What is famotidine for?

Famotidine is a medication that reduces stomach acid. It’s a histamine-2 (H2) blocker.

Common uses
- Treating and preventing ulcers in the stomach or small intestine (peptic ulcers)
- Treating gastroesophageal reflux disease (GERD) and esophagitis
- Relieving heartburn, sour stomach, and indigestion
- Preventing stress ulcers in hospitalized people (and sometimes preventing NSAID-related ulcers)

How it’s taken
- Available OTC in lower-dose forms (usually 10–20 mg once or twice daily for heartburn/indigestion)
- Prescription doses are higher (often 20–40 mg twice daily) for ulcers or GERD
- Can be taken with or without food
- If using antacids, follow label directions or space doses a bit apart if needed

What to know about safety and side effects
- Common: headache, dizziness, tiredness, constipation or diarrhea
- Rare but more likely in older adults: confusion or agitation
- May affect absorption of medicines that need stomach acid (e.g., some antifungals, iron supplements, calcium products); if you take other meds, ask your clinician about timing
- Kidney disease: may require dose adjustments
- Pregnancy/breastfeeding: discuss with a healthcare professional

When to seek medical help
- Severe chest pain, vomiting blood, black/tarry stools, trouble swallowing
- Allergic reactions (rash, swelling, trouble breathing)

If you tell me your age, what you’re using it for (e.g., heartburn vs. an ulcer), and whether you have kidney problems or are pregnant or breastfeeding, I can tailor the guidance or dosing ranges a bit more. Always follow your provider’s directions or the label on an OTC product.