Autonnomic Drugs I Flashcards
What does the parasympathetic nervous system release on pre/post-ganglionic fibers?
Pre-ganglionic fibers release Ach to excite nicotinic receptors on post PNS fibers
Post-ganglionic PNS fibers release Ach acetylcholine on muscarinic end organ receptors
What are three cholinergic agonists?
Direct stimulation of nicotinic receptors
Direct stimulation of muscarinic receptors
Inhibition of cholinesterase
What is varenicline?
Drug for smoking cessation
How does varenicline work?
Mixed agonist/antagonist of nicotinic receptors mediating dopamine neurons blocking smoking reward
How does arecoline work?
Mixed nicotinic/muscarinic agonist
What is the triphasic response of nicotine?
Initial stimulation of parasympathetic ganglia; stimulation of sympathetic ganglia; prolonged stimulation of adrenal catecholamine release
Which muscarinic receptors are stimulatory?
M1 brain
M3 vasculature
M5 brain vasculature
Which muscarinic receptors are inhibitory?
M2 K channels in heart
M4 CNS neurons
What innervates vascular endothelium?
NO; contain endothelial NO synthase creating NO also PGI2 prostacyclin
Not parasympathetic system
What are the symptoms of organophosphate poisoning?
Salivation Lacrimation Urination Defecation Gastrointestinal Distress Emesis (Pupil constriction)
What drug is to treat organophosphate poisoning?
Pralidoxime (also treat patient with atropine)
What does organophosphate poisoning do?
Inhibition of AChesterase
What is the only ganglionic blocker still used?
Trimethaphan
What are three reversible cholinesterase inhibitors?
Neostigmine
Pyridostigmine
Physostigmine
What are three irreversible inhibitors of cholinesterase?
Demecarium (medical)
Parathion (insecticide)
Saran (humanicide)
(These are organophosphates)
