Pharmacology Flashcards
What are the Selective Serotonin Reuptake Inhibitors (SSRI’s) available?
- Citalopram
- Escitalopram
- Paroxetine
- Fluoxetine
- Fluvoxamine
- Sertraline
What is the mechanism of action of SSRI’s?
What is the PK of SSRI’s?
Selectively inhibits CNS uptake of seratonin, leading to increased seratonin activity in the CNS
Exclusively metabolized in the liver
What are the indications of SSRI’s?
First line medical therapy for depression (MDD), PTSD, panic disorder, premenstrual dysphoric disorder, and anxiety disorder
What is the only antidepressant approved for the treatment of bulimia?
Flouxetine
The half-life of SSRI’s is about 24 hours with the exception of what SSRI which is much longer?
Why is this important?
Fluoxetine has a half life of 2-4 days
Need to consider washout period for switching to MAOIs
On average, on long do SSRI’s take to reach maximum efficacy?
4-6 weeks
What are the adverse side effects of SSRI’s?
- GI: nausea and diarrhea
- Headache, fatigue, restlessness, insomnia
- Sexual dysfunction (decrease libido, anorgasmia)
- Increased suicidality in children and young adults
What black box warning has been given to SSRI’s?
Increased suicidality in children and young adults
Which SSRI should be avoided in patients with long QT syndrome?
Citalopram
What are the serotonin and norepinephrine reuptake inhibitors (SNRI’s)?
What is the MOA?
- Duloxetine
- Venlafaxine
- Desvenlafaxine
inhibits reuptake of 5-HT, NE, and DA
What are the indications of SNRI’s?
- Duloxetine may be used as a first line agent, particulary in patients with fatigue or neuropathy pain syndromes in association with depression
- Venlafaxine is good for depression and anxiety disorder or a depressive episode in Bipolar patients
What electrolyte imbalance is associated with SSRI’s and SNRI’s?
Hyponatremia
The side effects of SNRI’s are similar to those of SSRI’s. But where SNRI’s block the reuptake of norepinephrine what additional side effects are seen?
Norepinephrine effects including hypertension, sweating, dizziness, dry mouth, and constipation
What are the contraindications and cautions associated with SNRI’s?
- MAOI use
- Renal or hepatic impairment
- Siezures
- Avoid abrupt discontinuation
- Use with caution in patients with hypertension
- Increased risk of seratonin syndrome with SNRI + St. John’s Wort
What is the MOA of Mirtazapine?
Atypical Tetracyclic Antidepressant
Increases the release of NE and 5-HT via central presynaptic alpha-2 adrenergic receptor antagonism. High affinity for histamine H1 receptors (leading to its sedative properties)
