Discovering Drugs Flashcards
What agents act on NM junction level?
Anticholinergic
Anticholinesterase
Neuromuscular blockers
What is the function of an anticholinergic drug?
Substance that block ACh in central and peripheral NS
named by the receptors affected:
Antimuscarinic, blocks the muscarinic receptors preventing ACh from binding
Antinicotonic, blocks the nicotinic receptors preventing ACh from binding
What is the function and effect of atropine and scopolamine?
They are anticholinergic, antimuscarinic
Parasympatholytic effect
What is the meaning of parasympatholytic?
The inhibition of ACh mediated stimulation by competitive occupancy (antagonist) of muscarinic receptors. Prevents ACh to bind
What is the parasympatholytic effects?
Produce Tachycardia (the inhibitatory effect of heart rhytm ceases)
Bronchodialation
Limit respiratory and GI tract gland secretion
Reduce GI tract motility
Produce dilation of pupils (mydriasis)
What is the function of a anticholinesterase agent?
Acetylcholinesterase inhibitor
Inhibits the acetylcholinesterase= no hydrolysis of ACh= increases level and duration of the action of ACh= muscular spasm
Gives spastic paralysis
What is the function and effect of the drugs purostigmine and neostigminne?
Affecting both the effect at neuronal endplate, the acetylcholinesterases acts on nicotinic receptors and muscarinic receptors in heart, exocrine glands and smooth muscle cells
Gives parasympathomimetic effects
What is the meaning of parasympatomimetic?
Bracicardia (slow heart rate)
High salivation
Increase intestinal motility, vomiting, diarrhea
Bronchospasm and bronchorrhea (increased bronchial secretion)
Contraction of pupils (miosis)
What can be used to reduce the effects of parasympathomimetic agents?
ATROPINE!!!
What is the different kinds of neuromuscular blockers?
Depolarizing neuromuscular blocking agents (DNMB) such as SUCCINYLCHOLINE
Non-depolarizing neuromuscular blocking agents (NDNMB) such as ATRACURIUM
What is the function and effects of DNMB such as succinylcholine?
Depolarizes muscle membrane like ACh
Resistance to AChesterases for longer periods
Causes twitching of the muscles (fasciculation)
Prolonged depolarization of the end-plate region
Leads to failure of AP generation
NO reversal agents
What is the function and effects of NDNMB such as atracurium?
Competitive inhibition, blocks AChreceptors without activating them
Caused loss in ability to contract skeletal muscles
Acts on both nicotinic and muscarinic receptors
Reversal agent=anticholinesterase
