This document discusses neuromuscular blocking drugs, which are used to improve intubation conditions, provide immobility during surgery, and enable better surgical conditions. It describes the structure of the neuromuscular junction and how acetylcholine works at the receptor. Several neuromuscular blocking drugs are mentioned, including atracurium, cisatracurium, mivacurium, pancuronium, rocuronium, and vecuronium. Their dosages, onsets, durations, and side effect profiles are summarized. The document also discusses neostigmine and sugammadex, which are drugs used to reverse the effects of neuromuscular blocking drugs.

1. Neuromuscular blocking
drugs

2. Need for neuromuscular
blocking drugs
 Improve intubating conditions
 Providing immobility
 Better surgical conditions

3. Structure of neuromuscular
junction
 Motor neuron
 Axon
 Nerve terminals
 Synaptic cleft
 Post synaptic membrane

4. Action potential
 Electrical potential inside the cell is
negative
 Depolarization
 Sodium and calcium channels
 All or none response

5. acetylcholine
 Acetylcholine synthesis
 Receptors
 Vesicles
 Anticholinesterases
 Synaptic cleft
 Calcium and magnesium

6. Post synaptic events
 Ach receptor
 Ligand gated ion channel
 Structure of the receptor
 Adult ,fetal ,extrajunctional
 acetylcholinesterase

7. Presynaptic events
 Presynaptic receptor
 Preventing mobilisation of acetylcholine
vesicles

8. Pharmacologic characteristics
 Potency
 Onset
 duration

9. atracurium
 Hoffman reaction
 Nonspecific ester hydrolysis
 Dose 0.5 mg/kg
 Onset 3 -5 min
 Duration 30 – 45 min

10. Specific points
 Histamine release
 Intubating dose
 Maintenance of anaesthesia
 Can be used in patients with hepatic or
renal failure

11. cisatracurium
 Dose 0.1 mg/kg
 Duration 30 -45 min
 Devoid of histamine releasing properties

12. mivacurium
 Short acting
 Degraded by plasma esterases
 0.3. mg/kg
 Ambulatory and laprascopic surgery

13. pancuronium
 Increase heart rate,blood pressure and
cardiac output
 Sympathomimetic effect
 Duration of action 1 hr
 Higher incidence of muscular weakness
after cardiac surgery than rocuronium

14. rocuronium
 0.6 mg/kg intubating dose
 Duration 30 -40 min
 No hemodynamic effects
 Rapid sequence induction
 sugammadex

15. vecuronium
 Intubating dose 0.1 mg/kg
 No cardiovascular effects
 Excreted by the kidney
 Intermediate duration of action
 Precipitates with thiopentone

16. neostigmine
 Reversible anticholinesterase inhibitor
 50 -70 mcg/kg
 Increased acetylcholine in the receptor
 Profound vagal stimulation
 Administered with glycopyrrolate or
atropine

17. sugammadex
 Gamma cyclodextrin
 Steroid nucleus –rocuronium and
vecuronium
 No cardiovascular adverse effects
 16 mg/kg dose required

18. Special considerations
 Myasthenia gravis
 Myotonia
 Burns
 Muscular dystrophy
 UMN lesions