Anticholinergics/Acetylcholinesterases Flashcards

Question

Scopolamine

Answer 1

Naturally occurring, tertiary amine, crosses BBB

Answer 2

Prevent ACh binding at the muscarinic receptors | Can be overcome with increased ACh

Answer 3

Sedation (atropine/scopolamine-cross BBB), antisialagogue, increase HR, relax smooth muscle, mydriasis (dilate pupil), prevention of motion sickness (reticular system in brain-scopolamine), decrease gastric ion secretion

Answer 4

Onset: atropine (1-2 min), glycopyrrolate (2-3 min) Duration: both last 30-60 min

Answer 5

Absorption: lipid solubility. Atropine and scopolamine are tertiary amines and cross the BBB to have CNS effects (sedation) Clearance: glycopyrrolate has faster clearance. All cleared by the kidneys, but renal failure is not a contraindication

Answer 6

Important uses include: preop meds, tx of bradycardia, and NDNMB reversal Less common uses include: bronchodilation, smooth muscle relaxant (biliary and uretal), antagonism of gastric acid secretion, prevent N/V Caution: glaucoma and parturients

Answer 7

Anticholinergics can be used as premeds for sedation, antisialogogue, bradycardia treatment

Answer 8

Scopolamine (0.4 mg IV) is the most potent. Works at the reticular activating system in the brain. Amnesia. Atropine has memory deficit and delayed arousal. Not as much amnesia properties as scopolamine. Glycopyrrolate has no sedation effects (quaternary amine) CNS effects: atropine and scopolamine because cross BBB

Answer 9

Scopolamine most potent, but it also has sedative properties so be cautious. 3x more potent than atropine. Less HR changes. Glycopyrrolate (0.2 mg IM = more potent antisailagogue effect than IV and doesn’t increase HR as much). 2x more potent than atropine. Used when sedative properties not wanted

Answer 10

Blocks ACh at the SA node, decreased parasympathetic effects, works on cardiac muscarinic receptors Glycopyrrolate = atropine in effectiveness, but the onset of glycopyrrolate is slower Good for vagal response in eye sx (ocularocardio reflex) and colon resections (peritoneal stretch response = decreased HR)

Answer 11

Works on muscarinic receptors on the smooth muscle of medium and large airways→ decreased AW resistance and increased deadspace.

Answer 12

Ipratroprium (atrovent)—anticholinergic- inhaled so works directly on the airways. Albuterol + ipratroprium = combivent → 2 methods to achieve same goal.

Answer 13

Biliary/ureteral relaxation, mydriasis/cycloplegia (dilate pupils), gastric acid cessation (GERD), motion induced N/V prevention (scopolamine patch- put on night before sx because long duration and onset)

Answer 14

Too much anticholinergic Symptoms: restlessness/hallucinations, somnolence/ unconsciousness Treatment: physostigmine- crosses BBB (tertiary amine) Who: children and elderly are most sensitive to this syndrome

Answer 15

rapid onset of Symptoms: dry mouth, blurred vision, tachycardia, increased temp, flushing, irritability Effects: seizures, coma, ventilatory paralysis (central). Treatment: physostigmine

Answer 16

TOF ratio >0.7 (up to 80% receptors still blocked) tetanus with 100 hz stimulation (50% receptors can still be blocked) grip strength (difficult to quantify) negative inspiratory pressure > 20 cmH20 (can still be 50% blocked) sustained head lift for 5 seconds (GOLD STANDARD- but 33% of receptors can still be blocked)

Answer 17

Ulnar nerve (adduct thumb), posterior tibial nerve (plantar flex big toe), peroneal nerve (dorsiflex foot), facial nerve (most closely corresponds to the vocal cords→ will stimulate the orbicularis oculi or the buccinator muscle)

Answer 18

Binds to muscle relaxant itself. Can still reverse even with no twichtes. New frontier in NDNMB reversal. Independent of Ach level in the NMJ…So….a PROFOUND block (no twitches) can be reversed. Cleared renally, but speed of reversal is independent of renal function. No need for a muscarinic antagonist. Awaiting approval from the FDA. Some evidence of anaphylactic reaction.