4.1. Psychopharmacology - Anti-Depressant's Flashcards
(26 cards)
What are the Indications for the use of Antidepressants?
- Unipolar / Bipolar Depression
- Anxiety Disorders - Including OCD / Panic / Social Phobia / PTSD
- Organic Mood Disorders
- Schizophrenia
How is selection of Antidepressants made?
Efficacy is Similar so:
- Past History of Response
- Side Effect Profile
- Coexisting Medical Condition
With Antidepressants, How long is the Delay (typically) before Symptoms improve?
Therapeutic Dose is achieved (before symptoms improve) after 2-4 weeks
With Antidepressants, When / How should a change in medication be sought?
If there is no improvement seen after a Trial of Adequate Length (at least 2 Months) and Adequate Dose, either Switch to another Agent or Augment with another Agent
What are the Different Classifications of Antidepressants?
- Tricyclic Antidepressants (TCA)
- Monoamine Oxidase Inhibitors (MAOI’s)
- Selective Serotonin Reuptake Inhibitors (SSRI’s)
- Serotonin / Noradrenaline Reuptake Inhibitors (SNRI’s)
- Novel Antidepressants
What are the Features of Tricyclic Antidepressants (TCA’s)?
- Very Effective
- Potentially Unacceptable Side Effect Profile - Anti-Histaminic / Anti-Cholinergic / Anti-Adrenergic
- Lethal In Overdose - Even 1 weeks supply
- Can cause QT Lengthening
What are Tertiary Tricyclic Antidepressants (TCA’s)?
- They have Tertiary Amine Side Chains
2. Side Chains are prone to Cross-React with other types of Receptors - leads to more Side Effects
What are Secondary Tricyclic Antidepressants (TCA’s)?
Metabolites of Tertiary Amine’s which primarily block Noradrenaline
Note - Side effects are the same as Tertiary Tricyclic Antidepressants (TCA’s)
How do Monoamine Oxidase Inhibitors (MAOI’s) work?
They bind Irreversibly to Monoamine Oxidase - preventing inactivation of Amines (Noradrenaline / Dopamine / Serotonin).
This causes an Increase in the Synaptic Levels
Note - These are very effective for resistant depression
What are the Side-Effects of Monoamine Oxidase Inhibitors (MAOI’s)?
- Orthostatic Hypotension
- Weight Gain
- Dry Mouth
- Sedation
- Sexual Dysfunction
- Sleep Disturbance
- Cheese Reaction - Hypertensive Crisis when eating Tyramine-Rish Foods / Sympathomimetics
- Serotonin Syndrome
Note - Wait 2 weeks between switching from SSRI to MAOI
What are the Features of Selective Serotonin Reuptake Inhibitors (SSRI’s)?
- They block the Pre-Synaptic Serotonin reuptake
- Treat both Anxiety and Depressive Symptoms
- Very Little risk of Cardiotoxicity
What are the Side-Effects of Selective Serotonin Reuptake Inhibitors (SSRI’s)?
- Activation Syndrome - gets worse before better
- G.I. Upset
- Sexual Dysfunction
- Anxiety / Restlessness / Nervousness
- Insomnia
- Fatigue / Sedation / Dizziness
- Discontinuation Syndrome
What are the different types of Selective Serotonin Reuptake Inhibitors (SSRI’s)?
- Paroxetine
- Sertraline
- Fluoxitine (Prozac)
- Citalopram
- Escitalopram
- Fluvoxamine
What are the Advantages / Disadvantages of Paroxetine?
Advantages:
- Short 1/2 life with no active metabolites
- Sedation properties
Disadvantages:
- More Anti-Cholinergic Effects - Sedating / Weight Gain
- Likely to cause Discontinuation Syndrome
What are the Advantages / Disadvantages of Sertraline?
Advantages:
- Weak P450 interactions
- Short 1/2 life with lower build-up of metabolites
- Less sedating than Paroxetine
Disadvantages:
- Maximum Absorption requires a Full Stomach
- Increase number of GI Adverse Drug Reaction
What are the Advantages / Disadvantages of Fluoxetine (Prozac)?
Advantages:
- Long 1/2 Life - Less Discontinuation Syndrome
- Initially Activating - Increase Energy
Disadvantages:
- Long 1/2 Life - Active Metabolites may build up
- Significant P450 interactions
- Initial Activation - May increase Anxiety / Insomnia
- More likely to induce Mania than other SSRI’s
What are the Advantages / Disadvantages of Citalopram?
Advantages:
- Low inhibition of P450 Enzymes
- Intermediate 1/2 Life
Disadvantages:
- Dose-Dependent QT interval Prolongation
- Can be Sedating
- GI Side-Effects
What are the Advantages / Disadvantages of Escitalopram?
Advantages:
- Low inhibition of P450 Enzymes
- Intermediate 1/2 Life
- More effective than Citalopram in cute setting
Disadvantages:
- Dose-Dependent QT interval Prolongation
- Nausea / Headache
What are the Advantages / Disadvantages of Fluvoxamine?
Advantages:
- Shortest 1/2 Life
- Has some Analgesic Properties
Disadvantages:
- Shortest 1/2 Life
- G.I. Distress / Headaches / Sedation / Weakness
- Strong inhibitor of some P450 Enzymes
What are the Features of Serotonin / Norepinepherine Reuptake Inhibitors?
- Inhibits Serotonin and Noradrenergic Reuptake - Like TCA’s but without the Side-Effects
- Used for Depression / Anxiety / (Possibly) Neuropathic Pain
What are the Different Types of Serotonin / Norepinephrine Reuptake Inhibitors?
- Venlafaxine
2. Duloxetine
What are the Advantages / Disadvantages of Venlafaxine?
Advantages:
- Minimal Drug Interactions / No P450 Activity
- Short 1/2 Life + Fast Renal Clearance
Disadvantages:
- Increase in Diastolic Blood Pressure
- Nausea
- Discontinuation Syndrome
- QT Prolongation
- Sexual Side-Effects
What are the Advantages / Disadvantages of Duloxetine?
Advantages:
- Efficacy for the Pysical Symptoms of Depression
- Less Blood PRessure increase, compared to Venlafaxine
Disadvantages:
- P450 inhibitor
- Cannot Break Capsule - active ingredient not stable in the stomach
- Higher Drop-Out Rate
What are the types of Novel Antidepressants?
- Mirtazapine
2. Buproprion
