Key takeaways
- Famotidine, available as a prescription and over-the-counter medication, reduces stomach acid to relieve heartburn and acid reflux symptoms. It’s used to treat conditions like duodenal and gastric ulcers, and gastroesophageal reflux disease.
- More common side effects of famotidine include headache, dizziness, and constipation.
- The dosage of famotidine oral tablet varies depending on the condition being treated, kidney function, and age.
The Food and Drug Administration (FDA) has approved famotidine oral tablet to:
- treat active duodenal ulcer (DU) in adults and certain children
- treat active gastric ulcer in adults and certain children
- treat symptomatic nonerosive gastroesophageal reflux disease (GERD) in adults and certain children
- treat erosive esophagitis due to GERD in adults and certain children
- treat pathological hypersecretory conditions, such as Zollinger-Ellison syndrome, in adults
- reduce the risk of DU recurrence in adults
Note: Famotidine is available as prescription as an oral tablet, oral suspension, and an injectable form. Famotidine also comes as an over-the-counter (OTC) drug. It comes as an OTC oral tablet and an OTC chewable oral tablet. This article focuses on the prescription oral tablet form of the drug.
Famotidine is a generic drug. A generic drug is a copy of the active ingredient in a brand-name medication. Pepcid AC is the over-the-counter (OTC) brand-name medication that famotidine is based on. A generic is considered to be as safe and effective as the original drug. Generics tend to cost less than brand-name drugs.
If you’re interested in treatment with Pepcid AC instead of famotidine, talk with your doctor. They can tell you whether Pepcid AC comes in forms and strengths that can be used for your condition. If you have insurance, you’ll also need to check whether your plan will cover Pepcid AC.
Learn more about how generics compare with brand-name drugs.
Famotidine is used to relieve symptoms of acid reflux and heartburn. It does this by reducing the amount of acid in your stomach. It treats the following conditions:
- Active duodenal ulcer (DU) in adults and children who weigh at least 40 kilograms (kg). The duodenal area is the part of your intestine where food passes when it leaves the stomach.
- Active gastric ulcer in adults and children who weigh at least 40 kg. Also known as stomach ulcers, these are painful sores in the stomach lining.
- Symptomatic nonerosive gastroesophageal reflux disease (GERD) in adults and children who weigh at least 40 kg. 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.
- Erosive esophagitis due to GERD in adults and children who weigh at least 40 kg. This is when stomach acid splashes up and into the lower portion of your esophagus, it can cause damage to the tissue cells in your esophagus.
- Pathological hypersecretory conditions, such as Zollinger-Ellison syndrome in adults. These are conditions where your stomach makes too much acid.
It also helps reduce the risk of DU recurrence in adults.
This drug may be used as part of a combination therapy. This means you may need to take it with other medications.
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.
Famotidine oral tablet can cause mild or serious side effects. The following list contains some of the key side effects that may occur while taking famotidine. This list does not include all possible side effects.
For more information on the possible side effects of famotidine, or tips on how to deal with a troubling side effect, talk with your doctor or pharmacist.
Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medications safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking famotidine and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.
More common side effects
The more common adult side effects for this drug are slightly different from the more common 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
- 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 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency. Serious side effects reported include:
- heart rate and rhythm problems
- severe muscle problems
- neurological problems
- liver problems
- skin problems
Allergic reactionFor some people, famotidine can cause an allergic reaction. In general, symptoms of allergic reaction can be mild or serious.
Ways to manage
For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.
For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to famotidine, your doctor may recommend taking a different medication instead.
Famotidine oral tablet can interact with several other medications. Different interactions can cause different effects. For instance, some can interfere with how well a drug works, while others can cause increased side effects.
Famotidine can reduce the absorption of other drugs, which can lead to loss of efficacy of the other drug. Famotidine also interacts with tizanidine (Zanaflex).
Before taking famotidine, be sure to tell your doctor and pharmacist about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.
If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.
Alcohol interaction
Alcohol is not known to interact with famotidine. If you drink alcohol, it’s likely safe to do so during treatment with famotidine. If you have questions about how much alcohol is safe to drink while taking famotidine, talk with your doctor or pharmacist.
The famotidine dosage your doctor prescribes will depend on several factors. These include:
- the type and severity of the condition you’re using famotidine to treat
- your age
- other medical conditions you may have
Typically, your doctor will start you on a low dosage and adjust it over time to reach the dosage that’s right for you. They’ll ultimately prescribe the smallest dosage that provides the desired effect.
The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to suit your needs.
Forms and strengths
Famotidine is available as an oral tablet. It comes in two strengths: 20 milligrams (mg) and 40 mg.
Recommended dosages
The table below provides recommended dosages for famotidine. The dosages are the same for adults and children weighing more than 40 kg. (Note that famotidine is not used in children for two of its indications: pathological hypersecretory conditions and reducing the risk of DU reoccurrence.)
| Condition | Recommended dosage | Duration of treatment |
|---|---|---|
| active DU | 40 mg once per day or 20 mg twice per day | up to 8 weeks |
| active gastric ulcer | 40 mg once per day | up to 8 weeks |
| GERD | 20 mg twice per day | up to 6 weeks |
| erosive esophagitis due to GERD | 20 mg twice per day or 40 mg twice per day | up to 12 weeks |
| pathological hypersecretory conditions | 20 mg every 6 hours with a maximum dose of 160 mg every 6 hours | per your doctor’s recommendation |
| reduce the risk of DU reoccurrence | 20 mg once per day | one year or per your doctor’s recommendation |
Special considerations
For 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 48 hours instead of every day.
About taking famotidine
The following information focuses on key dosage issues.
- When to take: You should take famotidine once per day before bedtime or twice per day in the morning and before bedtime. Taking the medication around the same time of day helps keep a steady level of the drug in your body. This helps famotidine work effectively.
- If you miss a dose: If you miss a dose, take your dose as soon as you remember. But if it is close to time for your next dose, skip the missed dose. You don’t want to double up on doses because that increases your risk for side effects.
- Taking famotidine with food: You can take famotidine with or without food.
Overdose
Do not use more famotidine than your doctor recommends. For some drugs, doing so may lead to unwanted side effects or overdose.
What to do in case you take too much famotidine
If you think you’ve taken too much of this drug, call your doctor. You can also call America’s Poison Centers at 800-222-1222 or use its online tool. However, if your symptoms are severe, call 911 or your local emergency number or go to the nearest emergency room right away.
Before taking famotidine, discuss your health history with your doctor. Famotidine may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:
- kidney problems
- previous allergic reaction to this or a similar drug
- pregnancy
- breastfeeding
Note: For more information about the potential negative effects of famotidine, see the “Famotidine side effects” section.
As with all medications, the cost of famotidine can vary. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.
Financial and insurance assistance: If you need financial support to pay for famotidine, or if you need help understanding your insurance coverage, help is available.
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.
Disclaimer: Medical News Today 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.