From the Guidelines
Doxylamine succinate (Unisom) combined with vitamin B6 (pyridoxine) is effective for treating pregnancy-related nausea and vomiting, with a recommended dosage of 10-25 mg of vitamin B6, and the American College of Obstetricians and Gynecologists supports this treatment approach 1. The combination of doxylamine and vitamin B6 is considered first-line therapy for morning sickness and has been shown to reduce nausea and vomiting in pregnant women.
- Doxylamine works as an antihistamine that affects the central nervous system,
- while vitamin B6 helps with proper nervous system function and may directly impact nausea centers in the brain. This combination is generally considered safe during pregnancy, though it may cause drowsiness, so taking it at bedtime is often recommended. Some women may need to adjust the dosing schedule to three times daily (with lower doses of doxylamine during daytime) for better symptom control. Always consult with a healthcare provider before starting this or any medication during pregnancy to ensure appropriate dosing and to rule out more serious conditions like hyperemesis gravidarum that may require different treatment, as supported by recent guidelines 1.
From the Research
Effectiveness of Unisom B6 for Nausea
- Unisom (doxylamine succinate) B6 15 mg is a combination of doxylamine and vitamin B6, which has been studied for its effectiveness in treating nausea, especially during pregnancy 2, 3.
- Studies have shown that vitamin B6, often in combination with doxylamine, is effective in treating mild to moderate nausea and vomiting during pregnancy 2.
- The combination of doxylamine and pyridoxine (a vitamin B6 analog) has been approved by the US Food and Drug Administration (FDA) for the treatment of nausea and vomiting in pregnancy 3.
Safety and Dosage
- The harmlessness of oral vitamin B6 during pregnancy has been established for doses up to 40-60mg/day, mainly in combination with doxylamine 2.
- A study suggests that doxylamine-pyridoxine is safe and effective for treating nausea and vomiting in pregnancy, with a recommended dosage of 10mg of doxylamine and 10mg of pyridoxine 3.
- However, another study raises concerns about the safety of doxylamine-pyridoxine, citing limited evidence of its effectiveness compared to pyridoxine alone and potential links to pyloric stenosis and childhood malignancies 4.
Comparison to Other Treatments
- Other studies have found that pyridoxine (vitamin B6) alone may be safe and effective for treating nausea and vomiting in pregnancy 5, 4.
- Antihistamine (H1) blockers, phenothiazines, and other medications may also be safe and effective for treating nausea and vomiting in pregnancy, but their effectiveness and safety compared to doxylamine-pyridoxine are not well established 5.