Blocking Drugs - 1 Flashcards Preview

GK Pharm 2 Exam 2 > Blocking Drugs - 1 > Flashcards

Flashcards in Blocking Drugs - 1 Deck (53)
Loading flashcards...
1

Drugs that affect skeletal muscle function include which two different therapeutic groups? 

neuromuscular blockers

spasmolytics/antispasmodics

 

2

used during surgical procedures and in the intensive care unit (ICU) to produce muscle paralysis

Which drug? 

neuromuscular blockers

3

those used to reduce spasticity in a variety of painful conditions

Which drug? 

antispasmodics/spasmolytics

4

____________________ interfere with transmission at the neuromuscular end plate and lack central nervous system (CNS) activity

neuromuscular blocking drugs

5

How else can neuromuscular blocking drugs be used? 

Adjuncts during general anesthesia to optimize surgical conditions and to facilitate endotracheal intubation in order to ensure adequate ventilation

6

NMB drugs structurally resemble which neurotransmitter? 

acetylcholine

7

__________ is a depolarizing agent. 

Succinylcholine is a depolarizing agent. 

8

What are you the 2 major families of nondepolarizing agents and the drugs beneath them? 

  • Drug class: Isoquinoline
    • tubocuraine
  • Drug class: steroid derivatives
    • pancuronium

9

Which domains on the nicotinic acetylcholine receptror (nAChR) line the channel pore? 

M2

10

Where do the binding pockets for ACh occur? 

α-β and the δ-α subunit interfaces

11

This drug occupies the receptor AND blocks the channel. 

Normal closure of the channel gate is prevented and the blocker may move rapidly in and out of the pore. 

This drug may desensitize the end plate by occupying the receptor and causing persistent depolarization. 

Which drug is this? 

Succinylcholine

12

An additional effect of drugs on the end plate channel may occur through changes in the _____________ surrounding the channel.

General anesthetics and alcohols may impair ________________ by this mechanism

An additional effect of drugs on the end plate channel may occur through changes in the lipid environment surrounding the channel.

General anesthetics and alcohols may impair neuromuscular transmission by this mechanism.

13

What are the names of the idoquinoline derivatives? 

atracurium

cisatracurium

mivacurium

tubocuraine

14

What are the names of the steroid derivatives? 

pancuronium

rocuronium

vecuronium

15

Which isoquinoline derivative has spontaneous elimination? 

atracurium

16

Drugs that are excreted by the _________ typically have longer half-lives, leadring to longer durations of action (>35 minutes). 

Drugs that are excreted by the kidney typically have longer half-lives, leadring to longer durations of action (>35 minutes). 

17

Drugs eliminated by the________tend to have shorter half-lives and durations of action. 

Drugs eliminated by the liver tend to have shorter half-lives and durations of action. 

18

Rapid initial distribution phase followed by a slower elimination phase. 

PK of which drugs? 

NBDs

19

What is succinylcholine mainly used for? 

Used clinically for rapid endotracheal intubation

20

Opens the ion channels causing depolarization and generation of a muscle action potential which results in brief contractions (fasiculations)

Which drug? 

Succinylcholine

21

This drug is not hydrolyzed efficiently by junctional AChE

Persists at the nAChR resulting in sustained local muscle endplate depolarization

Causes the voltage-gated Na channel to remain in the inactive state for a prolonged period

Becomes refractory to further presynaptic release of Ach, and flaccid paralysis results 

Which drug? 

Succinylcholine

22

MOA: Agonist at nicotinic acetylcholine (ACh) receptors, especially at neuromuscular junctions depolarizes

May stimulate ganglionic nicotinic ACh and cardiac muscarinic ACh receptors

Which drug? 

Succinylcholine

23

Initial depolarization causes transient contractions, followed by prolonged flaccid paralysis

Depolarization is then followed by repolarization that is also accompanied by paralysis

Effects of which drug? 

Succinylcholine

24

What are the 2 clinical applications of succinylcholine

1. placement of endotracheal tube at start of anesthetic procedure

2. rarely, control of muscle contractions in status epilepticus 

25

PK of Succinylcholine 

Rapid metabolism by plasma cholinesterase: normal duration ~5 minutes

 

26

What are the 4 toxicities of succinylcholine

arrhythmias

hyperkalemia

transient increased intra-abdominal, intraocular pressure

postoperative muscle pain

27

What are the 2 uses of non-depolarizing neuromuscular blockades Tubocuraine & Pancuronium? 

Facilitate intubation

maintain skeletal muscle relaxation during surgery

28

competitively inhibit normal channel activation preventing muscle cell depolarization, causing flaccid paralysis

Small rapidly moving muscles of the face and eyes are affected first followed by fingers, toes, extremities, trunk, intercostals and lastly the diaphragm

MOA of which drug? 

Non-depolarizing neuromuscular blockade: Tubocuraine and Pancuronium
 

29

How can the action of Tubocuraine and Pancuronium be overcome? 

By increasing the amount of ACh in the synaptic cleft: administer cholinesterase inhibitors like neostigmine or pyridostigmine to shorten the duration of neuromuscular blockade

30

Which class of drugs are usually co-administered with cholinesterase inhibitors? 

What are the names of these drugs? 

What is the benefit of this coadministration? 

Muscarinic receptor antagonists: atropine or glycopyrrolate

Benefit of coadministration: voids the bradydysrhythmias associated with agonism of the cardiac muscarinic receptors