Pharmacology Midterm- Autonomic Drugs

Front 1

Bethanechol

Classification
Treatment
Action

Back 1

cholinoceptor agonist –muscarinic
↑ GIT motility
GIT, urinary bladder

Front 2

Pilocarpine
Classification
Route
Treatment
Action

Back 2

cholinoceptor agonist – muscarinic
ophthalmic/local in to conjunctival sac
glaucoma, prevent synechiation (adhesion between iris and cornea or lens)
miosis, decreases aqueous humor

Front 3

Physostigmine
Classification
Route
Treatment
Action

Back 3

cholinesterase inhibitor (reversible)
ophthalmic/local
Glaucoma
miosis, lens (focus)

Front 4

Neostigmine
Classification
Route
Treatment
Action

Back 4

cholinesterase inhibitor (reversible)
SQ, *slow IV*
smooth muscle atony (GIT, urinary bladder)
reverses skeletal muscle paralysis as neuromuscular antagonist

Front 5

Atropine
Classification
Route
Treatment

Back 5

muscarinic cholinoceptor
antagonist
SQ, IV
anesthetic pre-med., ophthalmic

Front 6

What is the action of atropine?

Back 6

↓ salivation and bronchial secretion;
↑ broncho-dilation and heart rate;
Mydriasis (dilation of pupil) and cycloplegia (weak contraction of ciliary muscles)

Front 7

phenylephrine
Classification
Route
Treatmen

Back 7

alpha adrenoceptor agonist
PO, IV, local/ophthalmic
hypotension, decongestion, ophthal. (dogs)

Front 8

What is the action of phenylephrine?

Back 8

mydriasis in dogs, hypertension, vagal stimulation (bradycardia), vasoconstriction, increased BP

Front 9

Explain why acetylcholine does not have a therapeutic indication ?

Back 9

•No selectivity Ach works on many tissues simultaneously and has varied effects because it is a mixed cholinoceptor (muscarinic/nicotinic)
• Brief duration of action due to rapid hydrolysis (it’s inactivated by cholinesterase)

Front 10

To what are the pharmacological effects produced by cholinesterase inhibitors attributed?

Back 10

Inhibit enzyme  ↑ endogenous Ach  ↑ action at all cholinoceptors with prolonged effects

Front 11

Why do the effects produced by organophosphorus compounds persist for a long duration ?

Back 11

•irreversible AchE (acetylcholinesterase) inhibitor
•highly stable
•well absorbed by all routes
•wide distribution to all body parts/systems, especially CNS
•prolonged action due to “ageing”, which strengthens phosphorus-enzyme bond

Front 12

Name the antidote that will suppress the muscarinic effects produced by organophosphorus compounds?

Back 12

•Repeated high IV doses of atropine will combat muscarinic effects and CNS effects of Ach
•Oximes regenerate AchE by displacing the phosphate group  give repeated doses slow IV
•Pralidoxime (regenerates AchE) given with ↑dose of atropine (to competitively block Ach effects) provides antidotal therapy of organophosphate toxicity.