PNS Drugs Flashcards
bethanechol class
Muscarinic Receptor Agonist
bethanechol therapeutic use
Used in tx of urinary retention
-muscarinic activation in bladder results in emptying
bethanechol side effects
-decreased HR
- increased sectretions (sweat, gastric acid and saliva)
-bronchoconstriction
-increased GI motility
-vasodilation -> hypotension
-miosis/ near vision
atropine class
Muscarinic receptor antagonist
bethanechol mechanism
-Reversibly activates mAChRs
atropine mechanism
Reversible inhibits activation of mAChR by ACh
atropine therapeutic use
-used in eye exams/ surgery (causes myadrisis)
-used to increase HR
-used to decrease GI motility (mild dysentery and abdominal cramps)
-antidote to muscarinic agonist poising (ex: mushroom poisoning)
atropine side effects
-tachycardia (increased HR)
-decreased secretions (sweat, saliva, gastric acid)
-blurred vision/ photophobia; increased intraocular pressure
-urinary retention and constipation
-CNS excitation (hallucinations)
Neostigmine class
Cholinesterase inhibitor
Neostigmine therapeutic use
- tx of myasthenia gravis
- reverse effects of pancurium
Neostigmine mechanism
- increase ACh at NMJ by blocking AChE activity -> increase muscle strength
Neostigmine side effects
-excessive mAChR activation
- decreased HR
- increased secretions
- vasodilation (hypotension)
- bronchoconstriction
- increased GI motility
-miosis / near-vision
-excessive ACh in NMJ -> paralysis
Pancurium class
Competitive neuromuscular blocker (Non-depolarizing)
Pancurium therapeutic use
-muscle relaxation
-used in surgery, mechanical ventilation and endotracheal intubation procedures
Pancurium mechanism
-competitively inhibits ACh from binding to nicotinic m receptors -> prevents ACh from stimulating muscle contraction
- molecule -> can’t cross BBB -> no CNS effects
Succinylcholine class
Depolarizing neuromuscular blocker
Pancurium side effects
-respiratory depression/ arrest
- decreased BP (hypotension)
-decreased HR (bradycardia)
Succinylcholine therapeutic use
- muscle relaxation
- used during short procedures
Succinylcholine mechanism
- binds to nicotinic M receptors -> initial activation-> transient muscle contractions -> does not readily release from nAChR -> prevents ACh from binding -> prevents subsequent contractions
Succinylcholine side effects
-malignant hyperthermia
-symptoms: fever, high HR, muscle rigidity, hyperkalemia
Epinephrine class
Adrenergic receptor agonist
Epinephrine mechanism
- activates alpha 1, beta 1 and beta 2 receptors
Epinephrine therapeutic use
- tx for anaphylactic shock
- alpha 1: vasoconstriction (increase BP)
- beta 1: increase HR (restore cardiac function in pts after cardiac arrest)
beta 2: bronchodilaton
Epinephrine side effects
- increased BP (hypertension)
-angina pectoris
-hyperglycemia in diabetic pts (caused by beta 2 activation in the liver increased glycogen breakdown)
