USMLE step 1 Pharmacology -
Autonomic Nervous System
Exam 2023-2024
α1, α2, β1, β2 - ANS-Epinephrine
α1, α2, β1 (no β2 activity) - ANS-Norepinephrine
Causes an inhibitory cell hyperpolarization - ANS-GABA
Uses DAG & IP3 as 2nd messengers, Parasympathetic control - ANS-Muscarinic-r
Cholinergic. ↑ GI & Bladder motility. Txt atonic bladder post-op - ANS-Bethanechol
Cholinergic. Pupillary constriciton= miosis. Ciliary constriction= accomodation. Txt acute
glaucoma - ANS-Pilocarpine
Organophosphate. Irreversible acetylcholinesterase (-)r - ANS-Isoflurophate
2PAM. Reverses organophosphate binding to acetylcholinesterase, - ANS-Pralidoxime
Reversible acetylcholinesterase (-)r, Txt Myasthenia Gravis - ANS-Neostigmine
Anitbodies to Ach-r. ↑g muscular weakness due to Achs weak postsynaptic effect @
NMJ. Inactivates-r - ANS-Myasthenia Gravis
Nondepol. Competitive cholinergic N-r (-)r., Prevents Ach binding but does not activate
NMJ, ↑ Histamine release= ↓ BP & ↑ bronchospasm - ANS-Tubocurium
Nonselectively binds N-r of the PS- and SNS - ANS-Trimethaphan
More potent than tubocurium w/o histamine release - ANS-Pancurium
Depol. Non competitive (-)r of muscle aciton, Opens Na Ch.= fasciculations. Closes Na
Ch.= paralysis. Continuous infusion. - ANS-Succinylcholine
receptor? Mydriasis due to norepinephrine. Prazosin (-). - ANS-α1 & Eye
receptor? Miosis due to Ach. Atropine (-). - ANS-M-r & Eye
Post ganglionic symapthetic fibers releases norepinephrine - ANS-Sympathetic
