Antidepressants

Question 1

SSRIs:
What are their indications?

Answer 1

First line for moderate to severe depression
Panic disorder
OCD

Question 2

SSRI:
What is their mechanism of action?

Answer 2

They inhibit the reuptake of serotonin from the synaptic cleft
Thereby increasing availability for neurotransmission.

They have fewer side effects and less dangerous in overdose than TCA

Question 3

SSRI:
What are common side effects?

Answer 3

GI upset
Weight/appetite loss/gain
Hypersensitivity reactions
Hyponaetremia: old people which may present as confusion and reduced consciousness
Suicidal thoughts and behaviour
Prolong QT INTERVAL
Increase risk of bleeding
Serotonin syndrome (if taken along side other serotonergic drugs -tramadol)

Question 4

SSRI:
What can sudden withdrawal cause?

Answer 4

GI upset
Neurological and flu like symptoms
Sleep disturbances

Question 5

SSRI:
What group of people would you need to take caution over

Answer 5

Epilepsy
Peptic ulcer disease
Young people (poor efficacy and increased risk of self harm and suicide)
Hepatic impairment

Question 6

SSRI:
What are common interactions?

Answer 6

MAOI
Serotoninergic drugs
Bleeding risk if with anticoagulants, or NSAIDS
Drugs that prolong the QT interval

Question 7

FOR ALL ANTIDEPRESSANTS:
When should symptoms be reviewed after starting?

How is it stopped and why?

How long should treatment last?

Answer 7

1-2 weeks after starting treatment and regularly after. If no effect is seen after 4 weeks consider changing dose or drug. Otherwise dose should be adjusted after 6-8 weeks

Gradually reduced over 4 weeks to minimise withdrawals and relapse

At least 6 months after resolution of symptoms and 2years for recurrent depression

Question 8

SSRI:
What SSRI can be stopped abruptly?

Answer 8

Fluoxetine

Question 9

SSRI
what’s an uncommon indication

Answer 9

Manage menopausal symptoms in women who have breast cancer that suppresses ovarian function

NOT-fluoxetine
Paroxetine

Question 10

SNRI/tetracyclic antidepressants:

What are they indicated for?

Answer 10

major depression
GAD (venlafaxine, duloxetine)
diabetic neuropathy (duloxetine)
Duloxetine can also be used in neuropathic pain acts by increasing pre-synaptic conc in spinal inhibitory pathways.

Question 11

SNRI/TETRACYCLINES :
What is its mechanism of action?

Answer 11

SNRI: interferes with uptake of serotonin-noradrenaline from synaptic cleft

Tetracyclic antidepressant:
antagonises inhibitory pre-synaptic alpha2-adrenorecptors.

Both increase monoamines for neurotransmission- improving mood and physical symptoms.

Tetracyclic AD:
MIRTAZAPINE

SNRI:
Venlafaxine, duloextine

Question 12

SNRI:

What are common side effects and why?

Answer 12

Antimuscarinic side effects due to them being weak antagonists of muscurinic and histamine 1 receptors

tetracyclic ad: potent antagonist of histamine 1 receptors only

Question 13

SNRI/TETRACYCLIC ANTIDEPRESSANTS:

What are important adverse events for both?

Answer 13

GI upset
dry mouth
neurological effects (Confusion, convulsions, abnormal dreams, headache, insomnia)
suicidal thoughts and behaviour
Less common:
hyPOnaetremia
SS

Sudden withdrawal can cause- neurological and flu like symptoms, GI upset and sleep disturbances

Question 14

TETRACYCLIC AD:
What are side effects unique to it

Answer 14

bone marrow suppression

Question 15

SNRI:
what are side effects unique to it?

Answer 15

can cause QT prolongation- increase risk of ventricular arrhythmias
greater risk of withdrawal effects

Question 16

SNRI/TETRACYCLIC ANTIDEPRESSANTS:

What group of people would you be cautious in prescribing these classes?

Answer 16

Older people
renal impairment-dose reduction (duloxetine avoided in severe renal impairment)
risks of arrhythmias( venlafaxine avoided/caution)

Question 17

SNRI/TETRACYCLIC ANTIDEPRESSANTS:
What are important interactions?

Answer 17

similar classes of AD that can increase risk of adverse reactions-
SS

Question 18

SNRI/TETRACYCLIC ANTIDEPRESSANTS:

What is treatment dose of duloxetine for neuropathic pain?

Answer 18

duloxetine 60mg oral daily

Question 19

TETRACYCLIC ANTIDEPRESSANTS:

When should mirtazipine be taken and why?

Answer 19

at night to avoid sedative effects

Question 20

TETRACYCLIC ANTIDEPRESSANTS:
Why should a HCP be worried if a patient develops sore throat whilst on mirtazipine?

Answer 20

a symptoms of an infection could suggest bone marrow suppression.

Question 21

TRICYCLIC ANTIDEPRESSANTS:

What are common indications?

Answer 21

Second line to moderate and severe depression

neuropathic pain

IBS- if antispasmodic

Migraine prophylaxis- amitriptyline

Question 22

TRICYCLIC ANTIDEPRESSANTS:

What is their mechanism of action?

Answer 22

-inhibit serotonin and noradrenaline reuptake from synaptic cleft.

-Increase noradrenaline conc in descending spinal inhibitory pathways.

-Block muscarinic, histamine, alpha adrenergic, dopamine receptors- which is what causes adverse side effects.

Question 23

TRICYCLIC ANTIDEPRESSANTS:

What are common side effects?

Answer 23

dry mouth
urinary retention
blurred vision
exacerbate cognitive impairment
sedation and hypotension- caused by blocked of histamine and adrenergic receptors
arrhythmias
ECG changes (QT prolongation and QRS duration)
seizures
hallucinations
mania
breast changes and sexual dysfunction, extrapyramidal effects ( blocking of D receptors)

Question 24

TRICYCLIC ANTIDEPRESSANTS:

Why are they more dangerous than other AD in overdose?

Answer 24

Can cause life-threatening hypotension, arrhythmias, seizures, coma, respiratory failure

Question 25

TRICYCLIC ANTIDEPRESSANTS:
Which patients need caution required on this medication

Answer 25

older people
epilepsy
CVD
Due to antimuscarinic effects may worsen- constipation, glaucoma, urinary symptoms die to prostate enlargement.

Question 26

TRICYCLIC ANTIDEPRESSANTS:
What are important interactions?

Answer 26

MAOIs
Can cause antimuscarinic effects of other drugs.

Question 27

TRICYCLIC ANTIDEPRESSANTS:

What are starting dosages for all indications.

Answer 27

Depression:
75mg daily

IBS/Neuropathic:
10mg daily