03b: GABA-R Flashcards Preview

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Flashcards in 03b: GABA-R Deck (40)
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1
Q

GABA(A) Receptor is (monomer/trimer/pentamer) with which subunits?

A

Pentamer;

alpha, beta, and either gamma or delta

2
Q

(X) number of GABA bind to activate GABA(A) Receptor. (Y) number of benzos bind to modulate.

A
X = 2
Y = 1
3
Q

“Phasic” GABA(A) R location is (X) and has (gamma/delta) subunit.

A

X = at synapse

Gamma

4
Q

“Tonic” GABA(A) R location is (X) and has (gamma/delta) subunit.

A

X = extra-synaptic

Delta

5
Q

T/F: All GABA(A) receptors are responsive to benzos.

A

False - tonic GABA(A) R are not

6
Q

(Tonic/phasic) GABA(A) receptors have very fast response.

A

Phasic (at synapse)

7
Q

Most common GABA(A) receptor subtype.

A

alpha(1)beta(2)gamma(2)

8
Q

Which alpha subunit sbind benzos most efficiently?

A

Alpha(2) and Alpha(3)

9
Q

List the various effects of the Benzos.

A
  1. Anxiolytic action
  2. Sedation/hypnosis and muscle relaxant
  3. Anticonvulsant action
10
Q

T/F: Benzo-like drugs are indicated for alcohol/cocaine withdrawal.

A

True (BUT be careful since benzos plus EtOH can be fatal!!)

11
Q

Benzos are contraindicated in patients with which diseases?

A
  1. COPD
  2. Alcohol abuse
  3. Sleep apnea
12
Q

Benzos should be administered with caution in which patients?

A
  1. Elderly (decrease clearance)
  2. Suicidal (abuse potential)
  3. Lung, liver, kidney disease
13
Q

T/F: Benzodiazepines have replaced barbiturates as sedative-hypnotic drugs.

A

True (safer, higher therapeutic index)

14
Q

T/F: Barbiturates have greater specificity of action in CNS than Benzos.

A

False

15
Q

Benzos are fairly (lipo/hydro)-philic, administered (IV/po) with (slow/quick) onset of CNS effect.

A

Lipophilic;
Both (high bioavailability and safety via p.o.)
Quick (immediate in case of IV)

16
Q

T/F: Benzos are primarily cleared without modification/transformation into metabolites.

A

False - biotransformation (CYP450) into active metabolites

17
Q

T/F: Duration of action of benzos is dependent strictly on the life of the parent drug.

A

False - depends also on active metabolites

18
Q

T/F: Chronic benzos use leads to psych and physical dependence.

A

True

19
Q

T/F: Signs of benzos withdrawal are typically (mild/severe) and worse with (short/long)-acting benzos.

A

Mild (anxiety, sleep issues);

Short

20
Q

T/F: Benzos efficacy is greater than barbiturates.

A

False

21
Q

List the few clinical uses of barbiturates in US.

A

IV: rapid onset/offset anesthesia (thiopental)
PO: intractable seizures in kids (phenobarbital)

22
Q

T/F: Barbiturates act as GABA(A) receptor agonists.

A

True (at high concentrations); thus can act as potentiators or agonsts

23
Q

(X) is the most commonlyused IV general anesthetic in the U.S. It acts as a(n) (Y) receptor (agonist/antagonist/modulator).

A
X = propofol
Y = GABA(A)

Positive modulator (increase affinity of receptor for GABA)

24
Q

Drugs used for simple (no loss of consciousness) seizures. Star the “drugs of choice” (as opposed to the alternatives).

A
  1. Lamotrigine*
  2. Carbamazepine*
  3. Phenytoin
25
Q

Phenytoin mechanism of action. Which drugs work in the same way?

A

Prolongs Na channel inactivation state

Lamotrigine, carbamazepine

26
Q

Drugs used for complex (impaired consciousness) seizures. Star the “drugs of choice” (as opposed to the alternatives).

A
  1. Lamotrigine*
  2. Carbamazepine*
  3. Phenytoin

SAME AS SIMPLE SEIZURES

27
Q

Drugs used for simple (with secondarily generalized tonic/clonic) seizures. Star the “drugs of choice” (as opposed to the alternatives).

A
  1. Lamotrigine*
  2. Carbamazepine*
  3. Phenytoin

SAME AS COMPLEX SEIZURES

28
Q

Drug(s) of choice used for generalized tonic/clonic seizures.

A

Valproate

29
Q

Valproate MOA

A
  1. Enhance GABA transmission (increase its synthesis, inhibits its degradation by GABA transaminase)
  2. Reduce Ca flow through T-type Ca channels
30
Q

Drug(s) of choice used for generalized absence seizures.

A
  1. Ethosuximide

2. Valproate

31
Q

T/F: Benzos are used to generalized (tonic-clonic, absence, myoclonic) seizures.

A

True - Clonazepam is used as “alternative” (not drug of choice)

32
Q

Ethosuximide

A

Reduce Ca flow through T-type Ca channels

33
Q

Drug(s) of choice used for generalized myoclonic seizures.

A
  1. Valproate

2. Lamotrigine

34
Q

Drug(s) of choice for refractory seizures.

A

Benzos (diazepam, lorazepam)

35
Q

Starting epilepsy treatment is typically done after (X) number of unprovoked seizure if it occurs (Y) time after the first.

A
X = 2nd
Y = over 24h
36
Q

T/F: Monotherapy is the gold standard of treatment for epilepsy.

A

True - only a very small percentage of patients cannot be treated with a single drug.

37
Q

What are recommendations regarding switching anticonvulsant drug from brand to generic?

A

Physicians are urged to keep patients on the medication that is currently managing their disease - increased chance of breakthrough seizures if switched to generic

38
Q

List three older AEDs that are used less due to disadvantages such as CYP450 interactions.

A
  1. Carbamazepine
  2. Phenytoin
  3. Valproate
39
Q

(X) is an old AEDs that is used less due to disadvantages such as potentially fatal hepatotoxicity.

A

X = Valproate

40
Q

(X) is an old AEDs that is used less due to disadvantages such as diplopia and ataxia.

A

Carbamazepine and Phenytoin