Pepcid AC Side Effects
Generic Name: famotidine
Note: This page contains side effects data for the generic drug famotidine. It is possible that some of the dosage forms included below may not apply to the brand name Pepcid AC.
It is possible that some side effects of Pepcid AC may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.
For the Consumer
Applies to famotidine: oral powder for suspension, oral tablet, oral tablet chewable, oral tablet disintegrating
As well as its needed effects, famotidine (the active ingredient contained in Pepcid AC) may cause unwanted side effects that require medical attention.
If any of the following side effects occur while taking famotidine, check with your doctor immediately:Rare
- Bleeding gums
- blistering, peeling, or loosening of the skin
- blood in the urine or stools
- bloody, black, or tarry stools
- chest pain
- cough or hoarseness
- fever with or without chills
- general feeling of tiredness or weakness
- high fever
- 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
- Abdominal or stomach pain
- burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
- clay-colored stools
- dark urine
- difficulty with breathing
- difficulty with swallowing
- dry mouth
- false sense of well-being
- fast, irregular, pounding, or racing heartbeat or pulse
- 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
- noisy breathing
- personality changes
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
- 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
- yellow eyes or skin
Some famotidine side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:Less common
- Difficulty having a bowel movement (stool)
- Swelling of the breasts or breast soreness in both females and males
- 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
- 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
- redness of the skin
- redness of the white part of the eyes
- seeing, hearing, or feeling things that are not there
- 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
Gastrointestinal side effects including diarrhea (1.7%) and constipation (1.2%) have been reported. Vomiting, nausea, abdominal discomfort, anorexia, and dry mouth have been reported infrequently. Hypergastrinemia of uncertain clinical significance has also been reported.
Nervous system side effects have included headache (1% to 4.7%) and dizziness (1.3%). Grand mal seizures, paresthesia, and somnolence have been reported infrequently. Lethargy, confusion, psychosis, and agitation have been reported. Delirium has been reported, which reversed upon drug withdrawal. Convulsions, in patients with impaired renal function, have been reported very rarely.
Confusion, lethargy, delirium, psychosis, agitation, seizures and somnolence have been reported, particularly in elderly patients and patients with multiple medical problems. The frequency of such reactions may be greater than previously believed. The FDA has accumulated 72 reported cases of such central nervous system reactions. All H2-blockers cross the blood-brain barrier and are found in the cerebrospinal fluid.
Hepatic side effects have included mild elevations of liver function tests. The clinical significance of these elevations is unknown. Jaundice and cholestatic jaundice have been reported infrequently. Cases of drug-induced hepatitis have also been reported.
Cardiovascular side effects have included decreases in stroke volume and cardiac output and may be clinically significant in patients with preexisting cardiac dysfunction. A variety of arrhythmias, including bradycardia, tachycardia, AV conduction defects (including AV block), and palpitations have also been reported rarely. Prolonged QT interval has been reported very rarely in patients with impaired renal function whose dose/dosing interval of famotidine (the active ingredient contained in Pepcid AC) may not have been adjusted appropriately.
A 92-year-old male with a history of diabetes mellitus, hypertension, coronary artery disease, and pacemaker implantation for sick sinus syndrome experienced acquired long QT syndrome coincident with famotidine therapy. The patient was admitted with fever, periurethral abscess, and enterococcal sepsis. He was treated with several medications including famotidine. He was administered famotidine at 20 mg per nasogastric tube twice a day after admission. He developed an acute myocardial infarction 10 hours after famotidine therapy. The admission 12-lead electrocardiogram revealed a ventricular paced rhythm at a rate of 60 beats/min and a QTc of 439 ms. After two 20 mg doses of famotidine, the QTc became markedly prolonged at 618 ms. Four days after famotidine was discontinued, the QTc returned close to baseline at 445 ms.
Hypersensitivity side effects have infrequently included anaphylaxis, angioedema, orbital or facial edema, urticaria, rash, conjunctival infection, toxic epidermal necrolysis (very rare), erythema multiforme, and Stevens-Johnson syndrome (very rare).
Renal side effects have included rare cases of interstitial nephritis.
Endocrine side effects have included anti-androgen effects of reversible hyperprolactinemia and gynecomastia.
Dermatologic side effects have infrequently included alopecia, acne, pruritus, dry skin, and flushing. At least one case of contact dermatitis in a worker handling famotidine (the active ingredient contained in Pepcid AC) has been reported.
A 22-year-old man reported painful, erythematous macules on his chest five days after starting famotidine. These progressed to hemorrhagic, painful erosions of the oral, conjunctival, and urogenital mucosal areas. A lymphocyte transformation test (LTT) was positive indicating an antigenic response to famotidine. The lesions completely resolved in 4 weeks after stopping famotidine and administering prednisolone, tobramycin, oxacillin, cefotaxime, and fluconazole.
Hematologic side effects including neutropenia have been reported. Rarely, reversible thrombocytopenia, agranulocytosis, pancytopenia, and leukopenia have been reported.
A case report of agranulocytosis eight days after the initiation of famotidine therapy has been reported in a 87-year-old male. After discontinuation of famotidine, initiation of empiric antibiotic use for the treatment of neutropenic fever, and administration of granulocyte-colony stimulating factor, the patient's white blood cell count and granulocyte count improved.
Respiratory side effects including bronchospasm and interstitial pneumonia have been reported infrequently.
Psychiatric side effects including depression, anxiety, insomnia, hallucinations, and decreased libido have been reported.
Musculoskeletal side effects have infrequently included rhabdomyolysis, musculoskeletal pain including muscle cramps and arthralgia.
Other side effects including tinnitus, fever, asthenia, fatigue, and taste disorder have been reported infrequently. At least one case of hyperpyrexia in association with famotidine (the active ingredient contained in Pepcid AC) use has been reported.
More about Pepcid AC (famotidine)
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