Hyoscine butylbromide - a review on its parenteral use in acute abdominal spasm and as an aid in abdominal diagnostic and therapeutic procedures.

Being a quaternary ammonium compound derived from scopolamine, the alkaloid hyoscine butylbromide (HBB) exerts anticholinergic effects without side effects related to the central nervous system because it does not pass the blood-brain barrier. Clinical experience with this antispasmodic dates back to the 1950s and led to its registration for treating abdominal cramps/spasm and for diagnostic imaging purposes. OBJECTIVES AND SCOPE: This review focuses on the therapeutic efficacy and safety of the parenteral administration of HBB for treating biliary and renal colic and acute spasm in the genito-urinary tract. In addition, its value for diagnostic or therapeutic procedures in the abdomen, as well as for labour and palliative care, is reviewed. With the generic and trade name of the drug combined with various search terms related to the relevant clinical applications, a thorough literature search was performed in the Medline and EMBASE databases in April 2008. In most clinical studies, recommended doses of 20-40 mg HBB were injected, mainly intravenously. Fast pain reduction was achieved by HBB in renal colic; about 90% of the patients showed good to moderate analgesic responses after 30 min and the onset of action was noticeable within 10 min. Similarly, a pain reduction of 42-78% was observed in patients with biliary colic within 30 min after a single intravenous injection of 20 mg. In contrast, no analgesic efficacy of a single injection of 20 mg was found after surgical or shock-wave procedures in the urogenital area. Administration of HBB prior to, or during, radiological imaging distended the gastrointestinal (GI) tract in double-contrast barium and computed tomographic colonography studies and reduced motion artefacts in magnetic resonance imaging. This improved diagnostic image quality and organ visualisation. Pre-medication led to shorter and easier endoscopy in some, but not all, studies. Because of cervical relaxation, HBB shortened total labour duration with 17-67%. It also relieved pain and reduced GI secretions in terminal cancer patients with inoperable bowel obstruction. With regard to its safety profile, parenteral administration of HBB is associated with mild and self-limiting adverse events, typical for anticholinergic drugs. These clinical results of rapid action and beneficial efficacy combined with good tolerability support the use of HBB in a range of indications related to acute abdominal spasm, in labour and palliative care and for supporting diagnostic and therapeutic abdominal procedures, where spasm may be a problem.