From the Guidelines
The recommended dose for treating hyperemesis gravidarum is typically 10 mg of doxylamine combined with 10 mg of pyridoxine (vitamin B6) taken three to four times daily. This combination is often prescribed as Diclegis or Bonjesta in the United States, which are delayed-release formulations, as recommended by the American College of Obstetricians and Gynecologists (ACOG) 1. Treatment usually begins with two tablets at bedtime, which can be increased to a maximum of four tablets daily (one in the morning, one in the afternoon, and two at bedtime) if symptoms persist.
Key Considerations
- For women who cannot access the combination product, taking the components separately is an alternative—10 mg doxylamine (available over-the-counter as Unisom SleepTabs) and 10-25 mg vitamin B6 three times daily, as suggested by the study 1.
- This regimen works by combining the antihistamine effects of doxylamine, which reduces nausea, with vitamin B6, which has been shown to help alleviate pregnancy-related nausea.
- The medication should be taken consistently rather than as needed for optimal effect.
- Common side effects include drowsiness, so caution should be exercised when driving or operating machinery, especially when starting treatment.
Treatment Approach
- Diet and lifestyle modification are the initial steps in managing these symptoms in pregnancy, including reducing spicy, fatty, acidic, and fried foods to help reduce heartburn, and eating small, frequent, and bland meals 1.
- Specific triggers, such as certain foods with strong odors or activities, should be identified and avoided.
- If symptoms are persistent or severe, therapeutic options include ginger (a 250-mg capsule 4 times daily) and vitamin B6 (pyridoxine, 10–25 mg every 8 hours), as recommended by ACOG 1.
From the Research
Recommended Dose of Doxylamine and Vitamin B6
- The recommended dose of doxylamine and vitamin B6 for treating hyperemesis gravidarum is doxylamine succinate 10 mg and pyridoxine hydrochloride 10 mg, taken as a delayed-release combination pill 2.
- This combination is available as Diclegis, which is the only medication FDA-approved for the indication of nausea and vomiting in pregnancy 2, 3.
- The dosage of Diclegis is one tablet taken at bedtime, and if symptoms persist, a second tablet can be taken in the morning, and a third tablet can be taken at bedtime if needed, but no more than three tablets per day 3.
Efficacy of Doxylamine and Vitamin B6
- Studies have shown that doxylamine and pyridoxine are effective in reducing symptoms of nausea and vomiting in pregnancy, including hyperemesis gravidarum 4, 5.
- The combination of doxylamine and pyridoxine has been shown to be more effective than placebo in reducing symptoms of nausea and vomiting 4, 5.
- Doxylamine and pyridoxine are considered a first-tier treatment option for nausea and vomiting in pregnancy, due to their safety and efficacy 2.