Your SlideShare is downloading. ×
0
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Depolarizing Neuromuscular Blockers
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Depolarizing Neuromuscular Blockers

3,944

Published on

I hope it is useful !

I hope it is useful !

Published in: Education
1 Comment
7 Likes
Statistics
Notes
  • Slide4 (it is not EP. and NE.; it is Ach)....good work
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
No Downloads
Views
Total Views
3,944
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
0
Comments
1
Likes
7
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. DEPOLARIZINGNEUROMUSCULAR BLOCKERS Prepared by: Dr. Sara Khalid Memon 3rd year, MBBS
  • 2. Background :Generally, when an impulse reaches to the muscle, itcauses it to contract when it is excited. This occursin various stages and the main player in this wholesequence is the NEUROTRANSMITTER that isreleased from the nerve ending onto the motor endplate !This neurotransmitter works when binds to thereceptors on the motor end plate. If it binds andcauses intrinsic activity of the receptor then itwould b called as Agonist , and if a substance justbinds to receptors without causing intrinsic activitythen it is said to b Antagonist.
  • 3. 1. Axon2. Motor end plate3. Muscle Fiber4. Myofibril
  • 4. Receptor blockers can be depolarizing or Nondepolarizing depending upon the activity theycause in the motor end plate (muscle).Blockers are said to be non depolarizing when theydo not elicit any action potential or any activity inthe effector and block the action of endogenousligand by just binding to the receptors. On theother hand, Depolarizing blockers are those whichdo elicit the action potentials in the effector butmake effector site desensitized and henceendogenous ligand (epinephrine and norepinephrinehere) is unable to produce response.
  • 5. Depolarizing Neuromuscular Blockersinclude:>> Succinyl-Choline>> DecamethoniumNote: These are not the antagonists in actualsense, infact there action is ofagonist, therefore acetylcholine itselfpharmacologically be used as a depolarizing NMB!
  • 6. Succinylcholine:>Other names: Suxamethonium Chloride(suxamthonium).-Sold under trade names: Anectine, Quelicine, Scoline>Works on the nicotinic receptors (as acetylcholinedoes)> Onset of action is very rapid (within few seconds)and its duration of action doesn’t last for more thenfew minutes.> Degraded by pseudocholine esterase(butyrylcholine esterase in plasma) intosuccinylmonocholine and choline and is excreted inUrine.
  • 7. Mechanism Of Action:Succinylcholine acts on the nicotinic receptors of themuscles, stimulates them and then ultimately causetheir relaxation.> This process occurs in 2 steps;> Phase I: During phase I (depolarizing phase), theycause muscular fasciculations (muscle twitches) whilethey are depolarizing the muscle fibers.> Phase II: After sufficient depolarization hasoccurred, phase II (desensitizing phase) sets in andthe muscle is no longer responsive to acetylcholinereleased by the nerve endings.
  • 8. Explanation:> In normal skeletal muscle, acetylcholine dissociatesfrom the receptor following depolarization and israpidly hydrolyzed by acetylcholinesterase.> Suxamethonium has a longer duration of effect thanacetylcholine, and is not hydrolyzed byacetylcholinesterase. By maintaining the membranepotential above threshold, it does not allow the musclecell to repolarize. When acetylcholine binds to analready depolarized receptor, it cannot cause furtherdepolarization.>This later leads to Paralysis of the affected muscles!!!!
  • 9. Sequence of paralysis:Short muscles are paralysed first then later occursparalysis of other muscles which may lead to death.Finger and orbit muscles Limbs and trunkmuscles Neck muscles Intercostals DIAPHRAGMNOTE:Recovery from paralysis occurs in reverse sequence!
  • 10. Uses of depolarizing neuromuscular blockers(succinylcholine):> For Endotracheal intubation.> during electro convulsive therapy.> For laryngoscopy, bronchoscopy, esophagoscopy> For correction of dislocation and alignment offractures> As a Muscle relaxant !
  • 11. Adverse Effects:> Hyperkalemia> Malignant Hyperthermia> Increased intraocular pressure> Increased cranial pressure> changes in cardiac rhythm, includingbradycardia, cardiac arrest and ventriculardysrhythmias.> For causing death =P
  • 12. The End .. ! THANK YOU !!! =)

×