Glycopyrrolate (glycopyrronium bromide)
Class: antimuscarinic – antisecretory/antispasmodic
Indications (NB some may be unlicensed): antisecretory premedication, excessive respiratory secretions; antispasmodic & inoperable intestinal obstruction; paraneoplastic pyrexia & sweating; localised hyperhidrosis
Contraindications/cautions: urinary retention, prostatic enlargement, glaucoma, myasthenia gravis; paralytic ileus, pyloric stenosis
Adverse reactions: common: dry mouth, tachycardia; less common: urinary retention, visual problems, dizziness, constipation, drowsiness,nausea, vomiting
Metabolism/clearance: excreted in the bile and unchanged by the kidneys
Interactions:
- additive anticholinergic effects (e.g. dry mouth, urinary retention) with other drugs which have anticholinergic effects e.g. cyclizine, amitriptyline, haloperidol, phenothiazines (e.g. chlorpromazine)
- decreased clinical effect (prokinetic effects) of metoclopramide/domperidone may occur with concomitant glycopyrrolate
| Dosing: | |
|---|---|
| oral: | not available (not absorbed orally) |
| subcut: | 200 micrograms up to every 4 hours when required; occasionally hourly use is necessary |
| Syringe driver: | 600 micrograms to 1200 micrograms (0.6 to 1.2 mg) over 24 hours |
| rectal: | not available |
| Topical: | Can be applied topically to treat localised hyperhidrosis as a 0.5 to 4% cream or aqueous solution once to twice daily – avoid eyes, nose & mouth – do not wash treated skins for 3 to 4 hours (unregistered) |
Syringe driver: see compatibility chart – incompatible with dexamethasone
Mechanism of action: blocks cholinergic receptors
Initial response (im): 30 to 45 minutes
Duration: (im): 7 hours
Notes:
- may be a useful alternative to hyoscine particularly in the elderly because it is less likely to cause CNS adverse effects as it does not readily cross the blood brain barrier