Ranitidine Use in Pregnancy: Important Context
Ranitidine has been withdrawn from the market worldwide since 2020 due to contamination with N-nitrosodimethylamine (NDMA), a probable carcinogen, and is no longer available for prescription or use in pregnancy. However, if this question pertains to historical dosing or academic purposes, the evidence-based dosing during pregnancy was ranitidine 150 mg twice daily.
Historical Dosing for Pregnant Women
The most robust evidence supports ranitidine 150 mg orally twice daily for treatment of gastroesophageal reflux symptoms during pregnancy 1.
Evidence-Based Dosing Regimen
Ranitidine 150 mg twice daily was the only regimen proven effective in a double-blind, placebo-controlled trial specifically conducted in pregnant women with heartburn refractory to conservative measures 1.
This twice-daily dosing achieved a 55.6% reduction in heartburn severity compared to baseline and a 44.2% reduction compared to placebo in pregnant patients 1.
Once-daily dosing (150 mg at bedtime) was NOT effective in the pregnancy trial, showing no significant improvement over placebo 1.
Safety Profile in Pregnancy
Ranitidine had a long safety record in pregnancy with no evidence of teratogenicity in humans, though it was recommended to avoid all medications in the first trimester when possible 2.
The drug was often chosen by clinicians when H2-blocker therapy was necessary during pregnancy due to its established safety profile 2.
No dose-related toxicity was observed across an eightfold range of therapeutic doses (75-1200 mg daily) in general populations, with adverse events occurring in 20% of ranitidine users versus 27% of placebo users 3.
Clinical Context and Alternatives
H2-blockers like ranitidine were mentioned as adjunctive therapy for gastrointestinal protection, though this was in the context of NSAID use rather than primary GERD treatment 2.
The standard non-pregnancy dose for gastric conditions was 300 mg at bedtime or 150 mg twice daily 4.
Current Clinical Practice
Given ranitidine's market withdrawal, pregnant women with GERD should be treated with alternative H2-receptor antagonists or proton pump inhibitors that remain available and have established safety profiles in pregnancy. Consult current guidelines for appropriate alternatives, as the medication landscape has changed significantly since 2020.