Anxiolytics

Question 1

Symptoms of anxiety

Answer 1

Difficulty with sleep
Tiredness
Heart palpitations 
Headache
Nausea
Sense of dread
Stress and worry

Question 2

SSRIs

Answer 2

Citalopram (causes long QT), fluoxetine (in children) and sertraline
Side effects = GI bleeding and drug interactions with warfarin
Gradually reduce over 4 weeks

Question 3

SSRI MOA

Answer 3

Block re-uptake of serotonin
Serotonin regulated by -ve feedback cycle - more serotonin in cleft means less is released
Inhibition of serotonin uptake temporarily increases extracellular serotonin but increases serotonin inhibition so no net change
Lots of serotonin exposure means receptors desensitise = more serotonin

Question 4

Benzodiazepines

Answer 4

Diazepam, lorazepam, alprazolam
Used in sedation, hypnosis and for anxiety
Increase the frequency of Cl- channels
To withdraw, switch to citalopram and withdraw very slowly
Withdrawal sx = anxiety, tremor, respiratory acidosis etc
Quick acting - used as bridging therapy

Question 5

Barbituate and benzodiazepine action on GABA

Answer 5

Barbituates increase duration of Cl- channel opening

Benzodiazepines increase frequency of Cl- channels

Question 6

GABAa agonists

Answer 6

Pregabalin

Question 7

SNRI MOA

Answer 7

Inhibition of NA reuptake = desensitisation of NA receptors which increases NA levels

Question 8

B blockers and anxiety

Answer 8

Propanolol
Competitive antagonist that blocks sympathetic NS effects
Act upon GPCRs to release adenylate cyclase to activate B1 (increased HR) and B2 (smooth muscle relaxation and tremor)