true or false. Acetylcholine is available as a drug and used in pharmacotherapy
true
What are 2 examples of choinomimetic drugs used in dentistry to treat xerostomia?
pilocarpine (salagen)
cevimeline (evoxac)
Why aren't the cholinergic agonists pilocarpine (salagen) and cevimeline (evoxac) inactivated by acetylcholinesterase?
because they are not choline esters
What else is pilocarpine used for besides dentistry?
as eyedrops for glaucoma
drugs that do not act on cholinergic receptors, but instead inhibit the enzyme that degrades acetylcholine
antichlinesterase drugs
What is an example of an antichlinesterase drug that is useful in the treatment of myasthenia gravis?
neostigmine
group of drugs that includes agents that affect muscarinic receptor activity and drugs that affect nicotinic receptor activity
cholinergic blocking agents
What is the prototype antimuscarinic drug that blocks muscarinic receptors only and has no effect on nicotinic receptors?
atropine
What is the name of the plant that atropine comes from?
a nightshade plant called atropa belladonna
What is the action of atropine?
a competitive antagonism
true or false. Atropine has a higher affinity for the muscarinic receptor than that of acetylcholine
true
What is the action of atropine?
it binds to the receptor, preventing acetylcholine from binding, which allows tissue cholinesterase to degrade acetylcholine before it can bind to muscarinic receptors
What is an example of when atropine has been used in dentistry?
prior to making a dental impression when a dry field is needed
What is the mnemonic that describes the effects of toxic doses of atropine?
dry as a bone (decreased sweating)
hot as a hare (increased body temp)
blind as a bat (mydriasis, cycloplegia)
mad as a hatter (CNS stimulation)
What type of drugs are ganglionic blocking agents and skeletal muscle relaxants?
nicotinic-receptor blocking agents
What do nicotinic-receptor blocking agents do?
they inhibit ach affects at the synapse between preganglionic and postganglionic fibers in the ANS, at the adrenal medulla, and at the skeletal myoneural junction
What are nicotinic-receptor blocking agents used in dentistry for?
therapeutically as skeletal muscle relaxants
What are the 2 types of nicotinic-receptor blocking agents?
competitive nondepolarizing agents
noncompetetive depolarizing agents
this occurs when an antagonist competes with an agonist for the same receptor site; and may be overcome by administration of higher concentrations of ach
nondepolarizing blockade
this occurs when an agonist binds to the receptor site, causes muscle contraction, and then dissociates slowly from the receptor; during the time that the agonist remains bound to the receptor, other agonists are excluded from binding to the same receptor site
depolarizing blockade
atropine, scopolamine, methantheline, propantheline are all what type of drug?
muscarinic cholinergic blocking agents
tubocurarine, metocurine, alcuronium, doxacurium, and pancuronium are all what type of drug?
