From the Guidelines
For managing nausea and vomiting during pregnancy, a stepwise approach is recommended, starting with non-pharmacological measures and progressing to pharmacological treatments such as pyridoxine, doxylamine, promethazine, metoclopramide, and ondansetron as needed. The initial step in managing nausea and vomiting during pregnancy involves non-pharmacological measures, including eating small, frequent meals, avoiding triggers, consuming ginger (250mg four times daily), and using acupressure bands 1. If these measures are insufficient, pyridoxine (vitamin B6) 10-25mg three times daily can be tried, often combined with doxylamine 12.5mg three times daily 1.
For moderate to severe symptoms, prescription antiemetics may be necessary. The following medications are commonly used:
- Promethazine 12.5-25mg every 4-6 hours
- Metoclopramide 5-10mg three times daily
- Ondansetron 4-8mg every 8 hours, though it should be used cautiously in the first trimester due to potential risks 1. Corticosteroids like methylprednisolone are reserved for hyperemesis gravidarum cases requiring hospitalization. These medications are generally considered safe during pregnancy when used appropriately, with the benefits of treating severe nausea and vomiting typically outweighing potential risks 1.
Adequate hydration should be maintained throughout treatment, and medical attention should be sought if unable to keep fluids down for 24 hours or if experiencing signs of dehydration. The choice of medication should be based on the severity of symptoms, patient preferences, and the potential risks and benefits of each medication, as outlined in recent clinical practice guidelines 1.
From the FDA Drug Label
Available data on ondansetron use in pregnant women from several published epidemiological studies preclude an assessment of a drug-associated risk of adverse fetal outcomes due to important methodological limitations, including the uncertainty of whether women who filled a prescription actually took the medication, the concomitant use of other medications or treatments, recall bias, and other unadjusted confounders.
The FDA drug label does not answer the question about recommended antiemetic medications during pregnancy, as it only discusses the safety of ondansetron use in pregnancy, but does not provide a list of recommended antiemetic medications.
From the Research
Recommended Antiemetic Medications
The following antiemetic medications are recommended for use during pregnancy:
- Ginger, vitamin B6, antihistamines, metoclopramide (for mild symptoms), pyridoxine-doxylamine, and ondansetron (for moderate symptoms) are associated with improved symptoms compared with placebo 2
- Doxylamine-pyridoxine is recommended as a first-line treatment for nausea and vomiting during pregnancy 3, 4
- Pyridoxine (vitamin B6) supplementation has been shown to be beneficial in reducing symptoms of nausea and vomiting during pregnancy 5
- Antihistamines, metoclopramide, ondansetron, phenothiazines, and after the first trimester, corticosteroids are also options for pharmacologic management 6, 4
Medication Safety and Effectiveness
The safety and effectiveness of these medications have been evaluated in various studies:
- Doxylamine-pyridoxine has been given a pregnancy safety rating of A and is recommended as first-line pharmacologic treatment for NVP 4
- Pyridoxine and vitamin B12 are safe and may be effective in treating NVP 6
- Metoclopramide, droperidol, and ondansetron may be effective, but safety data are insufficient to recommend them as first-line agents 6
- Corticosteroids may not be as beneficial as first thought, and there may be a small teratogenic risk 6
Treatment Guidelines
The following treatment guidelines are recommended:
- Nonpharmacologic options, particularly dietary modification, are a mainstay of treatment 4
- Pharmacologic management can be employed for those who continue to experience symptoms 4
- The combination of doxylamine succinate/pyridoxine hydrochloride is recommended as first-line pharmacologic treatment for NVP 4