Chapter 19- Anxiolytics Flashcards
1
Q
Why do we need other anxiolytics?
A
- similarites to alcohol and barbiurates without high misuse potential
- higher efficacy
- minimal potential for overdose
2
Q
How many benzo types have been synthesized, and how many are used clinically?
A
- > 3000 synthesized
- 3 dozen used clinically
3
Q
What is the most popular benzo?
A
Diazepam (Valium)
4
Q
What is the most commonly prescribed benzo?
A
alprazolam (xanax)
5
Q
Uses for benzos
A
- sedative/hypnotic effects similar to barbiturates
- effective anticonvulsants
- muscle relaxants
- reduce aggressive tendencies
- decrease anxiety
5
Q
other benzos
A
- chlordiazepoxide (librium)
- oxaepam (serax)
- clorazepate (tranzene)
- Lorzaepam (ativan)
6
Q
Why are benzos better than barbiturates?
A
- more specific than barbiturates and smiliar compounds
- high therapeutic window
- works on he limbic system
- not effective as general anesthetics
- complex array of pharmacology
6
Q
How often do benzos work?
A
- 70-80% of patients
- less likely in individuals with chronic dissatisfaction, insecurit, and/or characer disorders (ex. antisocial personality)
7
Q
Barbituates and benzos mechanisms of action
A
- increase function of the GABA system
- Positive allosteric modulator (PAM) of the GABA-A receptor (increases agonist affinity and/or efficacy)
8
Q
What are GABA-A receptors?
A
the major inhibitory receptors in the brain
9
Q
GABA-A receptor structure
A
- heteromeric ligand-gated ion channels
- 2a’s 2 b’s 1 accessory
- similar in structure to nicotinic acetylcholine receptors
- permeable to chloride ions (negatively charged)
10
Q
What do Barbs and BZa increase? how?
A
- increase chloride currents by binding to allosteric sites
- this hyperpolarizes neurons
11
Q
Where do barbiturates bind?
A
between a and B subunits
12
Q
Where do benzos bind?
A
- between a and y subunits
13
Q
What do BZs act on regarding reinforcement?
A
- they act to suppress the negative reinforcement (stress) network
14
Q
GABA-A Receptor Ligands: GABA
A
- function: main activator
- agonist: GABA, Muscimol
- antagonist: Bicuculline
15
Q
GABA-A Receptor Ligands: Benzos
A
- function: allosteric modulator
- agonist: diazepam, Ro15-4513 (inverse agonist)
- antagonist: flumazenil
16
Q
GABA-A receptor ligands: Barbituarate
A
- function: allosteric modulator
- agonist: phenobarbital
17
Q
GABA-A receptor ligands: neuroactive steroids
A
- allosteric modulator
- agonist: progesterone, pregnanolone, allopregnanolone
