Drugs that act on Parasympathetic NS

Question 1

muscarinic agonists

Answer 1

PIOLCARPINE -glaucoma (oscular sm contraction)

BETHANECHOL - postoperative ileus, urinary retention, (contraction)

Question 2

cholinesterases

Answer 2

AChE - hydrolyzes ACh

BUTYLRYLCHOLINESTERASE - weaker affinity for ACh
- hydrolyzes some local anesthetics + muscle relaxants

Question 3

AChE Inhibitors

Answer 3

1. Reversible Inhibitors
   - competitive - binds to catalytic site
2. Substrate Inhibitors - carbonate esters -> stable carbamate AChE (more slowly hydrolyzed than ACh)
3. Irreversible AChE Inhibitors
   - organophosphates -> stable phosphorylated form of AChE

Question 4

AChE Substrate Inhibitors

Answer 4

PHYSOSTIGMINE: glaucoma

NEOSTIGMINE: urinary retention

Question 5

Irreversible AChE Inhibitor

Answer 5

ECHOTHIOPHATE -glaucoma

Question 6

reversible organophosphate poisoning

Answer 6

irreversible AChE can be reversed by PRALIDOXIME = interacts with inactivating phosphorylated serine in active site of enzyme = transfer of phosphate

Question 7

muscarinic antagonists

Answer 7

dilate pupil
relax ciliary muscles
relax sm in GI/urinary tract
inhibit gastric secretion

treat: chronic diarrhoea, urinary incontinence, COPD, peptic ucler

SCOPOLAMINE, ATROPINE

Question 8

problems with cholinergic drugs

Answer 8

no specific

affect somatic/CNS

Question 9

side effects of agonists/ AChE inhinitors

Answer 9

hypotension
bradycardia 
bronchoconstriction
excessive salivation 
sweating
urinary incontinence
diarrhoea

Question 10

side effects with muscarinic antagonists

Answer 10

tachycardia
urinary retention
constipation
blurred vision
dry mouth 
respiratory depression

CNS effects:
hallucinations
delirium
convulsions

Question 11

M3 antagonists

Answer 11

treat urinary incontinence
contraction of urinary sphincter muscles via symp NS

blurred vision / constipation / heat stroke

DARIFENACIN