Myasthenia Gravis Pharm (Exam 2) Flashcards
neostigmine: class
Cholinesterase Inhibitor
neostigmine: Indication
MG
neostigmine: MOA
Neostigmine is a parasympathomimetic reversible cholinesterase inhibitor
The drug inhibits acetylcholinesterase which is responsible for degradation of ACH
More ACH is present by interfering with breakdown of ACH
Allows for more muscle contraction
neostigmine effects both
muscarinic and nicotinic receptors
Nicotinic Receptors are located
Skeletal muscle
Blood vessels
Adrenal
Muscarinic receptors are located
Glands
Sweat
neostigmine: Adverse Effects (Muscarinic)
Increased Secretions (GI)
Urinary urgency
Bradycardia
Bronchial Constriction
Miosis (near sightnedness)
Neostigmine: Adverse Effects (Nicotinic)
Therapeutic Doses = Increased Muscle contraction
Toxic doses = Reduced Contraction (overstimulation of muscle)
Toxic dose can lead to cholinergic crisis
neostigmine: Cholinergic Crisis
Extreme Muscle Weakness or Paralysis
Excessive Muscarinic Stimulation (Diarrhea-Cramping-Bradycardia)
Treatment of cholinergic crisis
Mechanical ventilation
ATROPINE (anticholinergic)
Patient should wear med-aleart bracelet at all time
Antidote for cholinergic crisis
Atropine
How to tell difference between MG and Cholinergic Crisis
Give EDROPHONIUM:
-short acting cholinesterase inhibitor
-increases acetylcholine temporarily
If they are in a MG crisis they will improve because there is an increase in acetylcholine
If they are in a cholinergic crisis they will worsen because they already have too much acetylcholine
MS crisis vs Cholinergic Crisis
MG Crisis:
-Not enough stimulation or acetylcholine
-Muscles are not stimulate and are weak
-Respiratory failure
Cholinergic Crisis:
-Too much acetylcholine or neostigmine
-Overstimulation of muscles and muscles are worn out
-Leading to respiratory failure
Main anticholinergic
Atropine
Cholinergics vs Anticholinergics: GI tract
Cholinergic: Increase motility
Anticholinergic: Decrease motility
Cholinergics vs Anticholinergics: Mouth
Cholinergic: Increased secretions
Anticholinergic: Dry mouth
Cholinergics vs Anticholinergics: Bladder
Cholengeric: Urinary Urgency
Anticholinergic: Urinary Retention
Cholinergics vs Anticholinergics: Heart
Cholinergic: Bradycardia
Anticholinergic: Tachycardia
Cholinergics vs Anticholinergics: Lungs
Cholinergic: Bronchial constriction
Anticholinergic: Bronchial dilation
Cholinergics vs Anticholinergics: Eyes
Cholinergic: Misos (constriction)
Cholinergic: Mydriasis (dilation)
Cholinergic Crisis Occurs from
Cholinesterase Inhibitor Overdose
TOO much ACH
