Anticholinergic (Muscarinic Antagonist) — Perioperative Pregnancy: SPC §4.6: use in human pregnancy has not been systematically evaluated; the product should only be used in pregnancy if considered essential. Breast-feeding: may reach breast milk but in amounts probably too small to be harmful — caution is advised when considering administration to a nursing mother. No data on effects on male or female fertility.

Glycopyrronium (Perioperative — Anticholinergic)

Brand names: Robinul

Glycopyrronium is a quaternary antimuscarinic (anticholinergic) used perioperatively to reduce airway and salivary secretions and to counteract vagally mediated bradycardia.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Premedication: 200 to 400 micrograms (0.2 to 0.4 mg); alternatively 4 to 5 micrograms/kg (0.004 to 0.005 mg/kg)

Route: Intravenous or intramuscular injection (glycopyrronium bromide 200 micrograms/ml solution for injection)

Frequency: Single dose before the induction of anaesthesia

Max: When dosed on a per-kg basis, up to a maximum of 400 micrograms (0.4 mg). Larger doses may result in a profound and prolonged antisialagogue effect which may be unpleasant for the patient.

SPC §4.2 gives the same doses for adults and the elderly. INTRA-OPERATIVE USE (adults and elderly): a single dose of 200 to 400 micrograms (0.2 to 0.4 mg) by intravenous injection; alternatively a single dose of 4 to 5 micrograms/kg (0.004 to 0.005 mg/kg) up to a maximum of 400 micrograms (0.4 mg). This dose may be repeated if necessary. REVERSAL OF RESIDUAL NON-DEPOLARISING NEUROMUSCULAR BLOCK (adults and elderly): 200 micrograms (0.2 mg) intravenously per 1000 micrograms (1 mg) neostigmine or the equivalent dose of pyridostigmine; alternatively 10 to 15 micrograms/kg (0.01 to 0.015 mg/kg) intravenously with 50 micrograms/kg (0.05 mg/kg) neostigmine or an equivalent dose of pyridostigmine. The SPC states glycopyrrolate injection may be administered simultaneously from the same syringe with the anticholinesterase, and that greater cardiovascular stability results from this method of administration. §4.3 states that anticholinesterase-antimuscarinic combinations such as neostigmine plus glycopyrronium should be avoided in patients with a prolonged QT interval. §4.4: quaternary ammonium compound that does not cross the blood-brain barrier, so less likely than atropine to cause postoperative confusion; reduced cardiovascular and ocular effects compared with atropine; anticholinergic drugs can cause ventricular arrhythmias when administered during inhalation anaesthesia, especially with halogenated hydrocarbons; as glycopyrrolate inhibits sweating, patients with increased temperature (especially children) should be observed closely. Method of administration: intravenous or intramuscular injection only.

Paediatric dose

Route: Intravenous or intramuscular injection

Frequency: Single dose before the induction of anaesthesia (premedication)

Max: 200 micrograms (0.2 mg)

UNITS ARE MICROGRAMS PER KG, NOT MILLIGRAMS PER KG. dosePerKg is left null because the SPC states a RANGE, not a single figure. VERBATIM SPC §4.2 'Paediatric population' — PREMEDICATION: '4 to 8 micrograms/kg (0.004 to 0.008mg/kg) up to a maximum of 200 micrograms (0.2mg) intravenously or intramuscularly before the induction of anaesthesia. Larger doses may result in profound and prolonged antisialagogue effect which may be unpleasant for the patient.' INTRA-OPERATIVE USE: 'A single dose of 200 micrograms (0.2mg) by intravenous injection should be used. Alternatively, a single dose of 4 to 8 micrograms/kg (0.004 to 0.008mg/kg) up to a maximum of 200 micrograms (0.2mg) may be used. This dose may be repeated if necessary.' REVERSAL OF RESIDUAL NON-DEPOLARISING NEUROMUSCULAR BLOCK: '10 micrograms/kg (0.01mg/kg) intravenously with 50 micrograms/kg (0.05mg/kg) neostigmine or the equivalent dose of pyridostigmine', which may be given simultaneously from the same syringe with the anticholinesterase. §4.4 warns that antimuscarinics should be used with caution (increased risk of side effects) in Down's syndrome, in children and in the elderly, and that because glycopyrrolate inhibits sweating, patients with increased temperature (especially children) should be observed closely. Verify all under-18 dosing against a children's formulary before administration.

Dose adjustments

Renal

No dose adjustment is stated in §4.2. §4.4 states: 'Because of prolongation of renal elimination, repeated or large doses of Glycopyrronium Bromide should be avoided in patients with uraemia.'

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Anticholinesterase-antimuscarinic combinations such as neostigmine plus glycopyrronium should be avoided in patients with a prolonged QT interval
Myasthenia gravis — quaternary ammonium compounds in large dose have been shown to block the nicotinic muscle end plate receptors; this must be evaluated prior to administration
Listed within §4.3 as cautions rather than absolute contraindications: prostatic hypertrophy, paralytic ileus, pyloric stenosis and closed angle glaucoma (in common with other antimuscarinic drugs)

Side effects

Tachycardia and palpitations (frequency not known); bradycardia followed by tachycardia, palpitation and arrhythmias
Dry mouth
Accommodation disorder; photophobia; angle closure glaucoma (very rare)
Anhidrosis (inhibition of sweating) and dry skin; flushing
Micturition disorder, micturition urgency, urinary retention
Confusion (particularly in the elderly) and dizziness; hypersensitivity and angioedema

Interactions

Other drugs with antimuscarinic effects (MAOIs, amantadine, clozapine, tricyclic antidepressants, disopyramide, antihistamines, pethidine, phenothiazines, nefopam) — increased antimuscarinic side effects such as dry mouth, urine retention and constipation, and confusion in the elderly
Anticholinergic agents may delay the absorption of other medication given concomitantly
Corticosteroids — concurrent administration with anticholinergics may result in increased intraocular pressure
Digoxin (slow-dissolving tablets) — may cause increased serum digoxin levels
Domperidone / metoclopramide — antagonism of effect on gastro-intestinal activity; parasympathomimetics — antagonism of effect
Ketoconazole — reduced absorption; levodopa — absorption possibly reduced; memantine — effects of glycopyrronium possibly enhanced; sublingual nitrates — possibly reduced effect (failure to dissolve under the tongue owing to dry mouth); ritodrine — tachycardia

Clinical monograph

How it works

It competitively blocks muscarinic acetylcholine receptors, reducing secretions and increasing heart rate; its quaternary structure limits central nervous system penetration.

Prescribing in practice

Use with caution in patients with tachyarrhythmias, ischaemic heart disease, glaucoma, prostatic enlargement or bowel obstruction, as antimuscarinic effects may be harmful.
Frequently co-administered with neostigmine during neuromuscular blockade reversal to offset muscarinic effects such as bradycardia.
It crosses the placenta poorly and causes less central effect than tertiary antimuscarinics such as atropine.

Monitoring

Monitor heart rate and rhythm during and after administration in the perioperative setting.

Counselling the patient

A dry mouth and transient blurred vision may occur after the procedure.
Inform the anaesthetic team of any heart rhythm problems or glaucoma.

Evidence & guidelines

Antimuscarinics are standard perioperative agents for antisialagogue effect and as part of neuromuscular blockade reversal, supported by established anaesthetic practice.

Reference: AAGBI Reversal of Neuromuscular Block Guidelines; RCoA Anaesthetic Guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways