6.1 Clinical Trial Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials
of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed
in practice.
Famotidine was studied in 7 US and international placebo- and active-controlled trials in approximately 2500 patients [see
Clinical Studies (14)]. A total of 1442 patients were treated with Famotidine , including 302 treated with 40 mg twice daily,
456 treated with 20 mg twice daily, 461 treated with 40 mg once daily, and 396 treated with 20 mg once daily. The
population was 17-91 years old, fairly well distributed between gender and race; however, the predominant race treated
was Caucasian.
The following adverse reactions occurred in greater than or equal to 1% of Famotidine -treated patients: headache, dizziness
and constipation.
The following other adverse reactions were reported in less than 1% of patients in clinical trials:
Body as a Whole: fever, asthenia, fatigue
Cardiovascular: palpitations
Gastrointestinal: elevated liver enzymes, vomiting, nausea, abdominal discomfort, anorexia, dry mouth
Hematologic: thrombocytopenia
Hypersensitivity: orbital edema, rash, conjunctival injection, bronchospasm
Musculoskeletal: musculoskeletal pain, arthralgia
Nervous System/Psychiatric: seizure, hallucinations, depression, anxiety, decreased libido, insomnia, somnolence
Skin: pruritus, dry skin, flushing
Special Senses: tinnitus, taste disorder
Other: impotence
6.2 Postmarketing Experience
The following adverse reactions have been identified during post-approval use of famotidine. Because these reactions are
reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or
establish a causal relationship to drug exposure.
Cardiovascular: arrhythmia, AV block, prolonged QT interval
Gastrointestinal: cholestatic jaundice, hepatitis
Hematologic: agranulocytosis, pancytopenia, leukopenia
Hypersensitivity: anaphylaxis, angioedema, facial edema, urticaria
Musculoskeletal: rhabdomyolysis, muscle cramps
Nervous System/Psychiatric: confusion, agitation, paresthesia
Respiratory: interstitial pneumonia
Skin: toxic epidermal necrolysis/Stevens-Johnson syndrome