ANS

Question 1

Acetylcholine

Muscarinic actions

Answer 1

1. CVS :
   a. Heart - decreased HR, FOC, A-V conduction
   b. Blood vessels- vasodilation > hypotension
2. Smooth muscles
   a. GI Tract : increased tone, peristalsis, secretions. May cause defecation.
   b. Urinary bladder :
   Contacts - detrusor
   Relaxes- trigone and spinchter. May cause urination.
   c. Bronchi : bronchospasm, increased tracheobronchial secretions.
3. Exocrine glands : increased secretions
4. Eye - no effect

Question 2

Classification of cholinergics

Answer 2

Directly acting:
Choline esters : acetylcholine
Alkaloids: pilocarpine, muscarine

Indirectly acting (anticholinesterases):
Reversible : physostigmine, neostigmine, pyridostigmine, edrophonium
Irreversible: parathion, malathion, sarin, dyflos.

Question 3

Pilocarpine

Uses

Answer 3

1. In treatment of open angle glaucoma, acute congestive glaucoma.
   Causes miosis, increases tone of ciliary muscle, open trabecular meshwork, reduces IOP.
2. Used alternatively with mydriatics to break down adhesions between iris and lens.
3. Used to reverse pupillary dilatation.
4. Used as a sialagogue.

Question 4

Therapeutic uses of reversible anticholinesterases
Physostigmine
Neostigmine

Answer 4

1. Eye: glaucoma, reverse pupillary dilatation, tp break adhesion between iris and lens.
2. Myasthenia gravis
3. Post urinary retention, paralytic ileus.
4. Curare poisoning
5. Atropine poisoning
6. Alzheimer’s disease.

Question 5

Anticholinergic
Antimuscarinic
Classification

Answer 5

1. Natural alkaloids - Atropine, scopolamine.
2. a. Mydriatics - homatropine, tropicamide.
   b. COPD, asthma - ipratromium bromide.
   c. Peptic ulcer - pirenzepine, clinidium, propantheline.
   d. Antispasmodic- flavoxate, dicyclomine, darifenacin.
   e. Preanaesthetic - glycopyrrolate
   f. Parkinsonism - benzhexol, benztropine, biperiden.

Question 6

Atropine

Pharmacological actions

Answer 6

1. CNS - reduces cholinergic over activity in basal ganglia. Suppresses vestibular disturbances, antimotion sickness effect.
2. CVS - low doses: initial bradycardia (m1 blockade), therapeutic doses: tachycardia ( m2 blockade). High doses : flushing, hypotension.
3. Glands - cholinergic secretions are reduced (m3 blockade) , skin and mucous membranes become dry.
4. Eye - passive mydriasis, cycloplegia.
5. Smooth muscles:
   a. GIT- decreases tone and motility.
   b. Urinary bladder - increases tone of trigone and spinchter.
   c. Bronchi - relaxes muscles, reduces secretion , mucociliary clearance.

Question 7

Atropine and substitutesTherapeutic uses

Answer 7

1. Ophthalmic uses
2. Pre anaesthesic medication
3. Sialorrhoea
4. COPD and brochial asthma
5. Antispasmodics
6. Urinary disorders
7. Poisoning
8. Vagolytic
9. Parkinsonism

Question 8

Scopalamine

Hyoscine

Answer 8

1. Produces all actions of atropine.
2. Produces prominent CNS depression with sedation and amnesia.
3. Has shorter duration of action than atropine.
4. Suppresses vestibular disturbances and prevents motion sickness.
5. DOC for motion sickness.
   Causes sedation and dryness of mouth.