Cholinergic Receptor-Inhibiting Drugs Flashcards Preview

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Flashcards in Cholinergic Receptor-Inhibiting Drugs Deck (13):
1

Succinylcholine

 
  • depolarizing NMJ blocker
  • produces fasciculations then flaccid paralysis w/i 1 min
  • used for tracheal intubation bc effects last only 5-10 mins (via rapid hydrolysis by plasma AChE)

**think: S for Succinylcholine and faSciculations (depolarizing NMJ blocker)

2

atropine

  • anti-muscarinic (from belladona plant)
  • produces mydriasis (pupil dilation) and cycloplegia (loss of accomodation)

** atropine fever/hyperthermia = blockage of sympa (cholinergic) sweat gland can be lethal in children!

3

antimuscarinic drugs and their toxicity

  • benzotropine, scopolamine, atropine, tropicamide, ibatropium, tiotropium, dicyclomine, tolterodine
  • Dry as a bone (reduced sweating, lacrimation and salivation); blind as a bat (excessive pupillary dilation); red as a beet (dilation of cutaneous vessels); mad as a hatter (inhibition of muscarinic receptors in CNS)

** non-selective bc they don't discriminate between M1-M5

Note: at low doses you get slight cardiac slowing due to blockage of inhibitory autoreceptors (M2)

3

Ibatropium and Tiotropium

  • anti-muscarinic
  • treat asthma/COPD (bronchodilation)

** think: "trop"--> choke --> asthma/COPD

4

Botulinim Toxin A

  • degrades SNAP25 and inhibits synaptic vesicle fusion --> no ACh release --> no contraction
  • cosmetic purposes
  • treats achalasia (abnormal esophageal contractions), strabismus, oromandibular dystonia (spasms of face, jaw)

5

dicyclomine

  • anti-muscarinic
  • to reduce transient hypermotility of GI tract

*** think: I would die if I couldn't reduce GI tract hypermotility

6

Tolterodine

  • anti-muscarinic
  • treat transient cystitis, post-op bladder spasms or incontinence

**think: TTTolterodine = CysTTiTTis and inconTTinence

8

scopolamine

  • anti-muscarinic
  • treat motion-sickness

* think S (scopolamine= sickness)

9

NMJ blockers

  • inhibit Nm receptors
  • used as muscle relaxants
  • Non-depolarizing blockers act as antagonists that competitively inhibit ACh binding (Tubocurarine)
  • depolarizing blockers act as super-agonists that overstimulate the receptor and prevent repolarization (you will see initial transient contraction then relaxation due to desensitization)   --- Succinylcholine

10

Hexamethonium

  • ganglionic blocker (acts on Nn receptor)
  • use for Hypertensive crisis (think "H"), bloodless-field surgery
  • non-selective bc they inhibit Nn receptors at both sympa and PS ganglia --> broad-range of undesirable effects

11

benzotropine

  • anti-muscarinic
  • treat Parkinson's

12

tropicamide

  • anti-muscarinic
  • produces mydriasis and cycloplegia
  • used by eye doctors think: tropicEYEmide
  • **very rapidly hydrolyzed

13

Tubocurarine

  • blocks Nicotinic (Nm) receptor
  • non-depolarizing NMJ blocker
  • produces flaccid paralysis (lasts 30-60 mins)
  • used for muscle relaxation during surgery w/o deep anesthesia
  • AChE inhibitors can reverse the effect (produces more ACh to compete with drug)