What are the recommended antinausea medications for pregnant women?

From the Guidelines

Pregnant women experiencing nausea and vomiting should be treated with vitamin B6 (pyridoxine) 10-25mg three times daily, combined with doxylamine (an antihistamine) 12.5mg three to four times daily, as first-line treatment. These medications can be taken separately or as the combination product Diclegis/Diclectin 1. For women with more severe symptoms, prescription antiemetics such as metoclopramide 5-10mg three times daily, promethazine 12.5-25mg every 4-6 hours, or ondansetron 4-8mg every 8 hours may be used 1. Ginger supplements (250mg four times daily) can also provide relief with minimal side effects. Some key points to consider when treating nausea and vomiting in pregnant women include:

• Early treatment of nausea and vomiting of pregnancy may reduce progression to hyperemesis gravidarum 1
• Women should stay hydrated, eat small frequent meals, and avoid triggers like strong odors
• Medical attention should be sought immediately if unable to keep fluids down for 24 hours or if experiencing signs of dehydration
• The benefits of these medications outweigh potential risks when nausea and vomiting are severe enough to affect nutrition and hydration 1 It's essential to note that the safety and efficacy of these medications during pregnancy have been established, and they are considered compatible with pregnancy, breastfeeding, and paternal exposure 1. However, it's crucial to weigh the benefits and risks of each medication on a case-by-case basis, considering the severity of symptoms and individual patient needs.

From the FDA Drug Label

Published epidemiological studies on the association between ondansetron use and major birth defects have reported inconsistent findings and have important methodological limitations that preclude conclusions about the safety of ondansetron use in pregnancy Available postmarketing data have not identified a drug associated risk of miscarriage or adverse maternal outcomes. Reproductive studies in rats and rabbits did not show evidence of harm to the fetus when ondansetron was administered during organogenesis at approximately 6 and 24 times the maximum recommended human oral dose of 24 mg/day, based on body surface area (BSA), respectively

The recommended antinausea medication for pregnant women is ondansetron. However, the safety of ondansetron use in pregnancy is not conclusively established due to inconsistent findings and methodological limitations in epidemiological studies 2.

• Key points:
  • No drug-associated risk of miscarriage or adverse maternal outcomes was identified in postmarketing data.
  • Animal studies did not show evidence of harm to the fetus when ondansetron was administered during organogenesis. It is essential to consult a healthcare provider to determine the best course of treatment for nausea during pregnancy.

From the Research

Antinausea Medications for Pregnant Women

The following are recommended antinausea medications for pregnant women:

• Doxylamine succinate-pyridoxine hydrochloride (Diclegis) 3, which is currently the only FDA-approved medication for the treatment of nausea and vomiting in pregnancy
• Pyridoxine (Vitamin B6) supplementation, which has been shown to be effective in reducing symptoms of nausea and vomiting in pregnancy 4
• Ginger, which has been associated with improved symptoms compared to placebo for mild symptoms of nausea and emesis of pregnancy 5
• Antihistamines, which have been associated with greater benefit than placebo for mild symptoms of nausea and emesis of pregnancy 5
• Metoclopramide, which has been associated with greater benefit than placebo for mild and moderate symptoms of nausea and emesis of pregnancy 5
• Ondansetron, which has been associated with improvement for a range of symptom severity 5
• Corticosteroids, which may be associated with benefit in severe cases of nausea and vomiting in pregnancy 5

Safety and Efficacy

The safety and efficacy of these medications have been studied in various clinical trials:

• A systematic review and meta-analysis found that pyridoxine supplementation significantly improved symptoms of nausea and vomiting in pregnancy 4
• A randomized controlled trial found that doxylamine-pyridoxine was associated with greater improvement in symptoms scores compared to placebo, although the difference was not statistically significant using all approaches to missing data 6
• A review of the pharmacologic management of nausea and vomiting of pregnancy found that the combination of doxylamine succinate/pyridoxine hydrochloride is recommended as first-line pharmacologic treatment for NVP, with a pregnancy safety rating of A 7

Treatment Approach

The treatment approach for nausea and vomiting in pregnancy typically involves a hierarchical approach, with nonpharmacologic options such as dietary modification being tried first, followed by pharmacologic management if symptoms persist:

• The combination of doxylamine and pyridoxine should be considered as a first-tier option for the management of nausea and vomiting in pregnancy 3
• Other medications such as antihistamines, metoclopramide, and ondansetron may be considered for mild to moderate symptoms, while corticosteroids may be considered for severe cases 5