The February 2017 Drug Safety Update detailed the risk of serious adverse effects when hyoscine butylbromide injection (Buscopan) is administered to patients with underlying heart disease.

Hyoscine butylbromide is an antimuscarinic; it has both smooth muscle relaxant and antisecretory actions. Unlike the hydrobromide salt it does not cross the blood brain barrier and consequently does not cause drowsiness or have a central anti-emetic effect.

Therapeutically, hyoscine butylbromide injection is indicated for the relief of acute muscle spasm such as in renal or biliary colic.

Recognised side effects of hyoscine butylbromide include tachycardia, hypotension and anaphylaxis. This drug safety update advises healthcare professionals that these effects can be more serious in patients with pre-existing heart disease, such as heart failure, coronary heart disease, cardiac arrhythmia or hypertension.

MHRA have received 9[1] reports of patients who have died following administration of hyoscine butylbromide injection. In the majority of these reports the fatal reaction was described as acute myocardial infarction or cardiac arrest.

Healthcare professionals are advised that:

• hyoscine butylbromide injection is contra-indicated in patients with tachycardia.
• hyoscine hydrobromide injection should be used with caution in patients with existing cardiac disease.
• where administration is considered essential patients should be monitored closely. Resuscitation equipment and healthcare staff trained to use it should be readily available.

Pharmacists are also advised that any suspected adverse reactions should be reported to MHRA on a yellow card.