Pharmacology of Depression Flashcards
What is Losartan?
Angiotensin 2 receptro blocker
What symptoms does the patient present with?
Feeling low recently Anhedonia Low self-esteem Difficulty getting to sleep Unable to think clearly Fog in head
How are the symptoms affecting his life?
Strain on relationship with wife
Affects performance at work
What is the PHQ-9?
Nine item questionnaire designed to screen for depression in primary care
What is Major Depressive Disorder?
Catch all term including minor, moderate and severe depression
What are the therapeutic objectives for the patient?
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
What is the mechanism of action of SSRIs?
Inhibition of serotonin reuptake results in an accumulation of serotonin.
What are the three most commonly prescribed SSRIs?
Sertraline
Citalopram
Fluoxetine (Prozac)
What is the role of Serotonin?
Serotonin in the central nervous system plays a role in the regulation of mood, personality, and wakefulness
What are the steps when looking at mechanism of action of a drug?
Target
Location
Effect
Why must you consider what other drugs a patient is taking?
Drug interaction can be severe
E.g. severe interaction between Citalopram and Erythromycin
What heart problem is associated with Citalopram?
Torsade de pointes
‘Twisting of peaks’
Can lead to sudden cardiac death
How dose SSRI effectiveness relate to dose?
Peaks at 30mg after this a higher dose does not equate to a better outcome
How do dropouts of a study due to adverse effects relate to SSRI dose?
Increase dose associated with greater dropouts due to adverse effects. Even at optimum dose there are a number of dropouts
How can the plateau in SSRI effectiveness with dose be explained?
Receptor saturation
Why would a GP recommend tapering off the drug?
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
What are two other regularly prescribed anti-depressants?
Venlafaxine
Mirtazapine
What are the transporters involved in the mechanism of venlafaxine?
Inhibitor for two drug targets
Noradrenaline transporter
Serotonin transporter
What is the mechanism of Mirtazapine?
Antagonist of 4 drug targets Alpha 2 receptor Histamine H1 receptor 5HT2 receptor 5HT3 receptor
What are some side effects of venlafaxine?
May contribute to hypertension
How can Mirtazapine impact sleep?
It modestly suppresses REM sleep whilst still having a beneficial impact on sleep continuity and duration die to its anti H1 receptor effect
Is Mirtazapine a selective drug?
No
Acts on 4 different receptors
How will Mirtazapine’s different affinity for the receptors influence its effects?
Sedative effects before it gives you anti-emetic effects
Why does Mirtazapine have no efficacy?
Its an antagonist can only block
