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Parasympathetic Activation Clinical Effects
- -Nonvascular SM contraction
- -Increase intestinal motility (GI/abdominal cramps)
- -Increase bladder motility (urinary incontinence)
- -Increase bronchiolar & alveolar contraction (shortness of breath)
- -Contraction of ciliary eye muscle (constricted pupil)
- -Increase exocrine gland secretion (sweat, tears, saliva)
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Choline esters
-Bethanechol (Urecholine)
-Carbachol (Isopto-Carbachol)
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Direct Acting Cholinergic Agonists (sub-classes)
- -Choline Esters
- -Alkaloids
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Bethanecol (Urecholine)
- Type: Choline ester; (Cholinergic Agonist)
- Route: SQ, PO
- Tx for: prolonged urinary retention
Note: "usually in response to anesthesia, but not really; if anatomical problem, don't use b/c can rupture bladder"
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Carbachol (Isopto-Carbachol)
- Type: Choline ester; (Cholinergic Agonist)
- Route: ophthalmic (Top?)
- Tx for: glaucoma
Note: DON'T use cholinergic blocker (anticholinergic) for glaucoma
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Alkaloids
-Nicotine
-Pilocarpine
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Nicotine
- Type: Alkaloid cholinergic agonist
- Route: patch (top); PO, spray; No chew b/c bad AEs
- Tx for: quit smoking
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Pilocarpine
- Type: Alkaloid cholinergic agonist
- Route: opthalmic (top)
- Tx for: glaucoma
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Indirect Cholinomimetics (=agonist)
Mechanism of action = cholinesterase inhibitors
Reversible vs. Irreversible types
Strong parasympathetic action
NMJ for skeletal muscle (independent from parasympathetic action)
Clinical uses: Myasthenia gravis, glaucoma
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Pyridostigmine (Mestinon)
Reversible indirect-acting, cholinergic agonist
Tx: Myasthenia gravis
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Physostigmine
Reversible, Indirect-Acting, Cholinergic agonist
Tx: Myasthenia gravis
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Neostigmine
Reversible, Indirect-Acting, Cholinergic agonist
Tx: reverse neuromuscular blockade used in anesthesia
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Edrophonium
Reversible, Indirect-Acting, Cholinergic agonist
Tx: diagnostic tol for Myasthenia gravis
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Organosphosphates (Malathion)
IRREVERSIBLE, Indirect-Acting, Cholinergic agonist
pesticide in agriculature; prone to accidental poisoning
- Note: use Pralidoxime to help counteract effects by regenerating cholinesterase
- troops get syringe of atropine + pralidoxime for chem warfare
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Anticholinergic (cholinoreceptor blockers) Clinical Effects
- -Decreased contraction of non-vascular SM
- -Contraction of sphincters
- -Decrease in exocrine gland secretions
- -Relaxation of ciliary eye muscle
- = constipation, dry mouth, dilated pupils/blurry vision, urinary retention
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