A Medicines Safety Update from the TGA has reminded health professionals to be cautious with parenteral administration of hyoscine butylbromide (Buscopan) via intramuscular or slow intravenous injection.

The Product Information for hyoscine butylbromide is being updated to include a stronger warning about its use in patients with cardiac conditions.

The updated PI will advise that ampoules of the antispasmodic should be used with caution in patients with pre-existing cardiac conditions such as cardiac failure, coronary heart disease, cardiac arrhythmia or hypertension, and in cardiac surgery.

Hyoscine butylbromide, used to treat spasm of the gastrointestinal tract, biliary spasm and renal spasm, and as a diagnostic aid in radiology, can cause tachycardia, hypotension and anaphylaxis.

These adverse events can be more serious in patients with pre-existing cardiac conditions.

Monitoring of these patients is therefore advised and emergency equipment and personnel trained in its use must be readily available.

There are 28 cases describing tachycardia and/or hypotension and four cases describing anaphylactic reactions relating to the use of hyoscine butylbromide in the TGA’s adverse events database.