Glycopyrronium (Glycopyrrolate)
Glycopyrronium bromide
Also known as: Robinul · Glycopyrrolate · Glycopyrronium bromide
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Dosing by species
Dosing data for this drug is not yet available in the VetSheet formulary. Every other section below is complete. Consult the current product label before prescribing.
Overview
Glycopyrronium (also known as glycopyrrolate) is a potent anticholinergic and antisialagogue agent. It is primarily used in veterinary anesthesia to decrease oral and bronchial secretions, inhibit vagal efferent activity, and manage bradycardia caused by the administration of potent opioid drugs. It is also used alongside long-acting anticholinesterase drugs (e.g., neostigmine, pyridostigmine) to antagonize neuromuscular blockade.
Clinical Warning: Routine administration of glycopyrronium prior to anesthesia as part of premedication is no longer recommended. It reduces secretions by decreasing water content, which makes airway secretions more sticky and difficult to clear.
Mechanism of action
Competitively blocks the action of acetylcholine at muscarinic receptors at the terminal ends of the parasympathetic nervous system → reverses parasympathetic effects (e.g., increases heart rate, reduces salivation).
Clinical Pearl: Because of its quaternary ammonium structure, glycopyrronium cannot cross the blood-brain barrier. Therefore, it is devoid of central nervous system effects and does not cause central mydriasis, unlike atropine. It also has a longer duration of action compared to atropine.
Safety & warnings
Contraindications
- Concurrent use with alpha-2 adrenergic agonists is not recommended
Adverse effects
- Tachycardia
- Ventricular arrhythmias
- Thickened, sticky airway secretions
- Paradoxical bradycardia (at very low IV doses)
Precautions
- Paradoxical Bradycardia: Administration of very low doses of glycopyrronium IV can cause exacerbation of bradyarrhythmias due to a vagal stimulatory effect. Giving another dose IV will usually cause an increase in heart rate.
- Airway Secretions: Decreases the water content of oral and bronchial secretions, making them more sticky.
- Opioid Bradycardia: It is better to monitor heart rate and give glycopyrronium to manage a low heart rate only if necessary, rather than as a routine premedication.
Drug interactions
In vitro incompatibility; a precipitate may form if mixed together
Antimuscarinics may enhance the actions of sympathomimetics
Antimuscarinics may enhance the actions of thiazide diuretics
May enhance the anticholinergic activity of glycopyrronium
May enhance the anticholinergic activity of glycopyrronium
May enhance the anticholinergic activity of glycopyrronium
May enhance the anticholinergic activity of glycopyrronium
Combining glycopyrronium and alpha-2 adrenergic agonists is not recommended due to conflicting cardiovascular effects
Monitoring
- Heart rate and rhythm (ECG)
- Respiratory rate and airway patency
Pharmacokinetics
Absorption
Rapidly absorbed following IM or SC administration.
Distribution
Does not cross the blood-brain barrier or placenta significantly due to its quaternary ammonium structure.
Metabolism
Undergoes minimal hepatic metabolism.
Elimination
Excreted primarily unchanged in the urine and feces.
Overdose
Tachycardias following an overdose of glycopyrronium are usually transient and do not require management. If severe ventricular arrhythmias occur, they may be treated with lidocaine.
Available products
Formulations
- Injectable: 200 μg/ml solution
Veterinary
- Robinul 200 μg/ml solution for injection
Human-labeled
- Robinul 200 μg/ml solution for injection
Regulatory status
POM (Prescription Only Medicine)
POM-V
No regulatory data for: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Normal precautions should be observed. Store at room temperature and protect from light.
Client information
This medication is typically administered by a veterinarian in a clinic or hospital setting during anesthesia or surgery. It is used to safely manage your pet's heart rate and reduce excessive saliva and airway secretions while they are under anesthesia.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.