What antacids (anti-acid medications) and proton pump inhibitors (PPIs) are safe to use during the first trimester of pregnancy?

Safe Antacids and Proton Pump Inhibitors for First Trimester Pregnancy

Calcium-based antacids are the preferred first-line choice for acid-related symptoms in the first trimester of pregnancy, with omeprazole being the safest PPI option if antacids fail to control symptoms. 1

Recommended Treatment Algorithm

First-Line: Antacids

• Calcium-containing antacids are the preferred antacid choice during the first trimester (Recommendation Grade A) 1
• Calcium-based antacids provide dual benefits: heartburn relief and calcium supplementation for maternal and fetal bone health without adverse neonatal effects 2
• These agents have minimal systemic absorption, making them particularly safe during the critical first trimester when teratogenic risk is highest 3, 4

Second-Line: Sucralfate

• If symptoms persist despite antacids, sucralfate 1g oral tablet three times daily can be introduced (Recommendation Grade C) 1
• Sucralfate acts locally with minimal systemic absorption 1

Third-Line: H2 Receptor Antagonists

• Histamine-2 receptor antagonists are the next step if antacids and sucralfate are inadequate (Recommendation Grade B) 1
• These have a longer safety track record than PPIs during pregnancy 1

Fourth-Line: Proton Pump Inhibitors

• Omeprazole is the safest PPI choice when severe gastroesophageal reflux disease requires stronger acid suppression (Recommendation Grade C) 5, 1
• PPIs should be reserved for severe conditions that fail to respond to antacids and H2 blockers 5
• Inadequate control with H2 antagonists may mandate stepping up to PPIs along with antacids as rescue medication 1

Important Safety Considerations

General Principles

• The first trimester represents the period of highest risk for medication-induced teratogenicity, and ideally all medications should be avoided when possible 4
• Treatment should follow a step-up approach, starting with lifestyle modifications before any medication 1
• All medication decisions should involve consultation with a physician 1

Specific Warnings

• While long-term PPI use has been associated with potential risks of congenital malformations, omeprazole remains the recommended PPI when necessary 5
• Ensure adequate fluid intake when using any antacid to prevent complications 4
• Antiemetics that are safe in the first trimester include ondansetron, metoclopramide, and meclozine, but corticosteroids should be omitted 3

What to Avoid

• Avoid stimulant laxatives during pregnancy as safety data are conflicting 4
• Long-term PPI use should be avoided unless there is proper indication, particularly in the context of pregnancy 5