Hyoscine butylbromide
Class: antispasmodic – gastrointestinal tract
Indications (NB some may be unlicensed): GI spasm/colic, some action as anti-emetic and antisecretory, sialorrhoea, excessive respiratory secretions
Contraindications/cautions: toxic megacolon,pyloric stenosis, glaucoma, prostatic enlangement; tachycardia, urinary retention
Adverse reactions: common: dry mouth; less common: urinary retention, tachycardia, visual problems, dizziness, constipation
Metabolism/clearance: metabolised but also some excreted unchanged by the kidneys so care in renal dysfunction
Interactions:
- additive anticholinergic effects (e.g. dry mouth, urinary retention) may occur with other drugs which have anticholinergic effects e.g. cyclizine, amitriptyline, phenothiazines (e.g. chlorpromazine)
- decreased clinical effect (prokinetic effects) of metoclopramide/domperidone may occur with concomitant hyoscine butylbromide
| Dosing: | |
|---|---|
| oral: | 20 mg 4 times a day |
| subcut: | 40 to 100 mg/24 hours |
| rectal: | not available |
Syringe driver: see syringe driver compatibility chart
Mechanism of action: blocks the effect of acetylcholine on gastrointestinal smooth muscle causing relaxation
Onset: oral: 1 to 2 hours subcut: 5 to 10 minutes
Duration: oral: 2 hours or less
Notes:
- may be useful with steroids in intestinal obstruction
- doesn’t cross the blood-brain barrier so doesn’t cause drowsiness or have a central antiemetic action
- only 8 to 10% absorbed orally