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famotidine vs ranitidine

Side-by-side comparison of famotidine and ranitidine Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

Drug Class
famotidine H2 Receptor Antagonist
ranitidine H2 Receptor Antagonist
Type
famotidine Over-the-Counter
ranitidine Over-the-Counter
Summary
famotidine

Famotidine (Pepcid) reduces stomach acid. It is used to treat ulcers, heartburn, and acid reflux.

ranitidine

Ranitidine (Zantac) helps reduce stomach acid. It can relieve heartburn and sour stomach.

What It Treats
famotidine

This medicine treats active duodenal ulcers and active gastric ulcers. It also treats heartburn (nonerosive GERD) and erosive esophagitis (damage to the esophagus from acid reflux). Famotidine can also treat conditions where the stomach makes too much acid, like Zollinger-Ellison syndrome. It can also lower the risk of duodenal ulcers coming back.

ranitidine

This medicine treats heartburn caused by acid indigestion and sour stomach. You can also take it to prevent heartburn. It can prevent heartburn caused by eating or drinking certain foods and drinks.

How It Works
famotidine

Famotidine is an H2 receptor antagonist. This means it blocks histamine, a substance that tells your stomach to make acid. By blocking histamine, famotidine reduces the amount of acid your stomach produces.

ranitidine

Ranitidine is an H2 receptor antagonist. It works by blocking histamine. Blocking histamine reduces the amount of acid your stomach makes.

Common Side Effects
famotidine
  • Headache
  • Dizziness
  • Constipation
  • Diarrhea
ranitidine
  • Headache
FAERS Reports
famotidine
  • Feeling sick to your stomach 7,259
  • Feeling tired 6,866
  • Long-term kidney problems 6,644
  • Loose, watery stools 6,448
  • The medicine is not working 6,151
ranitidine
  • Breast cancer 24,853
  • Prostate cancer 22,252
  • Colon and rectal cancer 17,674
  • Bladder cancer 16,746
  • Kidney cancer 16,278
Serious Warnings
famotidine

In elderly patients and those with kidney problems, famotidine can cause confusion, delirium, or hallucinations. If you are elderly or have kidney problems, your doctor may prescribe a lower dose. Famotidine can hide the symptoms of stomach cancer. If your symptoms don't improve, tell your doctor.

ranitidine

There are no boxed warnings in the provided data.

Pregnancy
famotidine

It is not known if famotidine will harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. Famotidine may pass into breast milk, but it's not expected to harm the baby. Talk to your doctor about breastfeeding while taking this medicine.

ranitidine

There is no information about pregnancy or breastfeeding in the provided data. Talk to your doctor if you are pregnant or breastfeeding.

Also Compare — Nearby Drugs

How to Read This famotidine vs ranitidine Comparison

famotidine is classified in the H2 Receptor Antagonist drug class, while ranitidine sits within the H2 Receptor Antagonist class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. Both drugs are available over the counter.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, famotidine has 33,368 submissions while ranitidine has 97,803. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between famotidine and ranitidine — always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.