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Common Brand Name(s): Pepcid AC
This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Famotidine is known as an H2 blocker. It works by reducing the amount of acid in your stomach. It is used to prevent and treat heartburn and other symptoms caused by too much acid in the stomach (acid indigestion).
Check the ingredients on the label even if you have used the product before. The manufacturer may have changed the ingredients. Also, products with similar names may contain different ingredients meant for different purposes. Taking the wrong product could harm you.
To treat heartburn and acid indigestion, take 1 tablet or capsule with a glass of water as needed, unless otherwise directed by your doctor. Swallow the tablets and capsules whole without chewing. If you are using the chewable tablets, chew completely and swallow one tablet as needed. Do not swallow whole. Famotidine can be taken with or without food.
To prevent heartburn and acid indigestion, take famotidine 15-60 minutes before eating food or drinking beverages that can cause indigestion.
Do not take more than 2 tablets in 24 hours unless directed by your doctor. Follow all directions on the product package. If you have any questions, ask your doctor or pharmacist.
Stop taking this medication and call your doctor promptly if your symptoms continue after you begin taking it, or if they do not improve after you have been taking this medication for 14 days in a row. Do not take this medication for more than 14 days in a row without talking with your doctor.
Headache, constipation or diarrhea may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
If your doctor has directed you to use this medication, remember that your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if you have any serious side effects, including:
Get medical help right away if you have any very serious side effects, including:
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before taking famotidine, tell your doctor or pharmacist if you are allergic to it; or to other H2 blockers (such as cimetidine, ranitidine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
If you have any of the following health problems, consult your doctor or pharmacist before using this medication:
Some symptoms may actually be signs of a more serious condition. Get medical help right away if you have:
In addition, before you self-treat with this medication, get medical help right away if you have any of these signs of a serious condition:
This chewable form of this medication contains aspartame. If you have phenylketonuria (PKU) or any other condition that requires you to restrict your intake of aspartame (or phenylalanine), consult your doctor or pharmacist regarding the safe use of this medication.
Do not use this medication in children younger than 12 unless directed by the doctor.
Older adults may be more sensitive to the side effects of this drug, especially mental/mood changes (such as confusion), seizure, or unusual tiredness.
During pregnancy, this medication should only be used if clearly needed. Discuss the risks and benefits with your doctor. Tell your doctor if you are pregnant before using this medication.
This drug passes into breast milk. Consult your doctor before breast-feeding.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products need stomach acid so that the body can absorb them properly. Famotidine decreases stomach acid, so it may change how well these products work. Some affected products include atazanavir, dasatinib, certain azole antifungals (such as itraconazole, ketoconazole), levoketoconazole, pazopanib, among others.
Do not take this medication with other products that contain famotidine or other H2 blockers (cimetidine, nizatidine, ranitidine).
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Alberta residents can call PADIS (Poison and Drug Information Service) 24 hours a day at 1-800-332-1414. Canada residents can call a provincial poison control center.
Lifestyle changes such as stress reduction programs, stopping smoking, limiting alcohol, and diet changes (such as avoiding caffeine and certain spices) may help this medication work better. Talk to your doctor or pharmacist about lifestyle changes that might benefit you.
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised September 2022.
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