What are the recommended antacids (anti-acid medications) for pregnant women with heartburn or acid reflux?

Antacids in Pregnancy

For pregnant women with heartburn or acid reflux, calcium-containing antacids are the preferred first-line pharmacological treatment, followed by sucralfate if symptoms persist, then H2-receptor antagonists (particularly ranitidine or famotidine), with proton pump inhibitors reserved for severe or refractory cases. 1, 2, 3

Treatment Algorithm

Step 1: Lifestyle and Dietary Modifications (First-Line)

• Reduce intake of spicy, fatty, acidic, and fried foods 4
• Consume small, frequent meals rather than large meals 4
• Identify and avoid specific trigger foods, particularly those with strong odors 4
• Elevate the head of the bed and avoid lying down immediately after eating 1, 2

Step 2: Calcium-Containing Antacids (First-Line Pharmacological)

• Calcium-containing antacids are the preferred first-line medication 1
• These provide rapid symptom relief and are considered safe throughout pregnancy 1, 2
• Avoid aluminum-containing antacids as they can interfere with medication absorption 5
• When using magnesium or aluminum-containing antacids with other medications, consider timing to avoid absorption interference 5

Step 3: Sucralfate (Second-Line)

• If symptoms persist despite antacids, add sucralfate 1g orally three times daily 1, 2
• Sucralfate has demonstrated superior efficacy compared to lifestyle modifications alone, with complete heartburn relief in significantly more women (RR 2.41,95% CI 1.42 to 4.07) 6
• Considered safe throughout pregnancy 2, 3

Step 4: H2-Receptor Antagonists (Third-Line)

• If inadequate control with antacids and sucralfate, escalate to H2-receptor antagonists 1, 2
• Ranitidine is the preferred H2-receptor antagonist due to documented efficacy and safety profile, even in the first trimester 2
• Famotidine is classified as FDA Pregnancy Category B 5
• All H2-receptor antagonists can be used during pregnancy, but ranitidine has the most robust safety data 2, 3

Step 5: Proton Pump Inhibitors (Reserved for Severe Cases)

• PPIs are reserved for women with intractable symptoms or complicated reflux disease 2, 3
• Lansoprazole may be the preferred PPI due to its safety profile in animal studies and human case reports 2
• All PPIs except omeprazole are FDA Category B drugs during pregnancy 3
• Should only be used after consultation with a physician 1

Key Clinical Pearls

Timing and Progression

• Symptomatic GERD typically presents in the first trimester and progresses throughout pregnancy 1
• Approximately two-thirds of pregnant women develop heartburn, with 25% experiencing daily symptoms 1, 2
• Early treatment is essential to prevent progression to more severe symptoms 4

Safety Considerations

• Serious reflux complications during pregnancy are rare, so invasive diagnostic tests like endoscopy are infrequently needed 2, 3
• Antacids can be used as rescue medication for breakthrough symptoms even when on higher-tier therapy 1
• The treatment goal is to alleviate symptoms without jeopardizing pregnancy outcomes 1

Common Pitfalls to Avoid

• Do not delay pharmacological treatment if lifestyle modifications are insufficient—early intervention prevents symptom progression 4, 1
• Do not use aluminum-containing antacids as first choice due to absorption interference concerns 5
• Do not jump directly to PPIs without trying the step-up approach first 1, 2
• Do not withhold treatment due to pregnancy concerns—untreated severe heartburn significantly impacts quality of life 1, 7

Pathophysiology Context

• The primary mechanism is decreased lower esophageal sphincter pressure caused by progesterone 4, 2, 3
• Mechanical factors from the gravid uterus play a smaller role 2