The safety of doxylamine and pyridoxine combination for nausea and vomiting of pregnancy

Doxylamine succinate-pyridoxine hydrochloride delayed release combination is safe to be used by pregnant women in the recommend does of up to 4 tablets per day to treat nausea and vomiting during pregnancy.

Nausea and vomiting of pregnancy (NVP) is very common, affecting around 80% of expecting mothers. Lifestyle changes may be helpful but many women still need medications to control their symptoms. The Food and Drug Administration (FDA) approved the delayed release combination of doxylamine succinate and pyridoxine hydrochloride (Diclegis®, an identical combination to the original Bendectin® and its Canadian equivalent Dicletin®) for nausea and vomiting in 2013, following a phase 3 randomized trial in pregnant women. The fetal safety has been proven by several studies but because it is the only FDA-approved medication for NVP that is likely to be used by a large number of pregnant women, its maternal safety is an important concern. The purpose of this study was to evaluate the maternal safety of Diclegis® delayed-released preparation.

This is a secondary analysis of a double-blind, randomized, multicenter, placebo-controlled study of the delayed release combination of doxylamine succinate (10 mg) and pyridoxine hydrochloride (10 mg) (Diclegis®) in the treatment of NVP. Women were randomly selected to receive Diclegis® (n = 131) or placebo (n = 125) for 2 weeks at doses ranging from 2-4 tablets a day, based on a pre-specified titration protocol response to symptoms. The subjects were pregnant (≥ 18 years of age), in the gestational age range of 7-14 weeks and suffering from NVP. Adverse events were collected through patient diaries, clinical examination and laboratory testing. Results showed that the use of doxylamine succinate and pyridoxine hydrochloride was not associated with an overall increased rate of adverse effects as compared to the placebo group. Diclegis® was also not related to either more frequently occurring adverse events or with an increase in Treatment Emergent Adverse Events (TEAEs), as defined by the investigators, blinded to study drug allocation.

Based on the results, it can be concluded that doxylamine succinate-pyridoxine hydrochloride delayed release combination is safe to be used by pregnant women in the recommend does of up to 4 tablets per day to treat nausea and vomiting during pregnancy.

References

  1. Koren, G., et al., Maternal safety of the delayed-release doxylamine and pyridoxine combination for nausea and vomitting of pregnancy; a randomized placebo controlled trial. BMC Pregnancy Childbirth, 2015.