Cholinergic Pharmacology

Question 1

Bethanechol

Answer 1

M-Ach-R Agonist. It is used postop for patients with urinary and GI retention. It should not be used in patients who have a:
     GI obstruction 
     Asthma, 
     Peptic Ulcers
     Cardiac Insufficiency 
     Hyperthyroidism

Question 2

Botulinum Toxin A

Answer 2

This is a Clostridium (gram + Bacilli) Botulinum toxin protease that cleaves SNAP protein which blocks Ach vesicle fusion with presynaptic membrane causing paralysis. It can be used for spasms, wrinkles…

Question 3

Pilocarpine

Answer 3

M-Ach-R Agonist (non-selective) which works for open-angle glaucoma & Xerostomia (Dry Mouth). It works on contracting ciliary muscle to allow humor drainage, also causes miosis. Used for dry mouth from chemotherapy OR used diagnostic in sweat test to induce sweating

Question 4

Carbachol

Answer 4

Nonselective as NAch-R or MAch-R agonist. Given as eye drop Glaucoma to cause same MOA as Pilocarpine on Ciliary Muscle contraction.

Question 5

Methacholine

Answer 5

Challenge Test for Asthma. Aerosol that binds only M-Ach-R to cause bronchoconstriction

Question 6

Neostigmine

Answer 6

Indirect Agonist. AChE-Inhibitor
Doesnt work in CNS. It is post-op for Ileus and urinary retention Like Bethanechol (direct agonist).
Tx Myasthenia Gravis (Autoimmune destruction of muscle leads to weakness d/t Ab’s that bind/block Ach-R)

Question 7

Pyridostigmine

Answer 7

Indirect Agonist. AChE-Inhibitor
Doesnt work in CNS
Tx Myasthenia Gravis (Autoimmune destruction of muscle leads to weakness d/t Ab’s that bind/block Ach-R) = Long Acting !!!

Question 8

Donepezil

Answer 8

Indirect Agonist. AChE-Inhibitor
Treats Alzheimer’s by increasing Ach
Crosses BBB

Question 9

Atropine

Answer 9

M-Ach-R Blocker Used in Organophosphate Poisoning. 
Used to cause Mydriasis, 
    dilation of eye
Tx for Bradycardia in ACLS 
    Management
"Blocks DUMBBELSS"
  - Parasympathetic Responses:
     Diarrhea
     Urination
     Miosis
     Bradycardia
     Bronchospasm
     Excitation of CNS/Skeletal 
         Muscle
     Sweating
     Salivation
Toxicity = Increased body temp due to decreased sweating, rapid pulse, dry mouth, constipation, disorientation, urinary retention in men with BPH, flushed skin due to vasodilation. Side Effect Mneumonic (Sympathetic effects)
  Hot as a hare
  Dry as a bone
  Red as a beet
  Blind as a bat
  Mad as a hatter

Question 10

Benzatropine

Answer 10

M-Ach-R Blocker. Treats Parkinson Motor Sx. Works on the CNS to improve Tremor

Question 11

Scopolamine

Answer 11

M1-Ach-R Blocker treats motion sickness and post-op N/V d/t effects on CNS and Enteric NS.

Question 12

Ipatropium

Answer 12

Inhaled M-Ach-R Blocker that causes Bronchodilation and reduces secretions. Tx for Asthma and COPD

Question 13

Oxybutinin

Answer 13

M-Ach-R Blocker that works on bladder detrusor muscle. Causes relaxation to Tx Bladder Urgency or Spasms.
Side Efffects = Sympathetic Effects

Question 14

Glycopyrrolate

Answer 14

This is an inhaler used pre-op to decrease Airway Secretions. It also is a Tx for Asthma and COPD, and decreases Acid Production so is used for Peptic Ulcers

Question 15

Edrophonium

Answer 15

Indirect Agonist. AChE-Inhibitor.
Diagnositic Test for Myasthenia Gravis. Very Short acting
Makes muscle weakness improve. If its another disease like Lambert Eaton (cant release enough Ach from Presynapse d/t Ca2+ Channel autoimmune attack) and Cholinergic Crisis it makes it worse causing a depolarizing block

Question 16

Physostigmine

Answer 16

Indirect Agonist. AChE-Inhibitor.
Used for Anti-Cholinergic Toxicity for those that cross the BBB. Increases Ach to combat effects of Anti-cholinergics like Atropine Overdose

Question 17

Organophosphates Poisoning of the AChE

Answer 17

Irreversibly inhibits the ACh-E, causes enhanced parasympathetic activity = Diarrhea, Urination, Miosis, Bronchospasm, Bradycardia, Skeletal Muscle excitation, CNS Excitation, Lacrimation, Sweating, Salivation.

Antidote = Atropine (M-ACh-R Blocker) + Pralidoxime

Question 18

Pralidoximine

Answer 18

Binds different part of AChE poisoned by Organphosphates and causing it to release and join the drug and restore function of the Enzyme AchE