Psychopharmacology Flashcards
What are the four major categories of antidepressants?
- Tricyclic antidepressants (TCAs)
- Monoamine oxidase inhibitors (MAOIs)
- Selective serotonin reuptake inhibitors (SSRIs)
- Atypical antidepressants
- What are the two most common agents to treat major depression?
SSRIs and atypical antidepressants
The choice of a particular medication used for a given patient should be made based on…
- Patient’s symptoms
- Previous treatment responses by the patient or a family member to a particular drug
- Medication side effect profile
- Comorbid conditions
- Risk of suicide
What is the MOA of TCAs?
Inhibit the reuptake of NE and serotonin, increasing availability in the synapse
Why are TCAs rarely used as first-line agents?
Higher incidence of side effects, require greater monitoring of dosing, and can be lethal in overdose
What are some common TCAs?
- Imipramine
- Amitryptiline
- Trimipramine
- Nortriptyline
- Despiramine
- Clomipramine
- Doxepin
What is the treatment for TCA overdose?
Sodium bicarbonate
What are the side effects of TCAs?
(Anti-HAM)
- AntiHistaminic properties: sedation
- AntiAdrenergic properties (CV SE): orthostatic hypotension, tachycardia, arrhythmias
- AntiMuscarinic efects: dry mouth, constipation, urinary retention
- Weight gain
- Lethal in overdose (assess suicide risk)
What are the major complications of TCAs?
3Cs
- Convulsions
- Coma
- Cardiotoxicity
What is the mechanism of action of MAOIs?
Prevent the inactivation of biogenic amines such as NE, serotonin, dopamine, and tyramine by irreversibly inhibiting the enzymes MAO-A and -B
Increase the amount of these transmitters in synapses
When are MAOIs considered very effective?
For certain types of refractory depression and in refractory panic disorder
What are some examples of MAOIs?
- Phenelzine (Nardil)
- Tranylcypromine (Parnate)
- Isocarboxazid (Marplan)
What are the common SE of MAOIs?
- Orthostatic hypotension
- Drowsiness
- Weight gain
- Sexual dysfunction
- Dry mouth
- Sleep dysfunction
What is serotonin syndrome? What antidepressants can cause it?
Occurs when SSRIs and MAOIs are taken together
Characterized by lethargy, restlessness, confusion, flushing, diaphoresis, tremor, and myoclonic jerks
May progress to hyperthermia, hypertonicity, rhabdomyolysis, renal failure, convulsions, coma, and death
How can MAOis lead to hypertensive crisis?
When MAOIs are taken with tyramine-rich foods or sympathomimetics - causes a buildup of stored catecholamines
What is the MOA of SSRIs?
Inhibit presynaptic serotonin pumps, leading to increased availability of serotonin in synaptic clefts
What advantages do SSRIs have over other antidepressants?
- Low incidence of side effects
- No food restrictions
- Much safer in overdose
What are some examples of SSRIs?
- Fluoxetine (Prozac)
- Sertraline (Zoloft)
- Paroxetine (Paxil)
- Fluvoxamine (Luvox)
- Citalopram (Celexa)
- Escitalopram (Lexapro)
Which SSRI has the longest half life?
Fluoxetine
Which SSRI is the most activating (stimulating) and most serotonin specific?
Paroxetine
Which SSRI has the highest risk for GI disturbances?
Sertraline
What are the side effects of SSRIs?
- Sexual dysfunction (25-30%)
- GI disturbance
- Insomnia
- Headache
- Anorexia, weight loss
- Serotonin syndrome when used with MAOIs
What are the types of atypical antidepressants?
- Serotonin/NE reuptake inhibitors (SNRIs)
- NE/Dopamine reuptake inhibitors (NDRIs)
- Serotonin antagonist and reuptake inhibitors (SARIs)
- NE and serotonin antagonists (NASAs)
What type of atypical antidepressant is Venlafaxine (Effexor)? When is it especially useful? When should it not be used?
- SNRI
- Especially useful in treating refractory depression and CAP
- Can increase BP; do not use in patients with untreated or labile BP
What type of atypical antidepressant is Bupropion (Wellbutrin)?
When is Bupropion commonly used?
What is its most significant advantage over SSRIs?
- NDRI
- Commonly used to aid in smoking cessation, and also useful in the treatment of SAD and adult ADHD
- Most significant advantage over SSRIs is relative lack of sexual side effects
What SE are seen with Bupropion at high doses?
When is Bupropion contraindicated?
- Side Effects
- Similar to SSRIs
- Increased sweating and increased risk of seizures and psychosis at high doses
- Not optimal for patients with significant anxiety
- Contraindicated in patients with seizure or active eating disorders and those currently on MAOI
What type of atypical antidepressant are Nefazodone and Trazodone?
When are they especially useful?
- SARIs
- Especially useful in treatment of refractory major depression, major depression with anxiety and insomnia
What are some side effects of SARIs?
Nausea, dizziness, orthostatic hypotension, cardiac arrhythmias, sedation, and priapism (Trazadone)
What type of atypical antidepressant is Mirtazapine?
When is it useful?
- NASA
- Useful in treatment of refractory major depression, especially in patients who need to gain weight
What are some side effects of the NASAs?
- Sedation
- Weight gain
- Dizziness
- Somnolence
- Tremor
- Agranulocytosis
At what dose do you reach the maximal sedative effect of Mirtazapine? What happens at higher doses?
Maximum sedative effect at doses 15 mg and less; at higher doses, it increases NE uptake and is therefore less sedating