Pharm Skeletal Muscle Relaxants

Front 1

Question: Characteristics of phase I depolarizing neuromuscular blockade due to succinylcholine include?

Back 1

Well-sustained tension during a period of tetanic stimulation.

Front 2

Question: PT underwent a surgical procedure of 2 h. Anesthesia provided was isoflurane with IV midazolam and a nondepolarizing muscle relaxant. At the end of the procedure, low dose atropine was administered followed by pyridostigmine.

Atropine was given to?

Atropine would probably not be needed during reversal of a nondepolarizing relaxant actions if the agent used was?

Back 2

Prevent activation of cardiac muscarinic receptors. Acetylcholinesterase inhibitors increases ACh at all sites. To offset bradycardia, a muscarinic blocker is used. Glycopyrollate is preferred since it lacks CNS effects, but atropine is effective.

Pancuronium, which can block muscarinic receptors, especially in the heart. Sometimes can cause tachycardia and hypertension.

Front 3

Question: Characteristics of nondepolarizing neuromuscular blockade includes?

Back 3

Poorly sustained tetanic tension.

Front 4

Question: Which of the following drugs is the most effective in the emergency management of malignant hyperthermia?

Back 4

Dantrolene, which blocks Ca release from sarcoplasmic reticulum.

Front 5

Question: The clinical use of succinylcholine, especially in PTs with diabetes is associated with?

Back 5

Elevated intragastric pressure, which can cause regurgitation and aspiration of gastric contents.

The complication is increased with PTs who have delayed gastric emptying, such as diabetic PTs.

Front 6

Question: A 22 yr old anesthesia PT with normal hepatic and renal function was given a bolus IV dose of neuromuscular blocker that should have lasted only 5 - 10 min. Instead, the PT required mechanical ventilation for over 8 h. What is accurate?

Back 6

This is a good example of genetic variation in drug metabolism.

Front 7

Question: What drug is most often associated with hypotension caused by histamine release?

Back 7

Tubocurarine: releases histamine and ganglionic blockade.

Note: Tizanidine: hypotension via alpha2 activation like clonidine.

Front 8

Question:

Cyclobenzaprine is likely to?

Dantrolene has minimal effect on?

Diazepam causes sedation at?

Intrathecal use of baclofen is effective in?

Back 8

Dry oropharyngeal secretions and decrease gut motility.

Ca release from cardiac muscle.

The usual dose required to reduce muscle spasms.

Some refractory cases of muscle spasticity.

Front 9

Question: What drug is most likely to cause hyperkalemia leading to cardiac arrest in PTs with spinal cord injury or muscular dystrophy?

Back 9

Succinylcholine, which releases K from the cells, ensuring hyperkalemia.

Note: PTs mostly at risk: extensive burns, spinal cord injuries, neurologic dysfunction, intra-abdominal infection.

Front 10

Question: Atracuricum is?

Back 10

Inactivated partly by spontaneous breakdown to form laudanosine, which has a long half-life.

Note: laudanosine enters the CNS and can cause seizures. Prolonged administration is to be avoided.

Front 11

Question: Which drug has spasmolytic activity and could also be used in the management of seizures caused by overdose of a local anesthetic?

Back 11

Diazepam

Front 12

Question: Myalgias are a common postoperative complaint of PTs wwho receive large doses of succinylcholine, possibly the result of muscle fasciculations caused by depolarization. Which drug administered in the operating room is used to prevent postoperative pain caused by succinylcholine?

Back 12

Depolarizing blockers: cisatracurium, pancuronium, tubocurarine, atracurium, mivacurium, vecuronium, rocuronium

Front 13

Question: In anesthesia protocols that include succinylcholine, what is a premonitory sign of malignant hyperthermia?

Back 13

Trismus: contraction of jaw muscles.

Front 14

Skeletal muscle contraction is evoked by?

Clinically, why is provoking skeletal muscle relaxation useful?

Back 14

Nicotinic cholinergic transmission.

Surgical relaxation, tracheal intubation, and control of ventilation.

Front 15

What is the MOA of nondepolarizing drugs?

Back 15

Compete with ACh at the receptor, and their effect is reverse by cholinesterase inhibitors.

Post-tetanic potentiation is preserved, but tension during the tetanus fades rapidly.

Larger muscles (e.g., abdominal, diaphragm) are more resistant to neuromuscular blockade, but they recover more rapidly to smaller muscles (eg., hand, facial).

Front 16

Succinylcholine MOA?

Back 16

Acts like a nicotinic agonist and depolarizes the neuromuscular end plate.

Front 17

What is Phase I and II of succinylcholine?

Back 17

I: continuous depolarization. Initially, there may be twitching and fasciculations (prevented by pretreatment with non-depolarizing blocker).

II: Without periodic repolarization, continuous depolarization results in muscle relaxation and paralysis.

Front 18

What are two cholinesterase inhibitors?

Their effects on non-depolarizing blockers? With what phase?

Back 18

Neostigmine or pyridostigmine.

They can reverse the actions of non-depolarizing drugs.

Paralysis produced by depolarizing blocker, succinylcholine, is increased by cholinesterase inhibitors in phase I.

During phase II, the block produced by succinylcholine is usually reversible by cholinesterase inhibitors.

Front 19

What is succinylcholine SE?

Its purpose?

Back 19

Muscle pain, hyperkalemia, increase in intragastric pressure caused by fasciculations may result in regurgitation of gastric contents

Muscle paralysis for endotracheal intubation.

Front 20

SE of succinylcholine with inhaled anesthetics?

What is the early sign of this condition?

Back 20

Malignant hyperthermia.

Trismus: contraction of the jaw muscle.

Front 21

Who is more sensitive to nondepolarizing blockers?

Less sensitive?

Back 21

Myasthenia gravis PTs

Burn PTs or those with UMN disease due to proliferation of extrajunctional nicotinic receptors.

Front 22

What are some neuromusuclar blocking, nondepolarizing drugs?

Back 22

Tubocurarine, atracurium, mivacurium, pancuronium, vecuronium, rocuronium

Front 23

What drugs can be used for chronic spasm?

A BZ

GABA agonist

Congener of clonidine

Agent that acts on sarcoplasmic reticulum of skeletal muscle.

Back 23

Diazepam

Baclofen

Tizanidine

Dantrolene

Front 24

Botulinum toxin can be used for?

Back 24

To reduce pain caused by severe spasm. Also for ophthalmic purposes and cerebral palsy.

Front 25

What two seizure drugs can be used as a spasmolytic in PTs with MS?

Back 25

Gabapentin and pregabalin.

Front 26

What are the three spasmolytic drugs that act on the spinal cord, MOA?

Back 26

Baclofen: GABAb agonist on presynaptic and postsynpatic receptor

Diazepam: GABAa receptor

Tizanidine: related to clonidine, has alpha2 agonist activity, reinforces presynaptic inhibition in the spinal cord.

Front 27

What is the spasmolytic drug that acts on the muscle? MOA, and used to alleviate malignant hyperthermia induced by succinylcholine or tubocurarine with general anesthesia?

Its SE

Back 27

Dantrolene reduces Ca from sarcoplasmic reticulum via interaction with the ryanodine receptor

Muscle weakness

Front 28

What provokes histamine release?

Laudanosine formation?

Muscle relaxation is potentiated by?

Back 28

Mivacurium and tubocurarine

Atracurium

Inhaled anesthetics, aminoglycosides, possibly quinidine.

Front 29

SE of:

Baclofen

Diazepam

Tizanidine

Back 29

Sedation, muscle weakness

Sedation, additive with other CNS depressants; abuse potential.

Muscle weakness, sedation, hypotension.

Front 30

What is cyclobenzaprine used for? MOA, and SE?

Back 30

Treatment of acute spasm from muscle injury.

Interferes with polysynpatic reflexes that maintains muscle tone.

Confusion and visual hallucination