Famotidine: Uses, How to Take, Dosing & Side Effects

Updated in December 2023

Famotidine is a medication that is indicated for the treatment of stomach ulcers or ulcers in the upper intestines. It can also help to reduce the production of stomach acid in cases of GERD, gastritis or Zollinger-Ellison syndrome.

This medication can be purchased in pill form at the pharmacy with a prescription in doses of 20 mg or 40 mg. 

Famotidine should solely be used in the doses and for the duration prescribed by your doctor.

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Common uses

Famotidine is indicated for the treatment of:

  • Benign stomach or intestinal ulcers
  • Gastroesophageal reflux disease (GERD)
  • Gastritis
  • Zollinger-Ellison syndrome

This medications works by reducing the production of stomach acid in the stomach. It attaches to stomach wall cells to block the action of histamine, which activates the stomach acid production. 

Famotidine should only be used as prescribed by a doctor, and can also be prescribed to prevent gastric ulcers or duodenal ulcers. 

How to take

Famotidine is prescribed in pill form, in doses of 20 mg or 40 mg. It should be taken orally with a cup of water before or after meals at the times indicated by your doctor. 

Famotidine dosing varies depending on the condition being treated: 

Indications Dosing (for adults)
Treatment for benign ulcer in the stomach or intestine  The recommended dose is one 40 mg pill per day before bed, for 4 to 8 weeks. 
Preventing stomach or intestinal ulcers, or maintenance treatment  The recommended dose is one 20 mg pill per day, before bed.
Zollinger-Ellison syndrome The initial dose is one 20 mg pill every 6 hours. Dosing can be increased to uip to 800 mg per day, depending on the severity of symptoms and response to treatment. 

Patients with kidney failure should be prescribed reduced doses, as per the doctor. 

To complement treatment, you can also utilize these home remedies for gastritis

Possible side effects

Side effects associated with famotidine use may include headache, dizziness, diarrhea, constipation, dry mouth, nausea, vomiting, abdominal bloating, loss of appetite or fatigue. breastmilk production (without pregnancy), enlarged liver and yellow skin. 

Famotidine can also cause serious side effects that should be immediately communicated to the doctor, like muscle pain, weakness, excessive fatigue, dark urine color, hallucinations, agitation, confusion, seizures, increased heart rate, and sudden dizziness that feels like fainting. 

Although it is more rare, famotidine can cause serious allergic reactions that require immediate medical attention. If you experience symptoms like shortness of breath, the feeling you throat is closing, or a swollen mouth, tongue or face,  you should proceed to the closest emergency room. 

Contraindications for use

Famotidine should not be used by children, pregnant women or breastfeeding women, nor by people who have stomach cancer. 

In addition, this medication should not be used by people who have any allergies to any components in the medication's formula, to yellow tartrazine, or to acetylsalicylic acid. 

Famotidine use in anyone with liver or kidney problems should be closely monitored by a doctor.

Famotidine can reduce the absoprtion or other medications (like cefpodoxime, domperidone, itraconozol, ketoconazole or melphalan) due to the reduced levels of stomach acid, which is why you should communicate all medications you are taking to your doctor.