Psychopharmacology - Part 1

Question 1

What is the general guidelines for antidepressant use?

Answer 1

Efficacy is similar
Selection on side effect profile and coexisting medical conditions
Delay of 2-4 weeks
Switch after 2 months if no improvement seen

Question 2

What are the indications for antidepressants?

Answer 2

Unipolar and bipolar depression, organic mood disorders, schizoaffective disorder, anxiety disorders including OCD, panic, social phobia and PTSD

Question 3

What are the classifications of antidepressants?

Answer 3

SSRIs
Tricyclics TCAs
Monoamine oxidase inhibitors MAOIs
SNRIs
Novel antidepressants

Question 4

Describe SSRIs

Answer 4

Block presynaptic serotonin reuptake
Treat both anxiety and depression
Very little risk to cardiotoxicity in overdose

Question 5

What are the side effects of SSRIs?

Answer 5

GI upset, sexual dysfunction, anxiety, restlessness, nervousness, insomnia, fatigue and dizziness

Question 6

What is discontinuous syndrome?

Answer 6

On SSRIs
Agitation, nausea, disequilibrium and dysphoria

Question 7

What is activation syndrome?

Answer 7

On SSRIs
Increased serotonin
Nausea, anxiety, panic and agitation
Typically 2-10 days
Can be distressing for the patient

Question 8

What are the pros of fluoxetine?

Answer 8

Long half life so decreased incidence of discontinuation syndrome
Initially activating so may provide increased energy
Can give one tablet to taper someone off SSRIs

Question 9

What are the cons of fluoxetine?

Answer 9

Long half life and active metabolite may build up
Significant P450 interactions so not good if on a number of meds
More likely to induce mania
Initial activation syndrome

Question 10

What are the pros of sertraline?

Answer 10

Very weak P450 interactions
Short half life with lower build up of metabolites
Less sedating

Question 11

What are the cons of sertraline?

Answer 11

Max. absorption requires full stomach
Increased number of GI side effects

Question 12

Describe TCAs

Answer 12

Very effective but potentially unacceptable side effect profile - antihistamine, anticholinergic and antiadrenergic
Lethal in overdose
Can cause QT lengthening

Question 13

Describe tertiary TCAs

Answer 13

Amine side chains
Prone to cross with other types of receptors which leads to more side effects
Have active metabolites including desipramine and nortiptyline

Question 14

Describe secondary TCAs

Answer 14

Often metabolites of tertiary amines
Primarily block noradrenaline
Side effects are the same as tertiary but less severe
Desipramine and nortriptyline

Question 15

Describe MAOIs

Answer 15

Bind irreversibly to monoamine oxidase so prevent inactivation of amines leading to increased synaptic levels
Effective against resistant depression

Question 16

What are the side effects of MAOIs?

Answer 16

Orthostatic hypertension, weight gain, dry mouth, sedation, sexual dysfunction and sleep disturbance

Question 17

What is the Cheese reaction?

Answer 17

Hypertensive crisis can develop when on MAOIs are taken with tyramine rich foods or sympathomimetics

Question 18

What is serotonin syndrome?

Answer 18

If take MAOIs with meds that increase serotonin or have sympathomimetic actions
Abdominal pain, diarrhoea, sweats, tachycardia, HTN, myoclonus, and delirium
Can lead to hyperpyrexia, cardiovascular shock and death
Wait 2 weeks from switching from SSRIs to MAOI

Question 19

Describe SNRIs

Answer 19

Inhibit both serotonin and NA reuptake but without antihistamine, antiadrenergic and anticholinergic side effects
Used for depression, anxiety and possible neuropathic pain

Question 20

What are the pros of venlafaxine?

Answer 20

Minimal drug interactions
Short half life and fast renal clearance avoids build up

Question 21

What are the cons of venlafaxine?

Answer 21

Can cause a 10-15mmHG dose dependant increase in diastolic BP
Significant nausea
Bad discontinuation syndrome and taper recommended
Sexual side effects

Question 22

What are the pros of duloxetine?

Answer 22

Some efficacy in physical symptoms of depression
Less BP increase

Question 23

What are the cons of duloxetine?

Answer 23

CYP2D^ and CYP1A2 inhibitor
Not stable within the stomach
High drop out rate

Question 24

Describe vortioxetine

Answer 24

SNRI
Less GI side effects and changes in BP
Expensive
Specialists only

Question 25

What are the pros of mirtazapine - novel antidepressant?

Answer 25

Different mechanism of action may provide good augmentation strategy to SSRIs
Can be utilised as a hypnotic

Question 26

What are the cons of Mirtazapine?

Answer 26

Increases serum cholesterol by 20%
Very sedating at lower doses
Can become activating and require change
Associated with weight gain

Question 27

What is the treatment for treatment resistant depressant?

Answer 27

Combination of antidepressants - SSRI or SNRI with mirtazepine
Adjunctive treatment with lithium
Adjunctive treatment with atypical antipsychotic
ECT

Question 28

How do you treat treatment resistant anxiety?

Answer 28

High dose SSRI first
Combination of antidepressants - SSRI or SNRI with mirtazepine
Adjunctive treatment with atypical antipsychotics
Adjunctive treatment with pregabalin or buspirone
Avoid diazepam

Question 29

Describe prophylaxis in depression

Answer 29

First episode continue for 6 months to a year
Second - continue for 2 years
Third - life long