The US Food and Drug Administration (FDA) has approved another medication for the management of pregnancy-related nausea and vomiting.  It is not really a new medication but is similar to Diclegis, a combination doxylamine succinate and pyridoxine hydrochloride (vitamin B6), which was approved several years ago.  

The newly approved medication will be marketed as Bonjesta.  Each tablet contains 20 mg of doxylamine succinate, an antihistamine, and 20 mg of pyridoxine HCl, a vitamin B6 analog.  It is essentially a higher dose formulation of Diclegis, which contains doxylamine succinate 10 mg and pyridoxine HCl 10 mg.  Bonjesta will be available in an extended-release preparation to be taken once daily at bedtime.  

Diclegis and Bonjesta are related to Benectin, a similar combination previously used for morning sickness but pulled from the market in 1983 because there were concerns regarding its reproductive safety.  (Bendectin originally contained dicyclomine which was later removed due to lack of efficacy.)

While there have been concerns regarding safety, two separate meta-analyses have assessed pregnancy outcomes following first trimester exposure to the combination of pyridoxine and doxylamine (with and without dicyclomine).  The first meta-analysis, published in 1988, combined data from 12 cohort and 5 case-control studies, and the subsequent meta-analysis, published in 1994, combined data from 16 cohort studies and 11 case control studies. These studies included over 200,000 Bendectin-exposed pregnancies and did not observe an increased risk for major malformations.

Beneficial Side Effects?

While psychiatrists are not typically on the front line for managing nausea and vomiting, these symptoms can have a profoundly negative effect on mood and sleep.  The most commonly reported side effect for the combination of doxylamine and pyridoxine is somnolence.  Obviously this can be a problem in some women, but I have noticed that some women with pregnancy-related nausea and vomiting do very well with Diclegis, because it improves nausea and, at the same time, improves sleep.  

The combination of doxylamine and pyridoxine was not created (nor FDA-approved) for the management of insomnia, but given the well characterized reproductive safety profile of this medication, one wonders if it might be useful during pregnancy for the treatment of insomnia, as well as the management of nausea and vomiting.  


Ruta Nonacs, MD PhD

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