What are the medications for hyperemesis (vomiting) in pregnancy?

From the Guidelines

For hyperemesis in pregnancy, the first-line treatment includes vitamin B6 (pyridoxine) 10-25 mg three times daily, combined with doxylamine 12.5 mg, as recommended by the American College of Obstetricians and Gynecologists (ACOG) 1. The treatment approach should prioritize early intervention to prevent progression to hyperemesis gravidarum (HG). Key considerations in managing hyperemesis include:

• Dietary modifications: eating small, frequent meals, avoiding spicy or fatty foods, and staying hydrated
• Symptom control with vitamin B6 and doxylamine
• Hydration and adequate nutrition
• Prescription antiemetics like promethazine, metoclopramide, or ondansetron may be required in moderate to severe cases, as outlined in the AGA clinical practice update on pregnancy-related gastrointestinal and liver disease 1 It is essential to note that most medications are considered safe in pregnancy, though ondansetron should be used with caution in the first trimester. Severe cases with dehydration may require hospitalization for IV fluids and medication. The Motherisk Pregnancy Unique Quantification of Emesis score (Table 1) can be used to quantify the severity of vomiting during pregnancy, guiding the treatment approach 1. Early treatment and regular dosing are crucial to managing hyperemesis effectively and reducing the risk of complications.

From the Research

Medications for Hyperemesis in Pregnancy

The following medications have been studied for the treatment of hyperemesis in pregnancy:

• Vitamin B6: Recommended in the USA, Canada, and Australia for the treatment of mild to moderate pregnancy sickness and vomiting 2
• Doxylamine: Often used in combination with vitamin B6, and has been shown to be effective in comparison with a placebo 2, 3
• Pyridoxine-doxylamine: A combination of vitamin B6 and doxylamine, which has been shown to be effective in reducing symptoms of nausea and vomiting 3, 4
• Antihistamines: Such as promethazine, which may be used to treat mild to moderate symptoms 3, 4
• Metoclopramide: May be used to treat mild symptoms, but its effectiveness for moderate to severe symptoms is limited 3, 4
• Ondansetron: May be used to treat moderate to severe symptoms, and has been shown to be effective in reducing nausea scores and episodes of emesis 4
• Corticosteroids: May be used to treat severe symptoms, but their use is generally reserved for cases where other treatments have failed 4

Dosage and Administration

The dosage and administration of these medications may vary depending on the specific medication and the severity of symptoms. For example:

• Vitamin B6: May be taken orally in doses of 10mg four times a day, alone or in combination with doxylamine 2
• Pyridoxine-doxylamine: May be taken orally in doses of 10mg/10mg four times a day 3