Cholinergic Antagonist (muscarinic)

Question 1

Tertiary compound (lipid soluble and can easily penetrate the brain)

**naturally occuring alkaloid

Acts directly as competitive antagonist at muscarinic receptors

Used as anticholinergic agent to :
    Reduce salivation
    Increase heart rate
    Decrease gastric motility
    Mild bronchodilation
    Treatment of organophosphate poisoning

**overdose is treated with physostigmine

Answer 1

Atropine

Question 2

Tertiary compound (lipid soluble and can easily penetrate the brain)

**naturally occuring alkaloid

Acts directly as competitive antagonist at muscarinic receptors

Same as atropine but with more central effect
May cause mild sedation
**For motion sickness

Answer 2

Scopalamine

Question 3

Tertiary compound (lipid soluble and can easily penetrate the brain)

**synthetic esters

Acts directly as competitive antagonist at muscarinic receptors

Same as atropine

**GI application : can reduce acid secretion

Used as anticholinergic agent to :
    Reduce salivation
    Increase heart rate
    Decrease gastric motility
    Mild bronchodilation
    Treatment of organophosphate poisoning

Answer 3

Dicyclomine

Question 4

Quaternary compound (water soluble and do not easily penetrate the CNS well)

Acts directly as competitive antagonist at muscarinic receptors

Mild bronchodilator in asthma therapy and COPD

Answer 4

Ipatropium

Question 5

Quaternary compound (water soluble and do not easily penetrate the CNS well)

Acts directly as competitive antagonist at muscarinic receptors

Used as antispasmodic by decreasing gastric motility

Answer 5

Propantheline

Question 6

Quaternary compound (water soluble and do not easily penetrate the CNS well)

Acts directly as competitive antagonist at muscarinic receptors

Used as preoperative medication to reduce salivation and maintain heart rate during surgery

Answer 6

Glycopyrrolate