Chapter 17: Muscarinic Antagonists Flashcards
Muscarinic antagonists are also known as
- parasympatholytic drugs
- antimuscarinic drugs
- muscarinic blockers
- anticholineric drugs
muscarinic antagonists oppose
BLUCHPADS BBC
- muscarinic agonists
treat overdose of muscarinic antagonists with
physostigmine
Atropine mechanism of action
competitive blockage of the actions of Ach at muscarinic receptors
at high doeses atropine will block ____ recpetors too
nicotinic
atropine effect on the heart
increases heart rate
atropine effect on exocrine glands
decreases secretions
atropine effects on smooth muscles
relaxes bronchi, decreases tone of urinary bladder detrusor, and decreased tone and mitility of GI tract
atropine effect on eyes
mydriasis and cycoplegia
atropine effect on the CNS
mild excitation of hallucinations and delirium
atropine therapeutic uses
- preanaesthetic medication
- diorders of the eye
- bradycardia
- intestinal hypertonicity and hypermobility
- muscarinic agonist poisoning
- peptic ulcer disease, astma (rare)
- biliary colic
what is the half life of atropine
3 hours
atropine adverse effects
- xerostomia (dry mouth)
- blurred visions and photophobia
- elevation of intraocular presssure
- urinary retention
- constipation
anhidrosis - tachycardia
- asthma (thicken bronchial secretions)
where to avoid atropine
- older adults, cation in pregnancy and breast feeding
what is the specific anticholinergic drug for overactive bladder
Oxybutynin [Ditropan]
Oxybutynin [Ditropan] mechanism of action
anticholinergic agent that acts primarily at M3 muscarinic receptors ( (salivary glands, bladder, Gi, Eyes)
Oxybutynin should be used with caution in
the elderly
oxybutynin side effects
common
oxybutynin
- very soluable
- T1/2: 2-3 hours
what are symptoms of the toxicolody of muscarinic antagonists
- dry mouth
- blurred vision
- photophobia
- hyperthermia
- CNS effects
- hot, dry, flushed skin
what is the treatment for the toxicology of muscarinic antagonists
- prysostigmine
- can also use activated charcoal
