Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > Anxiolytics and Hypnotics > Flashcards

Anxiolytics and Hypnotics Flashcards

1
Q

What are the four main proteins that make up the GABA-A receptor?

A

GABA receptor protein
Benzodiazepine receptor protein
Barbiturate receptor protein
Chloride channel protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What protein links the GABA receptor proteins and the benzodiazepine receptor protein?

A

GABA modulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the normal physiological action of GABA.

A

GABA binds to the GABA receptor protein
GABA modulin links the GABA receptor protein and the benzodiazepine receptor protein
This results in opening of the chloride ion channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name a competitive antagonist of the GABA receptor protein.

A

Biciculline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name a competitive antagonist of the benzodiazepine receptor protein.

A

Flumazenil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the two main effects of benzodiazepines that facilitate GABA neurotransmission?

A

They facilitate the GABA-mediated opening of the chloride channel
They facilitate the binding of GABA to its receptor protein (increase theaffinity of GABA to the GABA binding site) – this is reciprocated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the three main effects of barbiturates that facilitate GABA neurotransmission?

A

They enhance the normal physiological action of GABA
They enhance GABA binding to the GABA receptor protein (NOT reciprocated)
At higher concentrations, barbiturates can have a direct action on the chloride channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the key difference in the mechanism of action of barbiturates and benzodiazepines?

A

Benzodiazepines – increase the frequency of chloride channel opening
Barbiturates – increase the duration of chloride channel opening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the relative difference in selectivity between barbiturates and benzodiazepines?

A

Barbiturates are LESS selective
This may explain why barbiturates induce surgical anaesthesia and why barbiturates are less safe than benzodiazepines
NOTE: barbiturates also reduce excitatory transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name a barbiturate that is used as an anaesthetic.

A

Thiopentone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name three barbiturates and benzodiazepines that are used as anti-convulsants.

A

Diazepam
Clonazepam
Phenobarbital

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name a benzodiazepine that is used as an anti-spastic.

A

Diazepam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are two other clinical uses of benzodiazepines and barbiturates?

A

Anxiolytics

Hypnotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define anxiolytic.

A

Remove anxiety without impairing mental or physical activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define sedative.

A

Reduce mental and physical activity without producing loss of consciousness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define hypnotic.

A

Induces sleep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What structure is common to all barbiturates?

A

Six-membered ring (4 carbons and 2 nitrogens)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Barbiturates have been largely superseded by benzodiazepines. Which barbiturate is still used relatively commonly?

A

Amobarbital

19
Q

What is the half-life of this drug?

A

20-25 hours

20
Q

What are the unwanted effects of barbiturates?

A

Low safety margin (overdose can be lethal)
Alters natural sleep (reduced REM)
Enzyme inducers
Potentiate the action of other CNS depressants (e.g. alcohol)
Tolerance
Dependence

21
Q

What structure is common to all benzodiazepines?

A

They are tricyclic

22
Q

What are the three key benzodiazepines?

A

Diazepam
Oxazepam
Temazepam

23
Q

What is the difference between all the benzodiazepines that are in clinical use?

A

Their pharmacokinetics

24
Q

Describe the administration of benzodiazepines.

A

Well absorbed per orally

Peak plasma concentration after about 1 hour

25
Q

When would you give IV benzodiazepines?

A

Treatment of status epilepticus

26
Q

Describe the distribution of benzodiazepines.

A

Bind strongly to plasma proteins

Highly lipid soluble

27
Q

Describe the metabolism of benzodiazepines.

A

Extensively metabolised in the liver

28
Q

Describe the excretion of benzodiazepines.

A

Excreted in the urine as glucuronide conjugates

29
Q

Describe the duration of action of benzodiazepines.

A

Varies a lot

This allows classification as short-acting and long-acting benzodiazepines

30
Q

What makes long-acting benzodiazepines have a long duration of action?

A

They have slower metabolism

They generate active metabolites

31
Q

Name two short-acting benzodiazepines.

A

Oxazepam

Temazepam

32
Q

Name a long-acting benzodiazepine.

A

Diazepam

33
Q

Describe the metabolism of oxazepam.

A

It is metabolised straight to its glucuronide conjugate (t1/2 = 8 hours)

34
Q

Describe the metabolism of temazepam.

A

Metabolised to oxazepam and then to the glucuronide conjugate

35
Q

Describe the metabolism of diazepam.

A

Metabolised via temazepam and oxazepam to the glucuronide conjugate
Some diazepam is metabolised to nordiazepam and then oxazepam

36
Q

Name three drugs that are used as anxiolytics.

A

General rule – long-acting benzodiazepines
Diazepam
Chlordiazepoxide
Nitrazepam

37
Q

Under what condition would you use a short-acting benzodiazepine as an anxiolytic?

A

Hepatic impairment – this means that the benzodiazepines and metabolised more slowly – drug of choice = oxazepam

38
Q

Name two drugs that are used as sedatives/hypnotics.

A

General rule – short-acting benzodiazepines
Oxazepam
Temazepam

39
Q

Name a long acting drug that might be used as a sedative/hypnotic.

A

Nitrazepam (t1/2 = 28 hours)

40
Q

What are the advantages of benzodiazepines over barbiturates?

A

Wide margin of safety
 Overdose causes prolonged sleep (but this is rousable)
 Flumezanil can be given IV if a patient has overdosed
Mild effect on REM sleep
Do NOT enhance liver enzymes

41
Q

What are the unwanted effects of benzodiazepines?

A

Sedation
Confusion
Ataxia
Potentiate other CNS depressants (e.g. alcohol)
Tolerance
Dependence
Free plasma concentration of benzodiazepines can be increased by giving aspirin and heparin

42
Q

Name a sedative/hypnotic that isn’t a benzodiazepine. What class of drug does this fall into?

A

Zopiclone – this is a cyclopyrrolone and it’s short-acting (t1/2 = 5 hours)
NOTE: it acts on the benzodiazepine receptor but it is not a benzodiazepine
This has fewer hangover effects but dependency is still an issue

43
Q

What drug is used to control the physical symptoms of anxiety?

A

Propranolol

44
Q

Name a new drug that has started being used as an anxiolytic.

A

Buspirone – 5HT1A agonist
This has relatively few side effects and causes less sedation than benzodiazepines
Downside: slow onset of action (maximal anxiolytic effects are not seen for a number of days/weeks)

Pharmacology (32 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions