12.2 Cholinergic and Anticholinergic Flashcards
1
Q
Cholinergic Receptors
A
- Parasympathetic receptors activated by binding to acetylcholine (neurotransmitter)
2
Q
Acetylcholine Functions
A
- Neurotransmitter
Brain - Memory storage and retrieval
GI Tract - Promotes normal secretory/motor activity
Urinary Tract - Muscle contraction/relaxation to facilitate urination
3
Q
Cholinergic Drugs
A
- Mimic or block actions of acetylcholine
- Can also prevent breakdown of acetylcholine (cholinesterase inhibitors)
4
Q
Cholinergic Receptor Types
A
Nicotinic - Responsive agonist to nicotine
Muscarinic - Responsive agonist to muscarine
5
Q
Nicotinic Receptors
A
- Nicotine selectively binds to nicotinic receptors
- Antagonist block transmission at the synapse of autonomic ganglia, skeletal neuromuscular junction, and CNS nicotinic synapses
- They are also called (Ganglionic Blockers)
- Blocking the receptors produce anticholinergic effects.
- Triggers rapid neural and neuromuscular transmission
6
Q
Muscarinic Receptors
A
- Slows heart rate, contraction of smooth muscle, increase secretion from exocrine glandular tissue (salivary, gastric acid, airway mucosal glands).
- Antagonist (anticholinergics) produce mydriasis and bronchodilation, increase heart rate, inhibit secretions.
7
Q
Effects of Direct Acting Cholinergics
A
- Decreased HR, Vasodilation, BP
- Increased GI, Urinary Bladder, Bronchial Smooth Muscle tone and contractility
- Increased Salivary, GI, Respiratory secretions
- GI and Urinary Sphincter relaxation
- Pupil constriction and ciliary contraction (accommodates near sightedness)
8
Q
Bethanechol (Urecholine) - Urinary Retention
A
- Treats urinary retention
- Stimulates muscarinic receptors (no affect on nicotinic)
- Increases tone of detrusor muscle for bladder and gastric tone motility to urinate and defecate
- Poorly absorbed in GI tract (30-90 min)
- SubQ Onset (5-15 min)
Adverse Effects - Flushing, Watery Eyes, Increased Saliva/Urination, Dizziness, Headache, Lightheadedness
Contraindications - Obstructions, Inflammatory Bowel Disease, Peritonitis, Recent Bladder/GI Surgery
Antidote - Atropine Sulfate
9
Q
Myasthenia Gravis
A
- Cholinesterase Inhibitor (Neostigmine, physostigmine)
- (ChEI) Prevent breakdown of acetylcholine. Increases amount of acetylcholine in synaptic cleft.
- Improves skeletal muscle and strength.
10
Q
Neostigmine (Prostigmin) - Cholinesterase Inhibitor
A
- Treatment of myasthenia gravis
(Autoimmune disorder, antibodies destroy communication between nerves and muscle) - Reverses affects of muscle relaxants such as tubocurarine and pancuronium.
- Does not cross BBB
11
Q
Neostigmine
A
- Poorly absorbed in GI Tract from Oral Administration
Adverse Effects - Excessive salivation, increased gastric secretions, increased GI tone and motility, urinary urgency, bradycardia, sweating, polarizing neuromuscular blockage and respiratory depression
Contraindications - Hypersensitivity and peritonitis or obstruction to GI tract and urinary tract
- IV, IM, SC
ANTIDOTE - Atropine
12
Q
Myasthenia Gravis
A
- Autoimmune disorder that affects neuromuscular junction and reduces acetylcholine receptors.
- Muscle weakness, hypoventilation, inability to cough effectively.
- Take with food or milk to reduce gastric distress/ulceration.
13
Q
Edrophonium (Tensilon)
A
- Used to diagnose Myasthenia Gravis not treat
- Effects only last an hour
- 2-4 mg IV
- Can cause bronchospasm, excess bronchial secretions, GI problems.
14
Q
Alzheimer’s Disease
A
- Cholinesterase Inhibitor (Donepezil, tacrine)
- Enhances transmissions by central cholinergic neurons that haven’t been destroyed
- Slows disease progression
- For patients with mild to moderate AD
- Improvements are modest and short term
15
Q
Glaucoma
A
Cholinergic (Miotic)
- Reduce eye pressure by increasing drainage of intraocular fluid.
- Can be used alone or with other glaucoma medication
