Skeletal Muscle Relaxants Flashcards
What is malignant hyperthermia
Hyperthermia that results from massive release of calcium from Sarcoplasmic reticulum. Leads to uncontrolled contraction and stimulation of metabolism in skeletal muscles.
Which enzyme Metabolizes succinylcholine
Cholinesterase in the liver and plasma but it is resistant to acetylcholinesterase
What is the mechanism of action of succinyl choline
Depolarize is the neuromuscular junction. Continuous depolarization results in muscle relaxation and paralysis. In phase two there is repolarization
What are the effects of continuous infusion of succinyl choline
Continuous depolarization changes into gradual repolarization with resistance (sensitization) to depolarization
Why does Cisatracurium replace atracurium?
Because cisatracurium metabolite is less toxic (laudanosine)
Which drugs are metabolized by the liver
- Rocuronium
- Vecuronium
Which drug is used to reverse neuromuscular blockade in rocuronium and vecuronium
Sugammadex
Cholinesterase inhibitors can be used to reverse the effects of the blocker succinylcholine in which phase
Phase 2
What are the toxicities of neuromuscular blockers
- Respiratory paralysis
- Autonomic affects and histamine release
- Special effects of succinylcholine ( Hyperkalemia, peripheral nerve dysfunction, muscle dystrophy)
- Increase intragastric pressure
- Malignant hyperthermia

Patients who are deficient in pseudo esterases have which toxic effect toward succinylcholine
Prolonged apnoea
Which drugs cause histamine release
- Tubocurarine
- Mivacurium
How is malignant hyperthermia caused including succinylcholine
Interaction of succinylcholine with inhaled anaesthetics
Which drugs prolong the relaxant action of neuromuscular blockers
- Aminoglycosides antibiotics
- antiarrhythmic drugs
Which patients are more sensitive to non-depolarizing blockers
Patients with
1. myasthenia gravis
2. severe burns
3. upper motor neuron disease
4. renal failure
Which drugs block cardiac muscarinic receptors
- Pancuronium
- Rocuronium 
Which drug is able to reduce pain caused by severe spasms
Botulinum toxin
Which spasmolytic drugs act in the spinal cord
- Diazepam
- baclofen
- tizanidine
Which drug acts as a GABA(B)  agonist And causes membrane hyper polarization
Baclofen
Which spasmolytic drug is in alpha-2 agonist that acts in the spinal cord
Tizanidine
Which Spasmolytic drug act in the skeletal muscle cell to reduce the release of activator calcium from SR. What receptor Channel does it act on.
Dantrolene On Ryanodine receptor Channel
Which drugs cause malignant hyperthermia
Succinyl choline
tobocurarine
What drug is given to treat malignant hyperthermia and how does it act. 
Dantrolene
blocks calcium release
What are the adverse effects/toxicities of spasmolytic drugs
- Diazepam - sedation
- tolerance
- tizanidine - asthenia, drowsiness, dry mouth, hypotension
- dantrolene - muscle weakness
Which drugs are used for acute muscle spasms
- Cyclobenzaprine
- Maraxalone
- Methocarbamol
- Orphenadrine
Which Spasmolytic drug used for acute muscle spasms may cause confusion and visual hallucinations
Cyclobenzaprine
What are the adverse effects of succinylcholine
- Muscle pain
- hyperkalaemia
- increased intra-gastric and intraocular pressure
Name non-depolarizing skeletal muscle relaxants
- Tubocurarine
- Atracurium
- Cisatracurium
- Mivacurium
- Rocuronium
- Vecuronium
What are the adverse effects of cyclobenzaprine
- M Block
- sedation
- confusion
- ocular effects
What is the second name for Succinyl choline
Suxamethonium
Name two drug that is a depolarizing blocker
Succinyl choline
decamethonium 
Which drug acts directly on the skeletal muscle
Dantrolene
Which drugs act on the CNS
- Diazepam
- methocarbamol
- chlorzoxazone
- tizanidine
- baclofen
- gabapentin
- Thiocochicoside
What happens when non-depolarizing blockers are used with antibiotics
Aminoglycosides inhibit release of acetylcholine
tetracycline and clindamycin also have effects
What is the effect of using loop diuretics or thiazides with non-depolarizing Blockers
Hypo kalaemia caused by loop diuretics/thiazides may potentiate the effect of non-depolarizing blockers
What happens when succinyl choline and Thiopentone Are used together
IV
Precipitation when mixed in the same syringe
Which Group of drugs enhances the effect of non-depolarizing blockers
General anaesthetics and fluorinated anaesthetics
What are the factors affecting the actions of neuromuscular blockers
- pH changes
- hypothermia
- myasthenia gravis
- aminoglycoside antibiotics
- inhalation anaesthetics
Why is a true been administered before neuromuscular blockers
To block the Muscarinic effects of anti-cholinesterase
Which drugs are used to reduce the effect of tubocurarine 
Endorphonium
Neostigmine
Which drug is the most non-depolarizing neuromuscular blocking agent which can be used as an alternative to succinylcholine for tracheal intubation
Rocuronium
