Famotidine Side Effects

Medically reviewed by Drugs.com. Last updated on Jul 22, 2024.

Applies to famotidine: oral powder for suspension, oral tablet.

Precautions

It is very important that your doctor check your or your child's progress at regular visits to make sure this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

If your condition does not improve, or if it become worse, check with your doctor.

Check with your doctor right away if you have the following symptoms: confusion, delirium, hallucinations, disorientation, agitation, seizures, or unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness. These are more likely to occur if you are older or if you have a kidney disease.

Contact your doctor right away if you have any changes to your or your child's heart rhythm. You or your child might feel dizzy or faint, or you or your child might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you had a heart rhythm problem, such as QT prolongation.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Common side effects of famotidine

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:

Serious side effects of famotidine

Along with its needed effects, famotidine 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:

For healthcare professionals

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

General adverse events

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

Gastrointestinal

• Common (1% to 10%): Constipation, diarrhea
• Uncommon (0.1% to 1%): Nausea, vomiting, flatulence, dry mouth, abdominal discomfort or distension^[Ref]

Nervous system

• 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]

Convulsions occurred in patients with renal dysfunction.^[Ref]

Dermatologic

• 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]

Other

• Uncommon (0.1% to 1%): Fatigue
• Frequency not reported: Asthenia, fatigue, facial/orbital edema, tinnitus^[Ref]

Metabolic

• Uncommon (0.1% to 1%): Loss of appetite
• Frequency not reported: Anorexia^[Ref]

Hematologic

• Rare (0.01% to 0.1%): Thrombocytopenia, leukopenia, agranulocytosis, pancytopenia
• Frequency not reported: Neutropenia^[Ref]

Hepatic

• 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]

Hypersensitivity

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

Respiratory

• Rare (0.01% to 0.1%): Bronchospasm
• Frequency not reported: Interstitial pneumonia^[Ref]

Musculoskeletal

• Rare (0.01% to 0.1%): Arthralgia
• Very rare (less than 0.01%): Muscle cramps
• Frequency not reported: Rhabdomyolysis, musculoskeletal pain^[Ref]

Psychiatric

• Very rare (less than 0.01%): Hallucinations, disorientation, confusion, anxiety, agitation, depression, reduced libido, insomnia
• Frequency not reported: Psychic disturbances^[Ref]

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

Cardiovascular

• Very rare (less than 0.01%): Chest tightness, prolonged QT interval
• Frequency not reported: Arrhythmia, atrioventricular block, palpitation^[Ref]

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

Genitourinary

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

Ocular

• Frequency not reported: Conjunctival injection^[Ref]

Endocrine

• Frequency not reported: Gynecomastia^[Ref]

See also:

Frequently asked questions

• Is famotidine safer than omeprazole for heartburn?
• Can you take famotidine long term?
• Can I take omeprazole in the morning and famotidine at night?

Further information

Famotidine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer