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28 Cards in this Set
- Front
- Back
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depolarization of muscle fibers occurs when... |
ACH combines w/Nm receptors |
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Muscle relaxation occurs when... |
ACH hydrolyzed by acetylcholinesterase. This terminates ACH action. |
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centrally acting skeletal muscle relaxant |
inhibits skeletal muscle contraction by blocking conduction within spinal cord |
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Peripheral skeletal muscle relaxant |
inhibit at NMJ or within contractile process |
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when skeletal muscle relaxation desired |
spastic diseases (MS, CP) spinal cord damage (trauma, paraplegia) injuries when pain accompanies muscle overexertion surgical, orthopedic procedures, intubation (bronchoscopy)
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2 types neuromuscular blockers |
nondepolarizing (curare, pancuronium) depolarizing (succinylcholine) |
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Non depolarizing blockers mechanism of action |
occupy Nm sites, ACH cant combine w/receptors, depolarization cant occur |
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prototype non-depolarizing drug |
Curare |
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Modern non-depolarizing drugs end in |
-curium -curomium |
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non depolarizing drug examples |
Mivacurium (duration 10-20 mins) Pancuronium bromide (duration 30+ mins) Rocuronium bromide (Zemuron) (up to 30 mins) Atracurium besylate (30 mins) Cisatracurium besylate (NImbex) (30 mins) Curare (duration up to 60 mins) |
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Depolarizing blockers |
produces paralysis by 1st causing nerve transmission (observed as fasciculations), then inhibiting it (no response to ACH) |
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Succinylcholine |
only available depolarizing neuromuscular blocking drug |
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ACH |
neurotransmitter in NMJ |
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nondepolarizing blockers administration |
IV |
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Recovery of muscle function from nondepolarizing blocker |
as drug is metabolized, excreted |
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Vagolytic action |
inhibition of Vagus nerve to heart, causing tachycardia (counteraction to vagal tone that causes bradycardia) |
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Succinylcholine |
can produce ventricular arrhythmias, changes in BP Can cause muscle breakdown and life threatening arrhythmias and cardiac arrest in children potentiated by digitalis, diuretics |
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atracurium mivacurium succinylcholine |
cause release of histamine from mast cells, can lead to bronchospasms, increased secretions in sensitive patients (asthma) |
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Major toxicity associated with neuromuscular blockers |
paralysis of respiratory muscles, life threatening |
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skeletal muscle paralysis caused by non depolarizing blockers reversed with? |
neostigmine edrophonium
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Sugammadex |
1st in new class selective relaxant binding agent (SRBA) reverses neuromuscular blockade of nondepolarizing blockers by encapsulating, chelating the blocker. special affinity for rocuronium |
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Succinylcholine OD |
No Known antidote drug must be metabolized |
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Malignant hyperthermia |
drastic increase in body temp can be caused by normal dose succinylcholine in combination w/inhalation anesthetic |
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Dantrolene |
direct acting peripheral skeletal muscle relaxant perevents actin, myosin from interacting, preventing muscle contraction. Blocks release of calcium ions Acts within muscle cell at calcium storage centers |
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Sarcoplasmic reticulum |
organelle in muscle cell releases calcium ions during contraction, absorbs calcium ions during relaxation |
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Dantrolene clinical indications |
malignant hyperthermia, spastic conditions (MS, CP, spinal cord injuries) relaxes spastic skeletal muscle interferes w/calcium release |
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Dantrolene adverse effects |
dizziness, vomiting, fatigue, weakness potential for hepatoxicity Contraindications- hepatitis, cirrhosis, other hepatic diseases Can be potentiated by alcohol, antiarrhythmics (lidocaine, procainamide, quinidine) antibiotics, general anesthetics, narcotic analgesics, tranquilizers, sedatives |
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Spasmolytics |
jjj |
