What to Know About Pepcid (Famotidine)

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Pepcid (famotidine) is a medication used for treating heartburn, indigestion, and gastrointestinal (GI) ulcers in children and adults. Pepcid reduces the acidity and volume of gastric (digestive) fluid in the digestive system to help alleviate symptoms of GI irritation, treat GI ulcers, and decrease the risk of ulcers in the digestive system.

The medication is available in both over-the-counter (OTC) and prescription strengths. It's generally taken in tablet form, although a liquid form is available, and it can be injected intravenously (IV, in the vein) as well.

Pepcid is used to treat acid reflux.
Paul Bradbury/Getty Images


Pepcid is approved for the treatment of several conditions that are exacerbated by gastric acid—including peptic ulcer disease (also called gastric ulcer disease), duodenal ulcers, erosive esophagitis, gastroesophageal reflux disease (GERD), and excess secretion of gastric acid or gastric fluid.

It is also used to prevent the recurrence of a duodenal ulcer that has healed. Pepcid is also indicated for treatment of the GI effects of Zollinger-Ellison Syndrome and multiple endocrine neoplasia, which are rare diseases characterized by tumors that can produce excess gastric acid.

Generally, in the early stages, these conditions might not cause noticeable effects. But they can eventually progress and cause a variety of symptoms, including:

  • Heartburn
  • Indigestion
  • Sour or bitter taste in the mouth (sour stomach)
  • Pain
  • Discomfort
  • Rarely, gastrointestinal bleeding

Your healthcare provider might perform diagnostic tests such as imaging or endoscopy to determine whether you have any of these conditions. Imaging studies provide a picture of your digestive system, which may show an ulcer or a tumor.

An endoscopy is an interventional procedure that allows your healthcare provider to view the inside of your digestive system with a flexible camera that is inserted into your mouth—this test can help identify ulcers and may show evidence of erosive esophagitis.

How It Works

Pepcid is an H2 blocker that decreases the amount of acid made in the stomach by blocking histamine-2 (H2) receptors. Histamine is a naturally occurring chemical in the body that stimulates the production of stomach acid and gastric fluid when it binds to H2 receptors.

Gastric fluid, which is acidic, contains strong chemicals that break down the food you eat. But excess gastric fluid can be irritating or caustic to the stomach, esophagus, and small intestine.

Ulcers are chronic sores that develop in any part of the body. Peptic ulcers are ulcers in the stomach, and a duodenal ulcer is an ulcer in the first portion of the small intestine. Erosive esophagitis and GERD are conditions in which the gastric fluid from the stomach irritates or damages the lower part of the esophagus.

When Pepcid blocks the H2 receptors, the result is a decrease in histamine-stimulated production of acid and gastric fluid, and this is how it relieves symptoms. Reduced gastric fluid volume and reduced acidity decreases the symptoms of heartburn and gastrointestinal irritation and helps prevent ulcers.

Off-Label Uses

This medication is used off-label for prevention of ulcers that could develop from chronic use of nonsteroidal, anti-inflammatory medications (NSAIDs). It is also used off-label for the treatment of gastritis (stomach irritation) and for prevention of stress ulcers.

COVID-19 Trial

Famotidine is under investigation in the United States in an experimental study as an add-on therapy for treating infections caused by COVID-19. Researchers are assessing the effects of hydroxychloroquine with and without famotidine on hospitalized patients who have the infection in clinical trials.

Currently, there is not a clear explanation for why adding famotidine to the medication regimen could potentially help in the treatment of COVID-19 infection.

Preliminary observations prior to clinical trials suggested that some COVID-19 patients who had already been taking famotidine might have had better than anticipated outcomes than patients who had not been taking the medication.

According to the official research protocol approved by the National Institute of Health and made publicly available on ClinicalTrials.gov, "Famotidine Injection, 10 mg/mL mixed with Normal Saline is given intravenously at 120 mg. The total daily dose proposed is 360 mg per day of famotidine IV for a maximum of 14 days, or hospital discharge, whichever comes first."

Patients are randomly selected to be in either the famotidine or no famotidine group, and the trial is double blind—which means that neither the patient nor the healthcare provider knows which patients are receiving famotidine and which are receiving placebo (inactive medication).

All patients enrolled in the trial—at least 1,200 people—receive hydroxychloroquine. Results of the trial are not yet available, so the effects of famotidine on COVID-19 infection are not yet known.

It is not considered safe to use or self-administer any form or dose of famotidine for treatment or prevention of COVID-19 infection unless you are enrolled in a clinical trial.

If this medication is proven to be safe and effective for the condition and merits FDA approval, you can discuss whether it holds any potential value for you with your healthcare provider.

Before Taking

If you have had any type of anaphylactic (allergic) reactions to any dose or formulation of famotidine or any other H2 blocker, you could be at risk of experiencing an allergic reaction when taking any formulation or dose of Pepcid.

Precautions and Contraindications

According to the manufacturer, Pepcid may pose risks for people who are pregnant and their developing babies. It can also pose risks for people who are nursing. If you use prescription or OTC Pepcid and are pregnant or planning to become pregnant, discuss the risks and benefits of staying on this medication with your healthcare provider.

There is also an increased risk of Pepcid-induced side effects for people who are elderly or who have kidney disease.

Other Drug Names

Famotidine is available in generic form in prescription strength and OTC strength. It is also available OTC as Pepcid-AC, Heartburn Relief, Acid Controller, and Acid Reducer.

Another formulation of famotidine, Duexis, contains 800 milligrams (mg) of ibuprofen and 26.6 mg of famotidine. This combination formula is prescribed for treatment of rheumatoid arthritis, and the famotidine component helps prevent GI ulcers and irritation due to the ibuprofen.


Your healthcare provider may recommend that you take OTC famotidine, or they may prescribe the prescription strength medication for you. The OTC versions generally are available in 20 mg doses and can be taken once per day or as recommended by your healthcare provider.

The prescription strength tablet formulation is available in 20 mg and 40 mg tablets, and your prescribed dose will be based on the illness being treated. In general, high doses are used short term (generally four to eight weeks) for active conditions, while lower doses may be used for a longer period of time.

The dose of famotidine for adults is:

  • Active gastric ulcer: 40 mg once per day for four to eight weeks
  • Active duodenal ulcer: 20 mg twice per day or 40 mg once per day for four to eight weeks
  • GERD: 20 mg twice per day for four to eight weeks
  • Erosive esophagitis: 20 mg twice per day or 40 mg once per day for four to eight weeks
  • Hypersecretion syndromes (including Zollinger-Ellison Syndrome and multiple endocrine neoplasia): 20 mg twice up to every six hours and can be used long term
  • Prevention of duodenal ulcer: 20 mg once per day and can be used long term

The oral tablet should not be chewed. You can take famotidine with or without food, and it is recommended that you take it between 10 minutes to an hour before consuming food that causes you to experience heartburn.

Your healthcare provider may recommend that you use an OTC formulation for treatment of intermittent symptoms such as a sour stomach or heartburn, especially if you don't have GERD or an ulcer.

Be sure to discuss the duration of your treatment with your healthcare provider and to reassess whether you still need to take the medication when you see your practitioner or when your symptoms resolve.

Intravenous Formulation

For IV administration, this medication comes as a premixed concentrated solution. It is used short term when a patient is hospitalized and can't take the oral medication.

If you normally take Pepcid, you might receive the IV formulation if you are hospitalized. Or if you are hospitalized, you might need to start taking this IV medication for the first time due to a newly diagnosed condition. Keep in mind that you will be switched to the oral version of Pepcid once you can start taking medication by mouth.

The recommended dosage for IV Pepcid in adult patients is 20 mg intravenously every 12 hours. The dose of IV famotidine used in the COVID-19 clinical trial (360 mg per day) is substantially higher than the standard dose used for treatment of GI issues.


Doses used for famotidine are adjusted for elderly adults, people who have kidney disease, and for children who weigh less than 40 kilograms ([kg] 88 pounds). Keep in mind that dosing adjustments are important for both the prescription strength and the OTC formulations.

Be sure to discuss any adjustments in OTC dosing with your healthcare provider or pharmacist. All dosages discussed are recommended by the manufacturer.

Children: Children who weigh less than 40 kg should not use the 20 mg or 40 mg tablets and should use an oral suspension instead. The recommended dose is between 0.5 to 1.0 mg of medication per kg of body weight per day.

This total dose per day is generally divided into two doses per day—one in the morning and one at bedtime. According to the manufacturer, using Pepcid for young children under the age of 1 year should only be considered along with other conservative measures such as thickened feedings.

Elderly adults: The manufacturer recommends using the lowest possible effective dose for elderly adults who do not have kidney disease. Adjustments for kidney disease need to be made for elderly adults who have kidney disease.

Kidney disease: Your healthcare provider may recommend a dosage adjustment if you have kidney disease with a low creatinine clearance. This measurement provides some insight into how quickly your body metabolizes and removes substances such as medications. A low creatinine clearance suggests that famotidine may remain in your body for a prolonged period of time.

The manufacturer recommends using approximately half the dose for people who have a creatinine clearance 30 to 60 milliliters (mL) per minute and approximately one-quarter of the dose for people who have a creatinine clearance less than 30 mL/minute.

Keep in mind that severe infections caused by COVID-19 virus can involve the kidneys.

How to Take and Store

Store Pepcid in its original container, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture. Do not allow liquid to freeze. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

Side Effects

In general, Pepcid is well tolerated. Long-term use can diminish gastric motility and decrease secretion of gastric acid, potentially causing digestive issues such as constipation.


Common side effects include:

  • Headaches
  • Dizziness
  • Constipation
  • Diarrhea

Other side effects include agitation and a susceptibility to infections such as gastroenteritis (stomach or intestinal infection) or community-acquired pneumonia.


While serious side effects of famotidine are rare when it's used as recommended, some side effects can be serious.

Watch for the following rare symptoms:

  • Hives
  • Skin rash
  • Itching
  • Wheezing
  • Swelling of face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
  • Hoarseness

If you experience any of these side effects, be sure to get medical attention promptly. These symptoms can rapidly worsen, potentially causing difficulty breathing.

Warnings and Interactions

Pepcid can decrease your body's absorption of other medications due to its impact on gastric motility and gastric acid secretion. The following medications should not be used concurrently with famotidine: cefuroxime, dasatinib, delavirdine, neratinib, pazopanib, and risedronate.

This medication is specifically noted to interact with Tizanidine, a muscle relaxant, causing effects such as low blood pressure and slow heart rate.

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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Nguyen K, Ahlawat R. Famotidine. Treasure Island, FL: StatPearls Publishing.

  3. Borrell, Brendan. New York clinical trial quietly tests heartburn remedy against coronavirus. Science.

  4. ClinicalTrials.gov Identifier: NCT04370262. A Multi-site, Randomized, Double-Blind, Multi-Arm Historical Control, Comparative Trial of the Safety and Efficacy of Hydroxychloroquine, and the Combination of HCQ and Famotidine for the Treatment of COVID-19.

  5. FDA Label. Duexis.

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