Famotidine: what it does and when to use it

Got heartburn, acid reflux, or a peptic ulcer? Famotidine (brand name Pepcid) is an H2 blocker that lowers stomach acid. It can ease heartburn, help heal ulcers, and reduce overnight acid production. People use it as a short-term fix for symptoms or as part of longer treatment when a doctor prescribes it.

How famotidine works and common uses

Famotidine blocks histamine receptors (H2) in the stomach that signal acid production. That means less acid to irritate your esophagus and stomach lining. Typical uses include:

• Occasional heartburn and indigestion relief
• Gastroesophageal reflux disease (GERD) symptom control
• Treatment and prevention of stomach and duodenal ulcers
• Short-term hospital use for stress ulcer prevention or high acid conditions

Onset is usually within 30–60 minutes and effects can last about 8–12 hours. It's not as fast as an antacid for immediate pain, but it lasts longer.

Dosage, safety, and common side effects

OTC strengths are commonly 10 mg or 20 mg. For occasional heartburn follow the label—often one dose at symptom start or a recommended schedule. Prescription doses vary: common Rx dosing for ulcers or more severe reflux can be 20–40 mg once or twice daily. People with kidney problems need lower doses—check with a doctor.

Common side effects are mild: headache, dizziness, constipation, or diarrhea. Serious reactions are rare but include allergic responses and confusion in older adults. If you notice sudden swelling, trouble breathing, or severe skin rash, seek immediate care.

Two practical tips: if you need relief at night, take famotidine before bedtime; if your symptoms happen after meals, taking it an hour before a large meal can help. If you need rescue relief right away, an antacid works faster than famotidine.

If heartburn occurs more than twice a week, or you have weight loss, difficulty swallowing, vomiting blood, or black stools, contact a healthcare provider — those signs need evaluation.

Drug interactions are limited compared with older H2 blockers, but lowering stomach acid can reduce absorption of some medicines that need an acidic environment (for example, certain antifungals or HIV meds). Always tell your clinician about all drugs and supplements you take.

Short answer: famotidine is a useful, generally safe option for many people with acid-related symptoms. Use the labeled dose for occasional symptoms and see a clinician if you need it regularly or have worrying signs. Your doctor can advise on dose adjustments, testing for ulcers or reflux, and whether a different treatment (like a PPI) is better for you.