Cholinergic Agonists

Bethanachol MOA

Direct muscarinic agonist —> stimulates smooth muscle contraction in bladder

Which drugs are the direct muscarinic agonists?

Bethanechol, Pilocarpine

Which drugs are the AChE inhibitors

Edrophonium (short)

Donepezil (CNS)

Pralidoxime (reactivator of poisoning)

What is the primary indication of Bethanechol?

Urinary retention

What are side effects of Bethanechol?

Cholinergic side effects = increase of parasympathetic effects (salivation, sweating, diarrhea, bronchospasm, bradycardia)

What is the MOA of Pilocarpine

Direct muscarinic agonist at muscarinic receptor in the eye & salivary glands:

increase secretions → contract ciliary muscle

What’s the primary indication of Pilocarpine

1. Treats glaucoma

2. Used as treatment for dry mouth

What are the side effects of Pilocarpine

Cholinergic effects (salivation, urination urgency, diarrhea, miosis -pupil constriction, bradycardia, bronchoconstriction, decrease atrioventricular conduction, increase motility)

What’s the MOA for Edrophonium

Acetylcholinesterase inhibitor acting on the skeletal muscle = prevent break down of ACh → increases ACh at NMJ to act on open receptors —> muscle contraction

What is the primary indication of Edrophonium

1.Treatment for myasthenia gravis (used as a diagnostic test for this disease)

2. Used as a reversal agent for non-depolarizing neuromuscular blockers

What are the side effects of Edrophonium?

Cholinergic side effects when given too much → too much ACh around

(urination urgency, salivation, bradycardia, more secretions, bronchospasm, miosis - pupil constriction, increased motility, diarrhea)

What is the MOA of Pralidoxime?

Cholinesterase reactivator: breaks organophosphate enzyme & acetylcholinesterase bond during organophosphate poisoning

What is the primary indication of Pralidoxime?

Organophosphate poisoning

What is the MOA of Donepezil

Reversible acetylcholinesterase inhibitor acting in CNS (crosses Blood, brain, barrier)

What’s the primary indication of Donepezil

Alzheimer’s disease

What’s the side effects of Donepezil

Cholinergic side effects (urination urgency, bradycardia, diarrhea, bronchoconstriction, secretions, salivation, increase motility to digest)