Famotidine | Side Effects, Dosage, Uses & More
Advertisement

Generic Name:

famotidine, Oral tablet

Generic Name:
Pepcid,Pepcid AC,Pepcid AC Maximum Strength

famotidine, Oral tablet

All Brands

  • Pepcid
  • Pepcid AC
  • Pepcid AC Maximum Strength
SECTION 1 of 5

Highlights for famotidine

Oral tablet
1

Famotidine is used to relieve symptoms of acid reflux and heartburn. It does this by reducing the amount of acid in your stomach.

2

This drug comes in the form of a tablet and a liquid suspension you take by mouth. It also comes in an injectable form, which is only given by a healthcare provider.

3

Famotidine is available as a brand-name drug called Pepcid. It’s also available as a generic drug.

4

The more common side effects of this drug include headache, dizziness, constipation, and diarrhea.

5

If you have kidney disease, you may need to take a smaller dose of famotidine. A smaller dose will help you avoid serious side effects, such as confusion and an irregular heart rhythm called QT prolongation.

What is famotidine?

Famotidine is a prescription and over-the-counter drug. Prescription famotidine is available as an oral tablet and an oral suspension. It also comes in an injectable form, which is only given by a healthcare provider.

Famotidine is available as a generic drug. Generic drugs usually cost less. In some cases, they may not be available in every strength or form as the brand-name version.

This drug may be used as part of a combination therapy. This means you may need to take it with other medications.

Why it's used

Famotidine is used to relieve symptoms of acid reflux and heartburn. It does this by reducing the amount of acid in your stomach.

More Details

How it works

Famotidine belongs to a class of drugs called histamine-2 receptor blockers. A class of drugs is a group of medications that work in a similar way.

More Details

Why it's used

Famotidine is used to relieve symptoms of acid reflux and heartburn. It does this by reducing the amount of acid in your stomach.

This drug is used to treat the following conditions:

  • gastroesophageal reflux disease (GERD). GERD happens when acid in your stomach backs up into your esophagus (the tube that connects your mouth to your stomach). This may cause a burning feeling in your chest or throat, a sour taste in your mouth, or burping.
  • acid-related damage to the lining of your esophagus
  • duodenal ulcers. The duodenal area is the part of your intestine where food passes when it leaves the stomach.
  • stomach ulcers
  • conditions where your stomach makes too much acid. These conditions include Zollinger-Ellison syndrome.

How it works

Famotidine belongs to a class of drugs called histamine-2 receptor blockers. A class of drugs is a group of medications that work in a similar way. These drugs are often used to treat similar conditions.

Famotidine works by blocking the histamine 2 (H2) receptor in your stomach. This receptor helps release acid in your stomach. By blocking this receptor, this drug lowers the amount of acid released in your stomach.

Advertisement
SECTION 2 of 5

famotidine Side Effects

Oral tablet

More common side effects

The adult side effects for this drug are slightly different from the side effects for children.

  • Adult side effects can include:

    • headache
    • dizziness
    • constipation
    • diarrhea
  • Children under one year of age may also experience:

    • agitation, unusual restlessness, or crying for no clear reason

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious side effects

Call your doctor right away if you have serious side effects. Call 9-1-1 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects and their symptoms can include the following:

  • Heart rate and rhythm problems. Symptoms can include:

    • dizziness
    • fainting
    • shortness of breath
    • irregular heart rate and rhythm
  • Severe muscle problems. Symptoms can include:

    • unusual muscle pain that you cannot explain
    • weakness
    • fever
  • Neurological problems. Symptoms can include:

    • agitation
    • anxiety
    • depression
    • trouble sleeping
    • seizures
    • sexual problems, such as decreased sex drive
  • Liver problems. Symptoms can include:

    • unexplained or unusual weakness
    • decrease in appetite
    • pain in your abdomen (stomach area)
    • change in the color of your urine
    • yellowing of your skin or the whites of your eyes
  • Skin problems. Symptoms can include:

    • blisters
    • rash
    • mouth sores or ulcers
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Famotidine doesn’t cause drowsiness.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
SECTION 3 of 5

famotidine May Interact with Other Medications

Oral tablet

An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well. To help prevent interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking.

To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Famotidine warnings
kidney disease warning
People with moderate or severe kidney disease

If you have kidney problems, you may not be able to clear this drug from your body. This may increase the levels of this drug in your body. The increased levels may cause more side effects, such as confusion and an irregular heart rhythm called QT prolongation.

pregnancy warning
Pregnant women

Famotidine is a category B pregnancy drug. That means two things:

  1. Research in animals has not shown a risk to the fetus when the mother takes the drug.
  2. There aren’t enough studies done in humans to show if the drug poses a risk to the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. Animal studies do not always predict the way humans would respond. Therefore, this drug should only be used in pregnancy if clearly needed.

breast feeding warning
Women who are breast-feeding

Famotidine may pass into breast milk and may cause side effects in a child who is breastfed.

Talk to your doctor if you breastfeed your child. You may need to decide whether to stop breastfeeding or stop taking this medication.

senior warning
For seniors

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

childrens warning
For children
  • Famotidine can be used in children of all ages for the treatment of gastroesophageal reflux disease (GERD).
  • This drug hasn’t been studied in children under 1 year of age for the treatment of ulcers.
  • This drug hasn’t been studied in children under 16 years of age for the treatment of pathological hypersecretory conditions.
call the doctor
When to call the doctor

Call your doctor right away if you become pregnant while taking this drug.

Call your doctor if your acid reflux, heartburn, or ulcer symptoms aren’t getting better even though you’re taking this drug. It may take up to 4 weeks for your symptoms to improve.

allergy warning
Allergies

Famotidine can cause a severe allergic reaction. Symptoms can include:

  • trouble breathing
  • swelling in your eye(s) or face
  • swelling of your throat or tongue
  • rash
  • hives

If you have an allergic reaction, call your doctor or local poison control center right away. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it or other histamine receptor blockers (such as cimetidine, ranitidine, or nizatidine). Taking it again could be fatal (cause death).

SECTION 4 of 5

How to Take famotidine (Dosage)

Oral tablet

All possible dosages and drug forms may not be included here. Your dosage, drug form, and how often you take the drug will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Duodenal ulcer

Brand: Pepcid

Form: Oral tablet
Strengths: 20 mg, 40 mg
Form: Oral suspension
Strengths: 40 mg/5 mL

Generic: famotidine

Form: Oral tablet
Strengths: 20 mg, 40 mg
Form: Oral suspension
Strengths: 40 mg/5 mL
Adult dosage (ages 18 years and older)
  • Short-term dose: 40 mg taken once per day at bedtime for up to 4 weeks. Your doctor may divide your dose into 20 mg taken two times per day.
  • Long-term dose: 20 mg taken once per day at bedtime. 
Child dosage (age 17 years)
  • Short-term dose: 40 mg taken once per day at bedtime for up to 4 weeks. Your doctor may divide your dose into 20 mg taken two times per day.
  • Long-term dose: 20 mg taken once per day at bedtime. 
Child dosage (ages 1–16 years)
  • Dose: 0.5 mg/kg of body weight per day, up to 40 mg per day. You’ll take either one dose at bedtime or 2 equally divided doses per day.
  • Dose changes: Your doctor may increase your dose and length of treatment based on how well you respond to the drug. They may increase your dose up to 1 mg/kg per day.
Child dosage (under 1 year of age)

This drug hasn’t been studied in children under 1 year of age for the treatment of this condition.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dose or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Special considerations

People with moderate or severe kidney disease: Your doctor may decrease your dose of this drug by half. Or they may have you take one dose every 36–48 hours instead of every day.

Warnings

You can take this drug with antacids if needed.

Gastric ulcer

Brand: Pepcid

Form: Oral tablet
Strengths: 20 mg, 40 mg
Form: Oral suspension
Strengths: 40 mg/5 mL

Generic: famotidine

Form: Oral tablet
Strengths: 20 mg, 40 mg
Form: Oral suspension
Strengths: 40 mg/5 mL
Adult dosage (ages 18 years and older)

Short-term dose: 40 mg taken once per day at bedtime.

Child dosage (age 17 years)
  • Short-term dose: 40 mg taken once per day at bedtime for up to 4 weeks. Your doctor may divide your dose into 20 mg taken two times per day.
  • Long-term dose: 20 mg taken once per day at bedtime.
Child dosage (ages 1–16 years)
  • Dose: 0.5 mg/kg of body weight per day, up to 40 mg per day. You’ll take either one dose at bedtime or 2 equally divided doses per day.
  • Dose changes: Your doctor may increase your dose and length of treatment based on how well you respond to the drug. They may increase your dose up to 1 mg/kg per day.
Child dosage (under 1 year of age)

This drug hasn’t been studied in children under 1 year of age for the treatment of this condition.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dose or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Special considerations

People with moderate or severe kidney disease: Your doctor may decrease your dose of this drug by half. Or they may have you take one dose every 36–48 hours instead of every day.

Warnings

You can take this drug with antacids if needed.

Gastroesophageal reflux disease (GERD)

Brand: Pepcid

Form: Oral tablet
Strengths: 20 mg, 40 mg
Form: Oral suspension
Strengths: 40 mg/5 mL

Generic: famotidine

Form: Oral tablet
Strengths: 20 mg, 40 mg
Form: Oral suspension
Strengths: 40 mg/5 mL
Adult dosage (ages 18 years and older)
  • Gastroesophageal reflux disease (GERD) symptoms: 20 mg taken two times per day for up to 6 weeks.
  • Esophagitis (irritated esophagus with sores) with GERD symptoms: 20–40 mg taken two times per day for up to 12 weeks.
Child dosage (age 17 years)
  • Gastroesophageal reflux disease (GERD) symptoms: 20 mg taken two times per day for up to 6 weeks.
  • Esophagitis (irritated esophagus with sores) with GERD symptoms: 20–40 mg taken two times per day for up to 12 weeks.
Child dosage (age 1–16 years)
  • Dose: 1 mg/kg of body weight per day. You’ll take this as one dose or in 2 equally divided doses per day, up to 40 mg taken twice per day.
  • Dose changes: Your doctor may increase your dose and length of treatment based on how well you respond to the drug. They may increase your dose up to 2 mg/kg per day.
Child dosage (ages 3 months to 1 year)

Dose: 0.5 mg/kg of body weight given twice per day for up to 8 weeks

Child dosage (ages 0–3 months)

Dose: 0.5 mg/kg of body weight given once per day for up to 8 weeks

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dose or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Special considerations

People with moderate or severe kidney disease: Your doctor may decrease your dose of this drug by half. Or they may have you take one dose every 36–48 hours instead of every day.

Warnings

You can take this drug with antacids if needed.

Pathological hypersecretory conditions

Brand: Pepcid

Form: Oral tablet
Strengths: 20 mg, 40 mg
Form: Oral suspension
Strengths: 40 mg/5 mL

Generic: famotidine

Form: Oral tablet
Strengths: 20 mg, 40 mg
Form: Oral suspension
Strengths: 40 mg/5 mL
Adult dosage (ages 18 years and older)
  • Typical starting dose: 20 mg taken every 6 hours.
  • Dose increases: Your doctor may increase your dose based on your symptoms.
  • Maximum dose: People with severe disease may need 160 mg taken every 6 hours.
Child dosage (ages 16–17 years)
  • Typical starting dose: 20 mg taken every 6 hours.
  • Dose increases: Your doctor may increase your dose based on your symptoms.
  • Maximum dose: People with severe disease may need 160 mg taken every 6 hours.
Child dosage (under 0–15 years)

This drug hasn’t been studied in children under 16 years of age for the treatment of this condition.

Senior dosage (ages 65 years and older)

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

Your doctor may start you on a lowered dose or a different dosing schedule. This can help keep levels of this drug from building up too much in your body.

Special considerations

People with moderate or severe kidney disease: Your doctor may decrease your dose of this drug by half. Or they may have you take one dose every 36–48 hours instead of every day.

Warnings

You can take this drug with antacids if needed.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Famotidine comes with serious risks if you don’t take it as prescribed.

If you stop taking the drug suddenly or don’t take it at all

Your acid reflux, heartburn, or ulcer symptoms may not get better or may get worse.

If you miss doses or don’t take the drug on schedule

Your medication may not work as well or may stop working completely. For this drug to work well, a certain amount needs to be in your body at all times.

If you take too much

You could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include:

  • agitation
  • confusion
  • seizures
  • severe muscle pain

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room right away.

What to do if you miss a dose

Take your dose as soon as you remember. But if you remember just a few hours before your next scheduled dose, take only one dose. Never try to catch up by taking two doses at once. This could result in dangerous side effects.

How to tell if the drug is working

You should have less pain and your symptoms should improve.

Famotidine is used for long-term treatment of Zollinger-Ellison syndrome and maintaining healing of ulcers.


Famotidine is used for short-term treatment of gastroesophageal reflux disease (GERD) and duodenal and gastric ulcers.

Important considerations for taking famotidine
take famotidine with or without food
You can take famotidine with or without food
timing
Take this drug at the time(s) recommended by your doctor
can cut or crush the tablet
You can cut or crush the tablet
storage
Store this drug carefully
See Details
medication is refillable
A prescription for this medication is refillable
See Details
Travel
Travel
See Details
diet
Your diet
See Details
not usually stocked
Not every pharmacy stocks this drug. When filling your prescription, be sure to call ahead
prior authorization
Insurance
See Details

Store this drug carefully

  • Store the oral tablets at 77°F (25°C). They may be stored for a short time from 59°F to 86°F (15°C to 30°C). Keep them away from light.
  • Store the oral suspension at 77°F (25°C). You may store it briefly from 59°F to 86°F (15°C to 30°C). Protect it from freezing. Throw away unused oral suspension after 30 days. 
  • Don’t store this medication in moist or damp areas, such as bathrooms.

A prescription for this medication is refillable

You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you. When flying, never put it into a checked bag. Keep it in your carry-on bag.
  • Don’t worry about airport x-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Your diet

Certain foods and beverages may irritate your stomach. This irritation could make your symptoms worse. Your doctor may suggest that you avoid spicy, acidic, and fatty foods while you take this drug. (Acidic foods include tomatoes and citrus fruits.) They may also ask you to avoid beverages with caffeine. 

Insurance

Many insurance companies require a prior authorization for this drug. This means your doctor will need to get approval from your insurance company before your insurance company will pay for the prescription.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be better suited for you than others. Talk to your doctor about other drug options that may work for you.

SECTION 5 of 5

How Much Does famotidine Cost?

Oral tablet

We've partnered with GoodRx so you can compare prices, find discounts and save up to 80% on your next prescription. Check out the low coupon prices below — no insurance required.

Compare prices and save up to 80% on your next refill!

Lowest price for famotidine

Walmart $4.00
Kmart $5.00
Sams Club $6.68
These prices represent the lowest priced national pharmacies for famotidine on GoodRx. They may be lower than your insurance.

Enter your zip code to find the best deal near you.

These prices represent the lowest priced national pharmacies for famotidine on GoodRx. They may be lower than your insurance.

Show Sources

Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on January 13, 2016

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
Advertisement
Advertisement
Advertisement