Antidepressants

Question 1

Mechanism of action of SSRIs

Answer 1

1. Inhibits reuptake of serotonin.
2. Causes an increased concentration in the synapse
3. Takes several weeks to have full effect

Question 2

Clinical indications for SSRIs

Answer 2

1. Depression
2. Anxiety disorders e.g. GAD, OCD & PTSD

Question 3

Side effects of SSRIs

Answer 3

1. agitation
2. sexual dysfunction
3. nausea
4. diarrhoea
5. dizziness
6. headaches
7. insomnia

Question 4

Why do SSRIs need to dosed down slowly?

Answer 4

Abrupt withdrawal causes discontinuation syndrome

(dizziness, fatigue, headaches etc)

Question 5

Which SSRI causes a QT prolongation?

Answer 5

Citalopram

Question 6

What is important to tell a patient who is started on an SSRI?

Answer 6

Initially, their symptoms will worsen before it gets better

There is an initial increase in suicide risk in <25 year olds

Question 7

Give 3 examples of SSRIs

Answer 7

1. sertraline
2. fluoxetine
3. citalopram

Question 8

Examples of Tricyclic antidepressants

Answer 8

Amitriptyline, Clomipramine, Imipramine.

Question 9

Mechanism of action of TCAs

Answer 9

Inhibit the re-uptake of sertraline and noradrenaline.
Also act as antagonists and several other neurotransmitter receptors e.g muscarinic, alpha1 and H1.

Question 10

Which TCA is licensced for OCD?

Answer 10

Clomipramine

Question 11

Side effects of TCA

Answer 11

Anticholinergic – dry mouth, urinary retention etc
Drowsiness, headache
Cardiovascular – tachycardia, QT prolongation
Withdrawal effect – nausea, anxiety, sweating, insomnia.

Question 12

What can happen in TCA toxicity/overdose?

Answer 12

cardiac arrhythmias (ventricular fibrillation)
seizures
hypotension

Question 13

Give 3 examples of MAOIs (Monoamine Oxidase Inhibitors)

Answer 13

Phenelzine, Isocarboxazid, Moclobemide

Question 14

Why are MOIs not usually used?

Answer 14

Rarely used now due to interactions with foods and other medications. Reserved for patients who have not responded to other treatments.

Question 15

What condition does a patient who has not responded to medication have?

Answer 15

Refractory (depression or anxiety)

Question 16

What is Mirtazapine?

Answer 16

It is a presynaptic alpha 2 adrenoreceptor antagonist

Question 17

Indication(s) of mirtazapine

Answer 17

used to treat depression and sometimes obsessive compulsive disorder (OCD) and anxiety

Question 18

Examples of SNRIs

Answer 18

Venlafaxine and Duloxetine

Question 19

Indications for SNRIs

Answer 19

Usually second line treatment for depression. Can be used for Generalised anxiety disorder.

Question 20

When are Venlafaxine and Mirtazapine used in combination?

Answer 20

Venlafaxine and mirtazapine in combination are increasingly used in clinical practice to treat treatment-refractory depression. (depression that has not responded to other medications)

Question 21

What food cannot be consumed by someone taking MOAIs?

Answer 21

Cheese
As it contains tyramine
This can cause hypertensive crisis

Question 22

What is the risk of SSRI therapy in third trimester of pregnancy?

Answer 22

There is a risk of persistent pulmonary hypertension of the newborn.