Cholinergic pharm-Pechnick Flashcards
What is the rate limiting step in the life cycle of acetylcholine?
The uptake of choline
What are the two types of ACh receptors?
- Muscarinic - slow
2. Nicotinic - fast
What type of receptors are muscarinic?
G protein
What types of receptors are nicotinic?
Ligand gated
Where are nicotinic receptors?
- Parasympathetic ganglia
- Sympathetic ganglia
- Adrenal medulla
- Neuro-muscular junction
Where are muscarinic receptors?
- Parasympathetic end organ terminals
2. Sweat glands (Sympathetic cholinergic)
What gets rid of ACh?
Cholinesterases
What are the SE of muscarinic agents?
Defecation Urination Miosis Bradycardia Bronchospasm Emesis Lacrimation Lethargy Salivation
Acetylcholine, Methacholine, Bethanchol, Carbachol, Pilocarpine, Cevimeline
- Direct Cholinergic Agonists
- Acetylcholine & Carbachol: both nicotinic & muscarinic effects
- All others are primarily muscarinic
Nicotine
- Interacts with nicotine receptors all over body
- Low doses stimulate, high doses inhibit
- Extremely toxic (esp. children)
What are the classes of Acetylcholinesterase inhibitors?
- Alcohols - short acting
- Carbamates - intermediate acting
- Organophosphates - irreversible
What do Acetylcholinesterase (AChE) inhibitors do?
- Increase levels of ACh at all cholinergic synapses
- Parasympathetic effects!
What does AChE inhibitor toxicity result in?
DUMBELLS + ganglionic effects + neuromuscular blockade
Edrophonium
- Short acting AChE inhibitor
- Does not cross BBB
- Used to diagnose MG
Donepezil, Rivastigmine, Galantamine, Neostigmine, Pyridostigmine, Ambenoium, Guanidine
- Intermediate acting AChE inhibitors
- Effects are slowly reversible
