10 Hypnotics and Anxiolytics

Question 1

Anxiety definition and cause

Answer 1

Definition: An emotional disorder characterised by uncertainty, apprehensiveness, and unresolved fear. Can be acute or chronic.
Involves the amygdala, hippocampus, and prefrontal cortex

Cause:

• exaggerated output through the central nucleus of the amygdala to different regions of the brain
• low level of GABA

Question 2

Types of anxiety

Answer 2

1) Generalised anxiety disorder
2) OCD
3) PTSD
4) Phobia
5) Panic disorder
6) Social anxiety disorder

Question 3

Symptoms

Answer 3

Physical: tremor, palpitation, GI disturbance, sweating, weeping, difficulty breathing

Emotional: tension, apprehension, irritability, restlessness, fear, sense of insecurity

Question 4

Types of anxiolytics

Answer 4

1) Benzodiaepine
2) 5HT1A receptor agonist
3) Beta adrenergic blocker
4) Antidepressant
5) Antiepileptic drug
6) Atypical antipsychotic drugs

Question 5

Sedative (anxiolytic) vs. Hypnotic

Answer 5

Sedative (anxiolytic): reduces anxiety and exert a calming effect to the CNS.

Hypnotic:
produces drowsiness and encourages the onset and maintenance of a state of sleep.

Hypnotic effects involve more pronounced depression of the CNS

Question 6

What is GABA?

Answer 6

• synthesized from glutamate
• inhibitory neurotransmitter
• GABA A receptor: ionotropic
  receptors +
  consists of α-, β- and g2-subunits in a 2:2:1 ratio
• GABA B receptor: metabotropic receptors

Question 7

Benzodiazepines

Answer 7

Mechanism:
selectively act on GABA A receptors and enhances inhibitory synaptic transmission in CNS
, cannot function alone without GABA

Effects: sedation, sleep induction at higher concentration, anxiolysis

Side effects: withdrawal symptoms, tolerance (chronic use), physical dependence, acute toxicity in overdose

Addiction due to the lack of GABA inhibition of reward center in brain releasing more dopamine

Drug withdrawal should be done gradually and slowly to avoid increasing anxiety

Question 8

Diazepam, Flurazepam, Nitrazepam

Answer 8

Treat acute anxiety states, emergency treatment

Question 9

Lorazepam

Answer 9

Treat acute anxiety states, epilepsy, and insomnia

Question 10

Midazolam

Answer 10

Treat insomnia, general anesthesia

Question 11

Benzodiazepine antagonist

Answer 11

Mechanism: compete for the receptor that BZD agonists bind to. Used to treat BZD overdose.

Example: flumazenil

Question 12

5 HT1A partial agonist

Answer 12

Mechanism: agonist of auto-inhibitory receptors and desensitises it –> decrease negative feedback–> increase 5HT release

Example: buspirone

Side effects: nausea, dizziness, headache, restlessness

Does not cause sedation and takes week to produce anxiolytic effects

Question 13

Beta adrenergic blocker

Answer 13

Mechanism: non selective beta adrenoceptor blocker

Effect: reduce shaking hands

Question 14

Types of hypnotics

Answer 14

1) Z drugs
2) benzodiazepine

Generally larger dose of anxiolytics work

Question 15

Z drugs

Answer 15

Mechanism: Bind to same modulatory site as BZD on GABA A receptors

No anxiolytic effects

Examples: zopidem, zopiclone

Side effects: tolerance, rebound insomnia