Antidepressants CNS

Question 1

Biological basis of depression

Answer 1

Monoamine hypothesis = in depression , there is a deficit in function of the amount of monoamines (eg : amine neurotransmitter, nor adrenaline and serotonin ) in the brain which stands central to the biology of depression

Question 2

M/A of TCA / Amitriptyline

Answer 2

Amitryptiline ==> blocks reupatke of NT(NA , serotonin ) in the presynaptic nerve terminal ==> NT in the synaptic cleft ==> Action in NT==> Antidepressanr action

2) blocking of receptors action ( muscarinic , histaminergic action )==> antidepressant action

Question 3

Clinical uses of amitriptyline

Answer 3

Depression
Panic disorder
Obsessive compulsive disorder
School phobia
Attention deficit disorder
Bulimia
Chronic pain
Nocturnal enuresis
Premature ejaculation

Question 4

A/E of amitriptyline are

Answer 4

Sedation
Dry mouth and skin
Cardiac arrhythmia
Sexual dysfunction
Weight gain
Constipation
Blurred vision
Urinary retention

Question 5

Non depressant uses of amitriptyline

Answer 5

Sedation
Headache
Chronic pain
Nocturnal enuresis
Premature ejaculation
Bulimia
Attention deficit disorder

Question 6

Compare SSRI with TCA

Answer 6

SSRI = Blocks only serotonin receptor , well absorbed and more bioavailability , long plasma half life , no sedation , no antimuscarinic and cardiovascular effects , no effects on libido

TCA = blocks both NA and serotonin receptor , incomplete absorbed or less bioavailability, short plasma half life , Sedative , more antimuscarinic and cardiovascular effects , decrease libido

Question 7

A/e of SSRI

Answer 7

Decrease libido
Sexual dysfunction
GIT symptoms = transient nausea , diarrhea
CNS Symptoms = anxiety , insomnia
Teratogenecity
Suicidal tendency

Question 8

Advantage of SSRI over TCA

Answer 8

Pharmacokinetic advantage = Absorbed well and thus bio availability is more. No more 1st pass metabolism , long half life thus less frequent dosing

Pharmacodynamic advantage = block only 5HT receptor
No 1) Antimuscarinic , antiadrenergic ,anti histamine blocking adverse effect

Question 9

Anti depressant drugs are

Answer 9

1)Tricyclic antidepressants ( TCA)
1st gen ==> Amitriptyline ,Nortriptyline , protriptyline , Imiprenam, Desiprenam , Clomipramine , Trimipramne
2nd gen ==> Amoxapine , Trazodone , Maprotyline , Bupropion
3rd gen ==> Mirtazapine ,venlafaxine

2)Selective serotonin re uptake inhibitors (SSRI)
Sertraline , Fluoxetine , Paroxetin , Dapoxentine , Citalopram , Escitalopram

3)MAO inhibitors
Selegiline , Phenelzine

4)Selective noradrenaline reuptake inhibitors
Reboxetine