the only medication FDA approved to treat NVP. Providers should consider this option if more conservative therapies have failed. The primary side effect is drowsiness, so patients should be warned about driving or operating machinery.

Robyn Carlisle, MSN, CNM, WHNP, works as a full-scope midwife at University Doctors and Kennedy University Hospital in Sewell, N.J.