pharmacotherapy & adrenergic drugs Flashcards
(153 cards)
Cholinesterase inhibitors (CI) mechanism of action
- prevent breakdown of ACh by acetylcholinesterase
- increase amt of ACh in the neurologic junction
- more ACh is present to activate receptors,
- INDIRECT CHOLINERGIC AGONISTS
what are the two types of cholinesterase inhibitors
- reversible
- irreversible
what are the reverse cholinesterase inhibitors drug
Neostigmine
Physotigmine
Pyridostigmine
muscular effects of reversible cholinesterase inhibitors
therapeutic dose- increase force of muscle contraction
toxic dose- decrease force muscle contraction
CNS effects of reversible cholinesterase inhibitors
therapeutic doses - mild stimulation
toxic doses- depress CNS function and respiratory drive at toxic doses
(must cross BBB)
indication of Neostigmine
- M. gravy,
- reversal of neuromuscular blockage
- treats MG crisis via IV
counseling points for neostagmine
paradoxical anti-cholinesterase weakness can occur
indication of Physostigmine
reversal of anti-cholinergic toxicity (muscarinic antagonist toxicity)
Physostigmine counseling points
rapid IV administration can cause respiratory depression
- seizures and bradycardia
- give SLOW IV push or infusion
Pyridostigmine indication
MG
Pyridostigmine counseling points
- do not crush ER formulation
- time dose of IR formulation to provide maximal function
- avoid holding or delaying doses
Adverse effects of Reversible Cholinesterase Inhibitors (Neostigmine
Physotigmine
Pyridostigmine)
- Bradycardia
- Hypotension
- increased salivation, lacrimation, sweating
- urinary urgency
- neuromuscular blockade
Echothiophate (irreversible cholinesterase inhibitors) eye drops for glaucoma effect
increase drainage and decrease intraocular pressure
antidote/treatment for irreversible cholinestrerase
pralidoxime
tretaments of irreversible CIs
- Atropine
- Pralidoxime (antidote/treatment for pepticide poisoning)
- Benzodiazepines - seizures
key points about pralidoxime
- forces irreversible CI to dissociate from cholinesterase
- most effective at the neuromuscular junction, cannot cross BBB,
- MUST be given soon after exposure or will not be effective, given IV or IM via SLOW infusion
muscarinic agonists drugs
Bethanechol
Pilocarpine
what does muscarinic agonists bind to
bind to and activate muscarinic receptors
primary neurotransmitter of the parasympathetic NS
acetylcholine
adrenergic receptors of the sympathehtic nervous system
- Dopamine, norepinephrine, epinephrine
- Beta and alpha
cholinergic receptors of the parasympathetic nervous system
Muscarinic and nicotinic
location of nicotinic N receptor
All ganglia of the autonomic nervous system (ANS)
location of nicotinic M receptor
Neuromuscular junctions (NMJ)
effects of nicotinic N receptors activation
Promotes ganglionic transmission