Jacob Hummel M.D. Tulane University Anesthesiology

* Know the different mechanisms of action for atropine, scopolamine and glycopyrrolate * Clinical use of each of these drugs * Effects on the cardiovascular, respiratory, cerebral, G.I. and other organ systems

* This is a really short lecture but its brevity does not reflect the value of its content

* This term is more indicative of what these drugs accomplish as they are primarily blocking the effects of acetylcholine at the muscarinic receptors

* Primary use is prior or concomitant administration with anticholinesterases * Crucial in the treatment of bradycardia * Beneficial in the prevention of PONV * Antisialogogues

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* Ester linkage essential for effective binding to the acetylcholine receptors, competitively inhibiting the binding of acetylcholine * Different types of muscarinic receptors: neuronal (M1), cardiac (M2), and glandular (M3)

* CARDIOVASCULAR * Blockade of the muscarinic receptors in the sinoatrial node results in tachycardia * Useful for reversing vagal reflexes

* RESPIRATORY * Inhibit secretions along the respiratory tract * Relaxes bronchial smooth muscle -> decreased airway resistance but increased dead space

* CEREBRAL * Range of effects, stimulation to depression * Physostigmine reverses these occurrences

* G.I. * Decreased secretions and salivation * Decreased peristalsis * Lower esophageal sphincter pressure reduced …better view, but more at risk for aspiration

* Other Effects * Mydriasis * Urinary retention * Reduced sweating, rise in body temp

* Potent effects on the heart and lungs * Most efficacious for treating bradycardia * Tertiary amine allows it to cross blood-brain barrier * Derivative is ipratropium bromide and used to treat bronchospasm * Use cautiously with heart disease, narrow angle glaucoma, BPH and bladder-neck obstruction Give me the atropine, NOW!

* Similar dosing to atropine, mg/kg with adult dose around mg * More potent antisialogogue than atropine * Greater CNS effects * Lipid solubility allows for the transdermal patch * Don’t touch your eyes after you put a patch on someone!

* Contains mandelic acid in place of the tropic acid seen in atropine * Dosing is usually half of the atropine dosing and used for similar effects (bradycardia, antisialogogue, etc.) * Quaternary structure prevents crossing of the blood- brain barrier * No ophthalmic activity * Potent antisialogogue * Longer duration of action than atropine (2-4 hrs. vs 30 minutes)

* An elderly patient is scheduled for enucleation of a blind, painful eye. Scopolamine, 0.4 mg intramuscularly, is administered as premedication. In the preoperative holding area, the patient becomes agitated and disoriented The only other medication the patient has received is 1% atropine eye drops * …how do you treat and would you proceed with the case?

* Signs and Symptoms * Agitation, delirium, unconsciousness * dry mouth, tachycardia, atropine flush, atropine fever, and impaired vision …antidote is physostigmine as it is the only anticholinesterase to cross the blood-brain barrier

* Elective Procedure * Is patient optimally medically managed? * Do symptoms resolve with intervention?

* GENERAL HUMMEL FROM ALCATRAZ….OUT!