Cholinergic Agents

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Cholinergic Agents
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Cholinergic Agents
Alkaloids Nicotine Lobeline Arecoline Muscarine Pi
locarpine
Synthetic Agents Dimethylphenylpiperazinium-(DMPP)
Oxotremorine Methacholine Bethanechol Carbachol C
evimeline
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Nicotine

• Nicotine mimics the actions of acetylcholine at
  nicotinic sites
• Cell body of the postsynaptic neurons
• sympathetic and parasympathetic divisions
• Chromaffin cells of the adrenal medulla
• End plate of skeletal muscle fiber
• Affinity for NN sites versus NM sites
• Used as an insecticide

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Muscarine

• Muscarine mimics the actions of acetylcholine at
  smooth muscles, cardiac muscles, and glands
• Poisoning by muscarine produces intense effects
  qualitative to those produced by cholinergic
  stimulation of smooth muscles, cardiac muscle,
  and glands
• Muscarine is found in various mushrooms
• Amanita muscaria content of muscarine is very
  low
• Inocybe sp content of muscarine is high
• Clitocybe sp content of muscarine is high

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Pilocarpine

• Has muscarinic actions
• Used for xerostomia
• Used for glaucoma

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Structure of Acetylcholine and its Derivatives
Acetylcholine
Methacholine
Bethanechol
Carbachol
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Therapeutic Uses of Cholinergic Agonists

• Dentistry
• Pilocarpine
• Cevimeline
• Ophthalmology
• Pilocarpine
• Carbachol
• Gastrointestinal tract
• Bethanechol
• Urinary bladder
• Bethanechol

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Contraindications to the Use of Choline Esters

• Hyperthyroidism
• Asthma
• Coronary insufficiency
• Peptic ulcer
• Organic obstruction in bladder or
  gastrointestinal tract

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Toxicity of Choline Esters

• Flushing
• SWEATING (diaphoresis)
• Abdominal cramps
• Spasm of the urinary bladder
• Spasm of accomodation
• Miosis
• Headache
• Salivation
• Bronchospasm
• Lacrimation
• Hypotension
• Bradycardia

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Agents That Inhibit Acetylcholinesterase
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Acetylcholinesterase
(True Cholinesterase)