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Pepcid AC Chewable Tablets Side Effects

Generic Name: famotidine

Note: This document contains side effect information about famotidine. Some of the dosage forms listed on this page may not apply to the brand name Pepcid AC Chewable Tablets.

For the Consumer

Applies to famotidine: oral powder for suspension, oral tablet, oral tablet chewable, oral tablet disintegrating

Along with its needed effects, famotidine (the active ingredient contained in Pepcid AC Chewable Tablets) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking famotidine:


  • Bleeding gums
  • blistering, peeling, or loosening of the skin
  • blood in the urine or stools
  • bloody, black, or tarry stools
  • chest pain
  • chills
  • cough or hoarseness
  • diarrhea
  • fever
  • fever with or without chills
  • general feeling of tiredness or weakness
  • high fever
  • itching
  • joint or muscle pain
  • lower back or side pain
  • painful or difficult urination
  • pale skin
  • pinpoint red spots on the skin
  • red, irritated eyes
  • red skin lesions, often with a purple center
  • shortness of breath
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • swollen glands
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Incidence Not Known

  • Abdominal or stomach pain
  • anxiety
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • clay-colored stools
  • dark urine
  • depression
  • difficulty with breathing
  • difficulty with swallowing
  • dizziness
  • dry mouth
  • fainting
  • false sense of well-being
  • fast, irregular, pounding, or racing heartbeat or pulse
  • headache
  • hives
  • hyperventilation
  • irritability
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • loss of appetite
  • loss of bladder control
  • loss of consciousness
  • mood swings
  • nausea
  • nervousness
  • noisy breathing
  • personality changes
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rash
  • restlessness
  • seizures
  • shaking
  • skin rash
  • swelling around the eyes
  • tightness in the chest
  • total body jerking
  • trouble with sleeping
  • troubled with breathing
  • unpleasant breath odor
  • vision changes
  • vomiting of blood
  • wheezing
  • yellow eyes or skin

Some side effects of famotidine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less Common

  • Difficulty having a bowel movement (stool)


  • Swelling of the breasts or breast soreness in both females and males

Incidence Not Known

  • Abdominal or stomach discomfort
  • blemishes on the skin
  • change in taste or bad, unusual or unpleasant (after) taste
  • continuing ringing or buzzing or other unexplained noise in the ears
  • decreased interest in sexual intercourse
  • difficulty with moving
  • dry skin
  • fear
  • hair loss or thinning of the hair
  • hearing loss
  • hives or welts
  • inability to have or keep an erection
  • loss in sexual ability, desire, drive, or performance
  • mood or mental changes
  • muscle cramps
  • muscle stiffness
  • pimples
  • redness of the skin
  • redness of the white part of the eyes
  • seeing, hearing, or feeling things that are not there
  • sleeplessness
  • unable to sleep
  • weight loss

For Healthcare Professionals

Applies to famotidine: compounding powder, intravenous solution, oral powder for reconstitution, oral tablet, oral tablet chewable, oral tablet disintegrating


The most commonly reported side effects include headache, dizziness, constipation, and diarrhea.[Ref]


Common (1% to 10%): Constipation, diarrhea

Uncommon (0.1% to 1%): Nausea, vomiting, flatulence, dry mouth, abdominal discomfort or distension[Ref]

Nervous system

Convulsions occurred in patients with renal dysfunction.[Ref]

Common (1% to 10%): Headache, dizziness

Very rare (less than 0.01%): Paresthesia, somnolence, epileptic seizures, convulsion

Frequency not reported: Grand mal seizure, taste disorder[Ref]


Uncommon (0.1% to 1%): Rash, pruritus

Rare (0.01% to 0.1%): Urticaria, angioneurotic edema

Very rare (less than 0.01%): Alopecia, severe skin reactions, toxic epidermal necrolysis, Stevens-Johnson syndrome, epidermal necrolysis

Frequency not reported: Acne, dry skin, flushing[Ref]


Uncommon (0.1% to 1%): Fatigue

Frequency not reported: Asthenia, fatigue, facial/orbital edema, tinnitus[Ref]


Uncommon (0.1% to 1%): Loss of appetite

Frequency not reported: Anorexia[Ref]


Rare (0.01% to 0.1%): Thrombocytopenia, leukopenia, agranulocytosis, pancytopenia

Frequency not reported: Neutropenia[Ref]


Rare (0.01% to 0.1%): Intrahepatic cholestasis, jaundice, increased liver enzyme abnormalities (transaminases, gamma GT, alkaline phosphatase, bilirubin)

Frequency not reported: Cholestatic jaundice, hepatitis[Ref]


Rare (0.01% to 0.1%): Hypersensitivity reactions, anaphylaxis[Ref]


Rare (0.01% to 0.1%): Bronchospasm

Frequency not reported: Interstitial pneumonia[Ref]


Rare (0.01% to 0.1%): Arthralgia

Very rare (less than 0.01%): Muscle cramps

Frequency not reported: Rhabdomyolysis, musculoskeletal pain[Ref]


When patients obtained follow-up, psychic disturbances were found to be reversible.[Ref]

Very rare (less than 0.01%): Hallucinations, disorientation, confusion, anxiety, agitation, depression, reduced libido, insomnia

Frequency not reported: Psychic disturbances[Ref]


QT interval prolongation occurred in patients with renal dysfunction.[Ref]

Very rare (less than 0.01%): Chest tightness, prolonged QT interval

Frequency not reported: Arrhythmia, atrioventricular block, palpitation[Ref]


Very rare (less than 0.01%): Impotence[Ref]


Frequency not reported: Conjunctival injection[Ref]


Frequency not reported: Gynecomastia[Ref]


1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

2. "Product Information. Pepcid (famotidine)." Merck & Co, Inc, West Point, PA.

3. "Product Information. Pepcid AC (famotidine)." Johnson and Johnson/Merck, Fort Washington, PA.

4. Cerner Multum, Inc. "Australian Product Information." O 0

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.