Many of the listed undesirable effects can be assigned to the anticholinergic properties of hyoscine butylbromide.
Undesirable effects are listed by system organ classes by using the following frequency convention:
Very common | ≥ 1/10 |
Common | ≥ 1/100, <1/10 |
Uncommon | ≥ 1/1,000, <1/100 |
Rare | ≥ 1/10,000, <1/1,000 |
Very rare | <1/10,000 |
Not known | cannot be estimated from the available data |
Immune system disorders
Not known*: anaphylactic shock including cases with fatal outcome, anaphylactic reactions, dyspnoea, skin reactions (e.g. urticaria, rash, erythema, pruritus) and other hypersensitivity reactions.
Eye disorders
Common: accommodation disorders.
Not known*: mydriasis, increased intraocular pressure.
Cardiac disorders
Common: tachycardia.
Vascular disorders
Common: dizziness.
Not known*: blood pressure decreased, flushing.
Gastrointestinal disorders
Common: dry mouth, constipation.
Skin and subcutaneous tissue disorders
Not known*: dyshidrosis.
Renal and urinary disorders
Not known*: urinary retention.
Injection site pain, particularly after intramuscular use, occurs.
Hyoscine butylbromide due to its chemical structure as a quaternary ammonium derivate, is not expected to enter the central nervous system. Hyoscine butylbromide does not readily pass the blood-brain barrier. However, it cannot totally be ruled out that under certain circumstances psychiatric disorders (e.g. confusion) may also occur after administration of this medicine.
*This adverse reaction has been observed in post-marketing experience. With 95% certainty, the frequency category is not greater than 'common', but might be lower. Precise frequency estimation is not possible as the adverse drug reaction did not occur in a clinical trial database of 185 patients.
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 the Yellow Card Scheme, Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.