Cholinergic Receptors and Agents Acting at the Neuromuscular Junction Flashcards
Where is the site of action of vesamicol?
Storage; Vesamicol blocks Ach transport into their vesicles blocking their storage
Where is the site of action of Mg2+?
Release; Mg2+ competes with Ca2+ and does not allow the vesicle to release its Ach
Where is the site of action of b-bungarotoxin?
Release; b-bungarotoxin blocks pre-synaptic release of neurotransmitters.
Where is the site of action of rivastigmine?
Degradation; Revastigmine is a cholinesterase inhibitor that inhibits both butyrlcholinesterase and acetylcholinesterase.
Where is the site of action of atracurium?
Receptor; Atracurium antagonizes the action of Ach by binding competitively with cholinergic receptor sites on motor end-plates.
Where is the site of action of trimetaphan?
Receptor; Trimetaphan is a ganglionic block agent by competing with Ach for post-synaptic receptor sites.
Where is the site of action of edrophonium?
Degradation; Edrophonium prolongs the action of Ach by inhibiting the action of acetylcholinesterase.
What kind of receptors does acetylcholine activates?
Ionotropic and Metabotropic Receptors
Where is the site of action of a-bungarotoxin?
Receptor; a-bungarotoxin blocks post-synaptic neuromuscular nicotinic receptor.
Where is the site of action of pyridostigmine?
Degradation; Pyridostigmine is an acetylcholinesterase inhibitor.
Where is the site of action of bethanechol?
Receptor; Bethanechol is a direct acting agonist of muscarinic receptor promoting micturition.
Which drug is a centrally acting cholinesterase inhibitor used in the treatment of Alzheimer’s type of dementia?
Rivastigmine
What is the rate limiting step in the synthesis of acetylcholine?
Active transport of choline into the cell
A patient is rushed to the emergency room after ingesting an unkown substance. On examination, the patient was restlesss, had mitotic pupils, excessive salivation and lacrimation and wheezes were noted on auscultation of the lungs. Which most likely was the ingested drug?
Organophosphates
True or false, pralidoxime splits the phosphorylated covalent bond if given early in organophosphate poisoning?
True
True or false, large doses of cholinesterase inhibitors have no effect on the autonomic ganglia?
False
True or false, depolarizing and non-depolarizing drugs have a structural resemblance to acetylecholine?
True
True or false, non-deplozarizing drugs have no effect on the autonomic ganglia?
False
True or false, tetanic stimulation relieves neuromuscular blockade in phase I depolarizing block?
False
A patient who has renal insufficiency is ti undergo surgery for removal of renal cyst. Which neurotransmitter blocker is safest to use?
Atracurium
Which drug acting on the autonomic ganglia is used to clinically treat hypertension?
Trimetaphan
Which drug is responsible for block the transport of acetylcholine and forms a false neurotransmitter?
Triethylcholine
Atropine causes?
Cycloplegia, Dry Mouth and Mydriasis
Where is the site of action of ecothiopate?
Degradation; Ecothiopate is an anti-cholinesterase inhibitor.
