Cholinergic Drugs

Receptor: Muscarininc
1. Heart, smooth muscles, brain, exocrine glands
Receptor: Nicotinic
1. CNS, adrenal medulla, autonomic ganglia, NMJ
CH Agonist
1. Direct acting
  1. Parasympathomimetics. Mimics Ach by binding directly to Ch receptors. Longer duration.
  2. Bethanecol
    1. Muscarinic action, bradycardia, increased excretion, bronchoconstriction, inc in GIT, dilate BV
      1. Urinary retention, esp postpartum/postopertive
        Hypotension, bronchoconstriction, excessive excretion, dysrhythmia in hyperthyroid pt
        Urinary obstruction, hyperthyroid pt
      2. Oral, 1 hr
  3. Pilocarpine
    1. Topical appl to produce rapid meiosis, cilliary contraction
      1. Glaucoma by lowering of intra-ocular pressure
        Blurred vision, nightblind, brow ache
      2. Topical, 4-8 hrs
2. Indirect acting
  1. Anti-cholinesterases, leading to accumilation of ACh, broad spectrum
  2. Neostigmine
    1. ChE splits N slower than ACh, bradychardia, bronchoconstriction, incr excretion, urination, GI motility
      1. Myasthenia Gravis
        Excessive muscarinic stim: salivation, inc GI, urinary urgency, bradychardia, sweating, miosis
        GI/Urinary obstruction, peptic ulcer, asthma, hyperthyroidism
      2. Orally
CH Antagonist
1. Agents that bind to Ch receptors to prevent action
2. Anti-muscarinic
  1. Parasympatholitic. Block muscarinic receptors. Little effect on skeletal NMJ or autonomic ganglia
  2. Atropine
    1. Muscarinic block, incr HR, decrease secretions, bronchorelaxarion, decrease GI/Urinary, mydriasis, mild CNSstimulation
      1. Pre-anaesthetic to prevent brachycardia
        Xerostomia, inc intra-ocular P, urinary retention, constipation, anhydrosis
        Antihistamine
        Hallucinations, children are sensitive
      2. Orally, topically, IV, IM, suncutaneous
    3. Reverse effect
  3. Scopolamine
    1. Anti-motion sickness, block short-term memory, sedation
      1. Topical patch
      2. Anti motion sickness and post operative nausea and vomiting
        Dry mouth, blurred vision, tachycardia, urinary retention. CNS – restless, confusion, hallucinations
3. NM-Blockers
  1. De-polarising
    1. Binds to Ach receptor, but then remains in state of depolarisation
    2. Succinylcholine
      1. See above. Constant depolarization causes muscle paralysis, pesists until drug levels decline and dissociate from receptors
        IV, 1-10 min
        Muscle relaxation (endotracheal intubation, endoscopy)
        Hyperkalemia, postop muscle pain, malignant hyperthermia, apnea
      2. Don't mix
  2. Non-depolarising
    1. Compete with Ach, do not depolarise motor end-plate
    2. Cisantracurium
      1. Block activation of Ach, muscle relaxes
        IV, 1 min - 1hr
        Skeletal muscle relaxation (surgery, mech ventilation, endotracheal intubation, hypotension d/t release of histamine/block nicotinic receptors, no effect on CNS
        Respiratory arrest, hypotension
  3. Blocks nicotinic receptors @ NMJ, causing skeletal muscle relaxation
Parasympathetic
1. Slows HR
  1. Increase gastric secretion
    1. Constrict pupil
      1. Empty bladder/bowel

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Cholinergic Drugs

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	Erstellt von Lindie Metz vor mehr als 8 Jahre