parasympathetic NS drugs

Question 1

Carbachol

Answer 1

treatment for glaucoma acting as a direct agonist of muscarinic receptors

Question 2

Atropine

Answer 2

anti-arrhythmic direct antagonist of M receptors, specific treatment for bradycardia

Question 3

hyoscine

Answer 3

direct antagonist suppresses secretion and used to treat motion sickness

Question 4

Pilocarpin

Answer 4

M3 receptor agonist (pupil constriction (miosis) and increased aqueous humor outflow) and nic antagonist

treatment for glaucoma and dry mouth

Question 5

Ipratropium

Answer 5

M2 and M3 antagonists for bronchodilation, used to treat asthma, COPD and bronchitis

however reduced Ca2+ as blocks blocks M3 in lungs and presynaptic M2, increasing ACh in the synapse so could be out competed on M3

Question 6

Why is it better to use tiotropium than ipratropium

Answer 6

only selectively binds to M3 on lungs causing bronchodilation as less Ca2+ released by IP3, and no increased synaptic Ach as M2 is still active