Antimuscarinics/anticholinergics such as hyoscine hydrobromide, atropine, glycopyrronium/glycopyrrolate, hyoscine butylbromide 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 the end of life. Hyoscine hydrobromide and glycopyrronium/glycopyrrolate are less likely to cross the blood-brain barrier as they are less lipid-soluble thereby causing fewer central side-effects (e.g. delirium).
Effective in reducing respiratory secretions at end of life in about ½-⅓ of patients

Onset of action: < 30 minutes SC/IM/IV; 50 minutes PO
Duration of inhibition of salivation: 7 h


  • 0.4 mg as a single dose SC. Then if effective, continue using 0.2 mg q4h and prn SC
  • 4-10 mcg/kg q6h (max of 200 mcg/dose) IV/SC


  • Blurred vision
  • Cardiovascular effects
  • Dry mouth
  • Constipation
  • Heartburn
  • Urinary retention
  • Delirium


  • Avoid concurrent use with prokinetics as antimuscarinics will block the action of agents such as metoclopramide
  • Glaucoma may be precipitated in patients at risk


This information is drawn from a number of sources (see below). The reader is encouraged to access these and other relevant literature for more detail. As always, sound clinical judgment should be used in individual clinical cases. In particular, it should be remembered that there may be significant variation in the pharmokinetics of a drug resulting from a number of factors, including the individual patient’s metabolism/disease status and how the medication has been formulated.


  1. Brunton LL, Lazo JS, Parker KL, editors. Goodman and Gilman’s: the pharmacological basis of therapeutics. 11th ed. McGraw-Hill Professional; 2006.
  2. Twycross R, Wilcock A. Palliative care formulary. 3rd ed. Radcliffe Medical Press Ltd; 2008.
  3. Repchinsky C, editor. Compendium of pharmaceuticals and specialties (CPS): the Canadian drug reference for health professionals. 44th ed. Canadian Pharmacists Association; 2009.
  4. Goldman A, Hain R, Liben S. Oxford textbook of palliative care for children. 1st ed. Oxford University Press; 2006.

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