pharmacology of anxiolytic drugs

Question 1

drugs used to treat anxiety

Answer 1

-benzodiazepines
-antidepressant drugs
-buspirone
-pregabalin
-beta blockers

Question 2

where does fear and phobia come from in the brain

Answer 2

amygdala - centered circuit

Question 3

where does anxiety, apprehension and obsessions come from in the brain

Answer 3

cortico-striatal-thalamic-cortical circuit

Question 4

where in the brain is affect of fear

Answer 4

anterior cingulate cortex/orbitofrontal cortex

Question 5

where is avoidance (fight/flight) in the brain

Answer 5

periaqueductal gray

Question 6

endocrine effects of fear

Answer 6

increase in cortisol

Question 7

where is re-experiencing (traumatic memories) created

Answer 7

hippocampus

Question 8

neurotransmitters involved in amygdala centred circuits

Answer 8

5HT (Serotonin)
GABA (Gamma-aminobutyric acid)
Glutamate
CRF (Corticotrophin releasing factor)
NE (Norepinephrine)
Voltage gated ion channels

Question 9

GABA

Answer 9

-Main inhibitory transmitter in the brain
-Reduces activity of neurons in amygdala and CSTC circuit
-Benzodiazepines (anxiolytic) enhance GABA action

Question 10

what are the main GABA receptors

Answer 10

– GABA-A, GABA-B & GABA-C

Question 11

which GABA receptor is the target of benzodiazepines, barbiturates and alcohol

Answer 11

GABA-A

Question 12

benzodiazepines mechanism of action

Answer 12

-Benzodiazepines bind at a separate site to GABA
-Increases the likelihood that GABA binding will activate the receptor and/or increases the effect that GABA has when it binds to the receptor
-Increased frequency of opening allows more chloride to pass through which hyperpolarises the membrane potential and makes it less likely the neuron will fire an action potential

Question 13

pharmacological effects of benzodiazepines

Answer 13

-reduce anxiety and depression
-hypnosis/sedation
-muscle relaxation
-anticonvulsant effect
-anterograde amnesia

Question 14

clinical uses of benzodiazepines

Answer 14

Acute treatment of extreme anxiety
Hypnosis
Alcohol withdrawal
Mania
Delirium
Rapid tranquillisation
Premedication before surgery or during minor procedures
Status epilepticus

Question 15

problems with benzodiazepines

Answer 15

-Paradoxical aggression
-Anterograde amnesia & impaired coordination
-Tolerance and dependence

Question 16

symptoms of benzodiazepine withdrawal

Answer 16

-abdo cramps
-increased anxiety, panic attacks
-physical symptoms
-blurred vision
-depression
-insomnia, nightmares
-dizziness
-headaches
-sweating, shaking
-nausea and vomiting
-inability to concentrate
-tingling in hands and feet
-restlessness
-sensory sensitivity

Question 17

what causes benzodiazepine withdrawal

Answer 17

-Chronic treatment with benzodiazepines ↓ response to GABA
-Withdrawal results in anxiety/convulsions possibly due to ↓ density of benzodiazepine receptors

Question 18

how do you withdraw benzodiazepines

Answer 18

1. Transfer patient to equivalent daily dose of diazepam/chlordiazepoxide preferably taken at night
2. Reduce dose every 2–3 weeks in steps of 2 or 2.5mg; if withdrawal symptoms occur, maintain this dose until symptoms improve
3. Reduce dose further, if necessary in smaller steps; it is better to reduce too slowly rather than too quickly
4. Stop completely; time needed for withdrawal can vary from about 4 weeks to a year or more

Question 19

mechanism of action of SSRI’s

Answer 19

Transporter transports neurotransmitter out of the synaptic cleft into the neuron that released them
SSRI inhibit the reuptake of serotonin leading to increased serotonin in the synaptic cleft

Question 20

how do SSRI’s treat anxiety

Answer 20

increase extracellular serotonin

Question 21

management of GAD

Answer 21

-psychoeducation
-self help/psychoeducation groups
-CBT or SSRI
-SNRI
-pregabalin
-combination of CBT and drug treatment

Question 22

management of panic disorder

Answer 22

-self help
-CBT or SSRI
-tricyclics