Anticholinergic Agents/Muscarinic Antagonists Flashcards
Muscarinic antagonist mechanism of action
Competitive inhibitors of Ach at parasympathetic muscarinic receptors to increase the heart rate
muscarinic antagonist overall effects
Inhibits salivary, bronchial, and GI secretions
Reduces gastric motility
Causes bronchodilation
Muscarinic antagoists antagonize the ______ effects of ________ used to reverse NDMR
muscarinic; anticholinesterases
atropine mechanism of action
Competitive acetylcholine antagonist at central and peripheral receptors, antimuscarinic, naturally occurring alkaloid
atropine structure
Tertiary amine
atropine cautions
careful use in narrow-angle glaucoma
atropine indications
reversal, brady arrhythmias/vagal stimulation, oculocardia reflex, peritoneal stimulation
atropine OB effects
Crosses placenta to increase FHR and decrease beat -to- beat variability in baby
atropine dose
0.014 mg per mg of edrophonium
.2-.4mg for vagal stimulation
atropine onset and duration
onset: < 1 min
duration: up to 30 min
glycopyrrolate mechanism
Synthetic antimuscarinic, competitive Ach antagonist
glycopyrrolate uses
in combo with Neostigmine for reversal, antisialogogue(xerostomia), increase HR
glycopyrrolate structure
quaternary ammonium
glycopyrrolate dose
0.2 mg per 1 mg Neostigmine
glycopyrrolate onset
about 1 min IV; 15-30 min IM
glycopyrrolate duration
2-4 hours
does glycopyrrolate cause CNS effects or mydriasis
no
scopolamine mechanism
Competitive antagonist of Ach at muscarinic receptors, antagonizes histamine and serotonin
scopolamine uses
Decreases secretions, PONV, motion sickness/vertigo, dilate pupils and cycloplegia, unstable trauma pt, sedation/amnesia
scopolamine in elderly
toxic psychosis
scopolamine side effects
Effects from restlessness to agitation
how can scopolamine be administered before surgery
IM or IV
scopolamine typical dose
0.3-0.5 mg IM or IV
cycloplegia
seen in scopolamine; paralyzing the ciliary muscle
central anticholinergic syndrome
Overdose of scopolamine and sometimes Atropine(tertiary amines), phenothiazine
central anticholinergic syndrome signs
anxiety, disoriented, hyperactive, sedation, seizure, mydriasis, increased HR, Atropine flush, dry/flushed skin, atropine fever
Can be mistaken for delayed recovery
how to treat central anticholinergic syndrome
Treat with Benzos
Physostigmine: tertiary amine that crosses the BBB
physostigmine dose
1-2 mg IV and may need to be repeated every 1-2 hours (physostigmine is metabolized rapidly)
