Evaluation of the Efficacy and Safety of Bi-Daily Combination Therapy with Pyridoxine and Doxylamine for Nausea and Vomiting of Pregnancy

Background: Diclectin (R) (pyridoxine 10 mg and doxylamine 10 mg) has traditionally been used to treat nausea and vomiting of pregnancy (NVP); however, this drug is unavailable in many countries. Objectives: To evaluate the efficacy and safety of a simple bi-daily treatment regimen with the combination of pyridoxine (50 mg twice daily) and doxylamine (25-50 mg) as an alternative treatment for NVP. Methods: A prospective case-controlled observational study of mother-infant pairs was conducted between February 2008 and December 2010. All women who contacted the Beilinson Teratology Information Service (BELTIS) regarding treatment of NVP were eligible for inclusion. Using data on NVP severity, treatment efficacy and outcomes, we compared the two groups of women: those treated with the combination of pyridoxine and doxylamine (treatment group, n=29) and those treated with metoclopramide (control group, n=29). Results: Moderate to severe symptoms were present in 97% of the treatment group women vs. 69% of control group women (P < 0.01). Despite increased symptom severity in the treatment group, the combination regimen was efficacious: 20/29 (69%) vs. 18/25 (72%) in the treatment vs. control women respectively (P = 0.65). There were no congenital anomalies in the treatment group. Follow-up was normal for all infants. Conclusions: Bi-daily combination therapy with pyridoxine and doxylamine for NVP is safe, has comparable efficacy to metoclopramide, and is a treatment alternative in countries where Diclectin is not available. Despite symptoms warranting counseling by a teratology information service, more than a third of women do not take the suggested treatment. IMAJ 2013; 15:23-26