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14 Cards in this Set
- Front
- Back
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What are the 8 major effects of the PSNS?
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Decreased heart rate (bradycardia)
Bronchoconstriction GIT smooth muscle contraction Micturition Miosis (constriction of pupil) and cycloplegia (loss of accomodation of lens- convex shape) Increased bronchial secretions Increased salivation Erection |
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What are nicotinic receptors?
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Cation selective ion channels
Found on the postganlionic membrane in all ganglia of the ANS. Different types of nicotinic receptors located in skeletal muscle and the nervous system |
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What are muscarinic receptors?
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7 transmembrane G-protein coupled receptor
M1 - M5 Inhibits adenyl cyclase (therefore decreases cAMP) |
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Name me 3 cholinomimetics that are choline esters.
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1) Cholines esters
Acetylcholine, Carbachol, Bethanecol, Methacholine Poorly absorbed and poorly distributed in the CNS (hydrophilic) Variable susceptibility to acetylcholinesterase |
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Name me 3 cholinomimetics agonists that are alcoloids and muscarinic.
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2) Alkaloids (and synthetic analogs)
Those with actions chiefly muscarinic include Muscarine, Pilocarpine, Oxotremorine Those with actions primarily nicotinic include Nicotine, Lobeline, DMPP Well absorbed from most sites of administration Excretion mainly by the kidneys Some used primarily for research purposes DMPP - selective stimulation of ganglia |
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Name me the Ache inhibitors that is also a quartenary alcohol and two carbamates, and phosphoric acid esters.
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Name me the Ache inhibitors that is also a quartenary alcohol and two carbamates, and phosphoric acid esters.
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Bethanecol, Neostigmine
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Postoperative and neurogenic ileus
Urinary retention Activates bowel and bladder smooth muscle |
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Carbachol, Pilocarpine,
Physostigmine Echothiophate |
Glaucoma
Activates pupillary sphincter and ciliary muscles of the eye to cause miosis |
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Edrophonium
Neostigmine/ pyridostigmine |
Diagnosis and treatment of myasthenia gravis
Prolong and intensify actions of physiologically released ACh |
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What are DUMBBELS?
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Accidental (or deliberate) exposure to toxic amounts of pesticides, insecticides and anthelmintics
Parathion - rapidly fatal Malathion - safer in mammals as metabolized rapidly to inactive products CNS stimulation, DUMBBELS (diarrhoea, urination, miosis, bradycardia, bronchoconstriction, emesis, lacrimation, salivation) and excitation of skeletal muscle, |
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Q how would you treat OP poisoning. ?
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Metaldehyde vs. Carbamate snail baits in small animals
only carbamates can be reversed Atropine as a treatment for cholinergic poisoning - muscarinic receptor antagonist |
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Name the drug that is an antagonists at the muscarinic receptor.
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Natural alkaloids and tertiary amines well absorbed from gut and conjunctival membranes
Widely distributed including CNS Cause sedation Quaternary compounds poorly taken up by brain 60% excreted unchanged in the urine Atropine T1/2 of 2 hours Eye effects persist 72hrs + Rabbits have atropine esterase - rapidly metabolise the drug |
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What are the uses of the antagonists at the cholinergic muscarinic receptor?
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To relieve GIT spasm eg. hyoscine (“Buscopan”)
Treatment of Parkinsons disease eg. benztropine Prevention of motion sickness eg. Scopolamine Respiratory Disorders ipratropium -inhalation drug for asthma and COPD |
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Name the toxicity accociated with muscarinic antagonists.
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“Dry as a bone, red as a beet and mad as a hatter”
Blockade of thermoregulatory sweating mechanisms - risk of hyperthermia Sweating, salivation, lacrimation all significantly reduced Risk of glaucoma due to increased ocular pressure and blurred vision Urinary retention - risk with prostatic hyperplasia Constipation CNS effects - sedation, hallucinations |
