Glycopyrrolate (Robinul)

Anesthesia Implications

Classification: Antimuscarinic, Anticholinergic, Quaternary Amine
Therapeutic Effects: Reduced secretions, increased HR

Duration: 2-4 hours IV; 6-8 hours IM

Contraindications

Narrow angle glaucoma (increased intraoccular pressure)
Tachycardia
Aortic Stenosis

Primary Considerations

Primary drug to reduce oral secretions perioperatively.  This is especially helpful for awake intubations, bronchoscopy, side effects of ketamine, etc.

Glycopyrrolate is not as effective at increasing HR as is atropine – but it is still used as much, if not more, for this purpose (more especially in adult populations). It is advantageous over atropine in that it does NOT cross the blood-brain barrier.  This makes it advantageous in avoiding the CNS affects of atropine and scopolomine.

Glycopyrrolate is also used in combination with Neostigmine as a reversal agent.  Neostigmine is the actual reversal agent.  The administration of glycopyrrolate is to combat the bradycardia associated with Neostigmine and is preferred over atropine because the changes in heart rate are less acute.  Again, The other benefit is that it does not cross the BBB.  Glycopyrrolate and atropine both work FASTER than neostigmine – which is why clinically, they are often administered at the same time.

Incidence of PONV are NOT increased with the use of Neostigmine when appropriately paired with glycopyrrolate.

Glycopyrrolate may be used to prevent acetylcholine-induced bronchoconstriction.

Safe for malignant hyperthermia

Spinal anesthesia-induced bradycardia is refractory to glycopyrrolate and should NOT be used as an attempt to increase HR.  However, spinal anesthesia-induced bradycardia for cesarean delivery is NOT refractory to glycopyrrolate and can be used to increase the heart rate.  Otherwise, atropine and ephedrine should be used for this purpose.

Lowers the tone of the lower esophageal sphincter.  This warrants caution in patients at risk for aspiration (particularly parturients).

Used as an agent to counterbalance the parasympathetic responses to electroconvulsive therapy (ECT)

Glycopyrrolate can be used to reverse bradycardia after administration of succinylcholine.  However, atropine is far more commonly used for this purpose in the clinical setting.

Neonates
May be used to prevent the reduction in heart rate experienced during intubation in response to vagal stimulation  (see dosing below)

IV push dose

For Bradycardia:
0.1 – 0.4 mg, titrated to affect (adult)

Neuromuscular block reversal adjunct:
0.2 mg for every 1 mg of Neostigmine

Succinylcholine-induced bradycardia prophylaxis (PEDs):
5-10 ug/kg before succinylcholine

IM dose

0.2-0.4 mg for antisialagogue affect

Method of Action

Competes for acetylcholine receptors, thereby reducing the acetylcholine affects and parasympathetic tone. This leaves sympathetic tone unchecked (or less checked), so sympathetic affects will increase (increased HR, reduced GI motility, reduced secretions, etc).

Elimination

Renal