Cholinergic Agents 1

Dimethylphenylpiperazinium-(DMPP) Cholinergic Agents Alkaloids Nicotine Lobeline Arecoline Muscarine Pilocarpine Synthetic Agents Dimethylphenylpiperazinium-(DMPP) Oxotremorine Methacholine Bethanechol Carbachol Cevimeline 2

Cell body of the postsynaptic neurons 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 3

Muscarine Clitocybe sp: content of muscarine is high 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 4

Has muscarinic actions Used for xerostomia Used for glaucoma Pilocarpine Has muscarinic actions Used for xerostomia Used for glaucoma 5

Structure of Acetylcholine and its Derivatives Methacholine Bethanechol Carbachol 6

Therapeutic Uses of Cholinergic Agonists Dentistry Pilocarpine Cevimeline Ophthalmology Carbachol Gastrointestinal tract Bethanechol Urinary bladder 7

Contraindications to the Use of Choline Esters Hyperthyroidism Asthma Coronary insufficiency Peptic ulcer Organic obstruction in bladder or gastrointestinal tract 8

Toxicity of Choline Esters Flushing SWEATING (diaphoresis) Abdominal cramps Spasm of the urinary bladder Spasm of accomodation Miosis Headache Salivation Bronchospasm Lacrimation Hypotension Bradycardia 9

Agents That Inhibit Acetylcholinesterase 10

Acetylcholinesterase (True Cholinesterase) 11