Glycopyrrolate

Indications

Glycopyrrolate is used for: In Anesthesia: • As a pre-operative antimuscarinic agent to reduce salivary, tracheobronchial and pharyngeal sections and to reduce the acidity of the gastric contents. • As a pre-operative or intra-operative antimuscarinic to attenuate or prevent intra-operative bradycardia with the use of suxamethonium or due to cardiac vagal reflexes. • To protect against the peripheral muscarinic actions of anticholinesterases such as neostigmine and pyridostigmine, used to reverse residual neuromuscular blockade produced by non- depolarising muscle relaxants. In Peptic Ulcer: For use in adults as adjunctive therapy for the treatment of peptic ulcer when rapid anticholinergic effect is desired or when oral medication is not tolerated. Hyperhidrosis, Sialorrhea, Cerebral palsy.

Adult Dose

Parenteral Reduction of secretions Adult: Preoperative: 4 mcg/kg via IM admin 30-60 minutes before procedure. Intraoperative: 0.1 mg via IV admin, repeat at 2-3 minute intervals when needed. Max: 400 mcg/dose. Intravenous Reversal of neuromuscular blockade Adult: 200 mcg for each 1 mg of neostigmine or 5 mg of pyridostigmine. Alternatively, 5-15 mcg/kg with 50 mcg/kg neostigmine with 25-70 mcg/kg of neostigmine or 0.1-0.3 mg/kg of pyridostigmine. Parenteral Peptic ulcer Adult: 0.1-0.2 mg 3-4 times daily via IM/IV admin.

Child Dose

Parenteral Reduction of secretions Child: Preoperative: IM admin: <2 yr: 4-9 mcg/kg; >2 yr: 4 mcg/kg, dose to be given 30-60 minutes before procedure. Intraoperative: IV admin: 4 mcg/kg (Max: 0.1 mg); repeat at 2-3-minute intervals as needed. Max Dosage: Child >1 mth: 200 mcg/dose. Intravenous Reversal of neuromuscular blockade Child: 10 mcg/kg with 50 mcg/kg neostigmine.

Renal Dose

Administration

Contra Indications

Angle-closure glaucoma; myasthenia gravis (large doses of quaternary ammonium compounds have been shown to block end plate nicotinic receptors); paralytic ileus; pyloric stenosis; prostatic enlargement. Anticholinesterase-antimuscarinic combinations such as neostigmine plus glycopyrronium should be avoided in patients with a prolonged QT interval.

Precautions

Antimuscarinics should be used with caution (due to increased risk of side effects) in Down’s syndrome, in children and in the elderly. They should also be used with caution in gastro-esophageal reflux disease, diarrhea, ulcerative colitis, acute myocardial infarction, hypertension, conditions characterized by tachycardia (including hyperthyroidism, cardiac insufficiency, cardiac surgery) because of the increase in heart rate produced by their administration, coronary artery disease and cardiac arrhythmias, pyrexia (due to inhibition of sweating), pregnancy and breast feeding. Because of prolongation of renal elimination, repeated or large doses of glycopyrronium bromide should be avoided in patients with uremia. Large doses of quaternary anticholinergic compounds have been shown to block end plate nicotinic receptors. This should be considered before using glycopyrrolate in patients with myasthenia gravis. It is known that the administration of anticholinergic agents during inhalation anesthesia can result in ventricular arrhythmias. Lactation: Excretion in milk unknown; use with caution

Pregnancy-Lactation

Interactions

Decreases levodopa effects. Effects may be enhanced by using drugs with antimuscarinic properties or MAOIs concurrently. May antagonise the GI effects of cisapride, metoclopramide and dompeidone. Potentially Fatal: IV admin in the presence of cyclopropane anesth can result in ventricular arrhythmias.

Adverse Effects

Side effects of Glycopyrrolate : Anticholinergic symptoms (mydriasis, hyperthermia, tachycardia, cardiac arrhythmia),Dry mouth,Dry skin,Anhidrosis,Flushing,Blurred vision,Cycloplegia,Photophobia,Palpitation,Xerophthalmia,Constipation,Urinary retention Potentially Fatal: Severe anaphylaxis.

Mechanism of Action

Glycopyrronium bromide is a quarternary ammonium antimuscarinic. It blocks acetylcholine at parasympathomimetic sites and induces smooth muscle relaxation. It also reduces gastric acid secretions and controls pharyngeal, tracheal and bronchial secretions. It antagonises muscarinic symptoms such as bronchorrhoea, bronchospasm, bradycardia and intestinal hypermotility induced by anticholinesterases.