ANS Pharm: Cholinergics & Muscarinics Flashcards
nicotine
(ACh agonist/cholinomimetic)
atropine, scopolamine, glyco are ACh antags/antimuscarinics
cholinergic agonists mimic ACh but differ in (2)
their nicotinic & muscarinic activities
&
doA
T/F:
Muscarinic antagonist toxicity will cause SNS stimulation.
True
Where does nicotine act?
activates both SNS & PNS post-ganglionic neurons (Nn subtype)
(as ACh would)
Systemic effects of nicotine
- equally activates SNS & PNS ganglia
- cancel each other out @ many end organs
- CV: lacks PNS BP regulation = unopposed SNS constriction
- heart rate: conflicting signals affect rhythm
The cholinergic agonists
- nicotine
- methacholine
- bethanachol
- carbamylcholine
- pilocarpin
methacholine
cholinergic agonist (M3) that provokes airway reactivity for subclinical asthma
-bronchoconstriction
-airway secretions
-impairs peak flow
bethanachol
relatively M3 selective for GI, urinary
for nonobstructive urinary retention
carbamylcholine & pilocarpin
miosis
treats glaucoma
Alzhemiers
belladonna alkaloids
atropine & scopolamine
(tertiary amines)
Why do we prefer glyco for secretions?
no CNS effects
&
less effect on HR
Atropine in low doses (__ mg) may cause or worsen bradycardia by….
<0.1 mg
blocks presynaptic M1 receptors on preganglionic PNS fibers
physostigmine
what does it treat and whats the dose?
central antigcholinergic syndrome
1-2 mg IV
(redose if needed as its doA may be shorter than the anticholinergic)
Physostigmine is (non/competitive)
competitive
Which anticholinergic will not prevent motion sickness?
glyco
atropine & scopolamine can
Which anticholinergic causes the least effect on HR?
scopolamine
at the sympathetic ganglia
