The following convention has been utilised for the classification of undesirable effects: very common (>1/10), common (>1/100, <1/10), uncommon (>1/1000, <1/100), rare (>1/10,000, <1/1000), very rare (1/10,000).
Adverse event frequencies have been estimated from spontaneous reports from post-marketing data.
Hepatobiliary Disorders
Rare: Transient and reversible changes in liver function tests.
Very Rare: Hepatitis (hepatocellular, hepatocanalicular or mixed) with or without jaundice. These were usually reversible.
Gastrointestinal Disorders
Very Rare: Acute pancreatitis and diarrhoea.
Uncommon: Abdominal pain, constipation, nausea. (these symptoms mostly improved during continued treatment).
Blood & Lymphatic System Disorders
Very rare: Blood count changes (Leucopenia and thrombocytopenia). These are usually reversible. Agranulocytosis or pancytopenia, sometimes with marrow hypoplasia or aplasia.
Immune System Disorders
Rare: Hypersensitivity reactions (urticaria, angioneurotic oedema, fever, bronchospasm, hypotension, chest pain)
Very rare: Anaphylactic shock.
These reactions have occasionally occurred after a single dose.
Cardiac Disorders
Very Rare: As with other H2 receptor antagonists bradycardia and A-V block.
Nervous System Disorders
Very rare: Headache (sometimes severe), dizziness and reversible involuntary movement disorders.
Psychiatric Disorders
Very rare: reversible mental confusion, depression and hallucinations
These have been reported, predominantly in severely ill and elderly patients.
Skin and Subcutaneous Tissue Disorders
Rare: Skin rash
Very rare: erythema multiforme and alopecia.
Musculoskeletal and Connective Tissue Disorders
Very rare: Musculoskeletal symptoms such as arthralgia and myalgia
Eye Disorders
Very Rare: Reversible blurred vision.
There have been reports of blurred vision, which is suggestive of a change of accommodation.
Vascular Disorders
Very Rare: Vasculitis
Renal and Urinary Disorders
Very Rare: Acute interstitial nephritis
Rare: Elevation of plasma creatinine (usually slight; normalised during continued treatment)
Reproductive System and Breast Disorders
Very Rare: Reversible impotence. Breast symptoms and conditions (such as gynaecomastia and galactorrhea)
Discontinuation of therapy may be necessary in order to establish the underlying cause.
No clinically significant interference with endocrine or gonadal function has been reported.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.