Antimuscarinics/anticholinergics — such as hyoscine hydrobromide, atropine, glycopyrronium/glycopyrrolate, hyoscine butyl bromide — are used primarily as smooth muscle antispasmodics and antisecretory agents.
They are used in palliative care for intestinal colic, genitorurinary colic, inoperable bowel obstruction with colic, and respiratory secretions at end of life.
Hyoscine butylbromide and glycopyrronium/glycopyrrolate are less likely to cross the blood-brain barrier as they are not as lipid-soluble, thereby causing less central side effects (e.g., delirium).
Effective in reducing respiratory secretions at end of life in about one-half to one-third of patients.
Onset of action: < 10 minutes SC/IM/IV
Plasma ½ life: 5-6 h
0.4 mg as a single dose SC
If effective, continue using 0.3-0.6 mg q4h SC
Onset of action: 10 minutes SC/IM/IV. Time to peak plasma concentration: 1-2 h PO
20 mg as a single dose SC. If effective, continue, using 20 mg q4h SC
Adverse drug reactions
: blurred vision, cardiovascular effects, dry mouth, constipation, heartburn, urinary retention, delirium.
INCTR Palliative Care Handbook. Internet. Accessed on August 21, 2011.