What are the recommended medications for nausea during pregnancy?

Recommended Medications for Nausea During Pregnancy

For nausea and vomiting during pregnancy (NVP), first-line pharmacologic treatment should include vitamin B6 (pyridoxine) 10-25 mg every 8 hours, which can be combined with doxylamine 10 mg as needed for persistent symptoms. 1

Understanding NVP

Nausea and vomiting affects 30-90% of pregnant women, typically:

• Beginning at 4-6 weeks gestation
• Peaking at 8-12 weeks
• Usually subsiding by week 20

The severity can be assessed using the Motherisk Pregnancy Unique Quantification of Emesis (PUQE) score, which categorizes symptoms as mild (≤6), moderate (7-12), or severe (≥13).

Treatment Algorithm

Step 1: Non-pharmacologic Interventions

• Dietary modifications:
  • Small, frequent, bland meals
  • BRAT diet (bananas, rice, applesauce, toast)
  • High-protein, low-fat meals
  • Avoid spicy, fatty, acidic, and fried foods
• Identify and avoid specific triggers (foods with strong odors, activities)

Step 2: First-line Pharmacologic Treatment (Mild Symptoms)

• Ginger 250 mg capsules four times daily 1
• Vitamin B6 (pyridoxine) 10-25 mg every 8 hours 1, 2
  • Studies show significant improvement in nausea scores and reduction in vomiting with vitamin B6 supplementation 3, 2

Step 3: For Persistent or Moderate Symptoms

• Doxylamine-pyridoxine combination:
  • Available in 10 mg/10 mg or 20 mg/20 mg combinations 1
  • FDA-approved and recommended by ACOG for persistent NVP 1
  • Can be taken preemptively to reduce risk of recurrence of moderate-severe symptoms 4

Step 4: For Moderate to Severe Symptoms

• H1-receptor antagonists (safe first-line pharmacologic antiemetic therapies) 1:
  • Promethazine
  • Dimenhydrinate
• Metoclopramide (for mild to moderate symptoms) 4
• Ondansetron (for moderate symptoms) 4
  • One study showed ondansetron was associated with lower nausea scores than metoclopramide 4

Step 5: For Severe Symptoms/Hyperemesis Gravidarum

• Corticosteroids may be considered for severe cases refractory to other treatments 4
• May require hospitalization for IV hydration and electrolyte management

Important Considerations

1. Early intervention is key: Prompt treatment may prevent progression to hyperemesis gravidarum 1

2. Safety profile:

   • Vitamin B6 is established as safe during pregnancy at doses up to 40-60 mg/day 5
   • Doxylamine-pyridoxine combinations are well-tolerated in pregnancy 1

3. Hyperemesis gravidarum warning signs:

   • Dehydration
   • Weight loss >5% of prepregnancy weight
   • Electrolyte imbalances
   • Intractable vomiting

4. Medication efficacy:

   • While the combination of doxylamine-pyridoxine shows statistical improvement over placebo, the clinical significance may be modest 6
   • The quality of evidence for most interventions is generally low 4

5. Avoid during pregnancy:

   • Medications used for other conditions like ACE inhibitors, angiotensin receptor blockers, and statins should be avoided during pregnancy 1

By following this stepwise approach, most pregnant women with nausea and vomiting can achieve symptom relief while minimizing risks to both mother and fetus.