BZD & hypnotics (PSYCH DRUGS)

Question 1

Pt has initial insomnia (ie. Difficulty initiating sleep, cannot fall asleep). BZD of choice?

Answer 1

Diazepam - fast ONSET

Question 2

Pt has middle insomnia (ie. wake up in middle of sleep). BZD of choice?

Answer 2

Lorazepam - slow ONSET

Question 3

Metabolism of BZD?

Answer 3

Hepatic.

Question 4

Diazepam - Onset and elimination half life and potency
Dose?

Answer 4

Onset: fast
Elimination half life: long
Potency: low
Dose: 5-10mg on

Question 5

Lorazepam - onset and elimination half life and potency
dose?

Answer 5

Onset: slow
Elimination half life: short
Potency: high
Dose: 0.5-1mg

Question 6

Clonazepam onset and elimination half life and potency and dose

Answer 6

Onset: slow
Elimination half life: long
Potency: high
Dose: 0.25-0.5mg on

Question 7

Alprazolam onset and elimination half life and potency and dose

Answer 7

Onset: fast
Elimination half life: short
Potency: high
Dose: 0.25mg bd or tds

Question 8

BZD MOA

Answer 8

Facilitate/enhance action of GABA (GABA positive modulator), GABA is an inhibitory neurotransmitter on CNS excitability –> hypnotic, sedative, anxiolytic, anticonvulsant, amnesic and muscle relaxant properties

Question 9

GABA MOA =/ MOA of BZD

Answer 9

GABA binds to GABA receptor on chloride channel –> chloride channel opens –> chloride ion flow into neuron –> inhibit nerve impulse
- Act on limbic system –> decrease anxiety
- Depress reticular activating system of the brain –> induce sleep

Question 10

Side effects of BZD

Answer 10

1. Oversedation
2. Memory impairment (episodic memory type)
3. Dependency
4. Respiratory depression

Question 11

Symptoms of BZD withdrawal

Answer 11

1. Insomnia, panic attacks, tremors (anxiety type)
2. Hyperacusis, perceptual distortions (altered perceptions)
3. Hallucination, delirium, seizures, hyperpyrexia, elevated vital signs

Question 12

Non-BZD hypnotics - dose, onset of action, half life

Answer 12

X2 the Z drugs
1. Zolpidem (dose: 6.25-12.5 mg on, onset: rapid - 10-30mins, half life - 3-4h)
2. Zopiclone (dose: 3.75-7.5mg on, onset: rapid - 15-30mins, half life - 5-6h)

Question 13

Zopiclone, zolpidem Side effects

Answer 13

1. Metallic taste
2. Ataxia
3. Risk of Dependence

Question 14

Zopiclone, zolpidem MOA

Answer 14

Works by GABA pathway as well, but chemically diff from BZD