Chapter 7-8: Cholinoceptor Drugs Flashcards
Test 2
Where are mAch-R?
Nerves
Heart/smooth muscle
Glands/endothelium
Where are nAch-R?
NMJ
Autonomic ganglion
Muscarine mimics effects of what NS?
PNS
What can bind to the cholinoceptors?
Choline esters and Alkaloids
What is Mycetism?
Toxicity of Muscarinic agonism
Brightly colored mushrooms
Vomiting, diarrhea, drooling, decreased HR/RR/BP, shock
What is Tx for Mycetism?
Antimuscarinic:
2mg Atropine
T/F: Nicotine only binds to nAch-R?
T
Why do you see tremors when smoking?
Nicotine at the NMJ binds to the nAch-R causing small contractions
What does the M1,3,5 receptors do?
Stimulatory
Increase phospholipase C
What does M2,4 receptors do?
Inhibitory
inhibits adenylyl cyclase
List the major clinical uses of cholinomimetic agonists
- Tx of Glaucoma: Carbachol/pilocarpine - reduce intraocular pressure with glaucoma
- MG: neostigmine/pyridostigmine- improve muscle strength by increasing acetylcholine levels at NMJ
-Alzheimer’s: Cholinesterase INHIBITOR donepezil - manage symptoms by enhancing cholinergic function in the brain
-Postoperative Ileus and Urinary Retention: Bethanechol- stimulate bowel and bladder function
-Xerostomia (Dry Mouth): Pilocarpine and cevimeline- stimulate salivary secretion in patients with dry mouth, often due to Sjögren’s syndrome or radiation therapy.
Tx of Glaucoma
Carbachol/pilocarpine
Management of MG:
-stigmine
Management of Alzheimers
donepezil
Postoperative Ileus and Urinary Retention Tx
Bethanechol
Dry mouth Tx:
“Xerostomia”
Pilocarpine
cevimeline
T/F: Esters of Choline cross barriers easily
F
Large and charged. insoluble in lipids and doesnt cross barriers easily
Describe the Pharmacokinetics for Esters of Choline
A: poor
D: poor
M: -Ach: rapid (5-20 secs)
- Methacholine: 3x longer
- Carbachol/Bethanechol - resistant to hydrolysis: 4 min to hours
What is the Betel nut?
Arecoline Alkaloid
similar effects to nicotine
used alot in various places in the world and has a red color
Nicotine is very ____ soluble
lipid
Nicotine stimulates _______ NS
ALL OF THE
Which NS responses dominate the others in response to nicotine?
Sympathetic
Describe Pharmacokinetics with Alkaloids
A: Pilocarpine, Nicotine, Lobeline
(-INE)!!!!!!!!! - well
-Muscarine - charged so less well
E: Kidneys- enhanced by acidification of urine
T/F: Atropine in Open Angle glaucoma is contraindicated and is a medical emergency
F
Closed-angle (Narrow angle)
What is glaucoma?
excess intraocular fluid
cholinomimetics Organ effects: Eye
Constriction of pupil “miosis”
Increases intraocular drainage
cholinomimetics Organ effects: CVS
-Reduction in peripheral vascular resistance
-vasodilation
-decrease BP
-reflex tachycardia
large doses bradycardia
cholinomimetics Organ effects: Respiratory
bronchials contract
secretions increased
cholinomimetics Organ effects: GI
Increased GI activity
relaxed sphincter
cholinomimetics Organ effects: CNS
release dopamine, serotonin, GABA, NE
enhance cognitive functions
Define the different types of glaucoma and the use of cholinomimetics
Open angled: cholinomimetic drugs like pilocarpine can constrict the pupil and increase drainage through the canal of Schlemm.
Closed angled: the iris is pushed forward, cholinomimetics can worsen the condition by further constricting the angle and impeding drainage. This can lead to a medical emergency.
cholinomimetics Organ effects: NMJ
immediate depolarization of end plate
muscle contraction
What is depolarization blockade?
When the cell is continuously being depolarized and cant repolarize causing flaccid paralysis
Ex) Succs
