Pharmacology of Depression

Question 1

What is Losartan?

Answer 1

Angiotensin 2 receptro blocker

Question 2

What symptoms does the patient present with?

Answer 2

Feeling low recently
Anhedonia
Low self-esteem
Difficulty getting to sleep
Unable to think clearly
Fog in head

Question 3

How are the symptoms affecting his life?

Answer 3

Strain on relationship with wife

Affects performance at work

Question 4

What is the PHQ-9?

Answer 4

Nine item questionnaire designed to screen for depression in primary care

Question 5

What is Major Depressive Disorder?

Answer 5

Catch all term including minor, moderate and severe depression

Question 6

What are the therapeutic objectives for the patient?

Answer 6

Alleviate depressive symptoms:
Improve mood/restore ability to feel pleasure
Help with sleep difficulties
Improve hid esteem
Improve his ability to think clearly 

Reduce likely functional impairment depressive symptoms have on his daily life:

Improve relationship with wife
Improve performance in job

Question 7

What is the mechanism of action of SSRIs?

Answer 7

Inhibition of serotonin reuptake results in an accumulation of serotonin.

Question 8

What are the three most commonly prescribed SSRIs?

Answer 8

Sertraline

Citalopram

Fluoxetine (Prozac)

Question 9

What is the role of Serotonin?

Answer 9

Serotonin in the central nervous system plays a role in the regulation of mood, personality, and wakefulness

Question 10

What are the steps when looking at mechanism of action of a drug?

Answer 10

Target
Location
Effect

Question 11

Why must you consider what other drugs a patient is taking?

Answer 11

Drug interaction can be severe

E.g. severe interaction between Citalopram and Erythromycin

Question 12

What heart problem is associated with Citalopram?

Answer 12

Torsade de pointes
‘Twisting of peaks’
Can lead to sudden cardiac death

Question 13

How dose SSRI effectiveness relate to dose?

Answer 13

Peaks at 30mg after this a higher dose does not equate to a better outcome

Question 14

How do dropouts of a study due to adverse effects relate to SSRI dose?

Answer 14

Increase dose associated with greater dropouts due to adverse effects. Even at optimum dose there are a number of dropouts

Question 15

How can the plateau in SSRI effectiveness with dose be explained?

Answer 15

Receptor saturation

Question 16

Why would a GP recommend tapering off the drug?

Answer 16

Withdrawal symptoms
System becomes used to the drug
Risk of drug interactions if starting new drug
Risk of serotonin syndrome
Washout required before starting new drug

Question 17

What are two other regularly prescribed anti-depressants?

Answer 17

Venlafaxine

Mirtazapine

Question 18

What are the transporters involved in the mechanism of venlafaxine?

Answer 18

Inhibitor for two drug targets
Noradrenaline transporter
Serotonin transporter

Question 19

What is the mechanism of Mirtazapine?

Answer 19

Antagonist of 4 drug targets
Alpha 2 receptor
Histamine H1 receptor
5HT2 receptor
5HT3 receptor

Question 20

What are some side effects of venlafaxine?

Answer 20

May contribute to hypertension

Question 21

How can Mirtazapine impact sleep?

Answer 21

It modestly suppresses REM sleep whilst still having a beneficial impact on sleep continuity and duration die to its anti H1 receptor effect

Question 22

Is Mirtazapine a selective drug?

Answer 22

No

Acts on 4 different receptors

Question 23

How will Mirtazapine’s different affinity for the receptors influence its effects?

Answer 23

Sedative effects before it gives you anti-emetic effects

Question 24

Why does Mirtazapine have no efficacy?

Answer 24

Its an antagonist can only block