Antidepressants Flashcards
Depression is associated with decreases in
Serotonin, norepinephrine, and dopamine
Most antidepressants increase levels of
Serotonin, NE, and DA
The anti-histamine effects of antidepressants often causes
Sedation and dry mouth
An NE blockade can cause
Hypotension (alpha-1)
Results in tachycardia and urinary retention
Muscarinic blockade
Old antidepressants that blocked reuptake of 5-HT and NE
Tricyclic Antidepressants (TCAs)
Is a broad spectrum antidepressant with anti-histaminergic, anti-muscarinic, and alpha-1 blocking properties
TCA’s
What are the three anti-histaminergic side effects of TCAs?
Sedation, weight gain, confusion (especially in elderly)
What are the 4 anti-muscarinic (anti-cholinergic) effects of TCAs
Blurry vision, constipation, dry mouth, and urinary retention
When a patient is taking TCAs, we need to monitor ECG for
Increased QRS interval
Block cardiac sodium channels
TCAs
The most prominent manifestation of TCA toxicity
Increased QRS interval
What is the treatment for TCA overdose?
- provides excess Na+
- also increased pH favors inactive form of drug
Sodium bicarbonate
Also used for OCD, diabetic neuropathy, chronic pain, and prevention of migraines
TCAs
Inhibits monoamine oxidase, which decreases the breakdown of monoamines
MAO inhibitors
Responsible for the breakdown of dopamine, serotonin, and norepinephrine
MAO-A
Responsible fo the breakdown of Dopamine only
MAO-B
Tranylcypromine, phenelzine, and isocarboxazid are the three forms of
Non-selective MAO inhibitors
Rarely used in the modern era, but can be used for refractory depression and anxiety
MAO inhibitors
An MAO-B selective inhibitor that is used in Parkinson’s
Selegilline
Often caused by MAOi plus another serotonin drug
Serotonin syndrome
If an MAOi is given with any drug that increases serotonin activity, we can see
Serotonin syndrome
Naturally occurring monoamine that causes sympathetic activation
Tyramine
Patients on MAOI’s have tyramine in the blood and can have a hypertensive crisis if they eat
Cheese, red wine, some meats
“Cheese effect”
Inhibits 5-HT reuptake by neurons
-leads to increased 5-HT in synaptic cleft
SSRIs
how long does it take for SSRIs to have their effect?
4-8 weeks
A major side effect of SSRIs is
-Due to increased serotonin effects in the spinal cord
Sexual dysfunction
Commonly cause GI upset, drowsiness, and weight gain
SSRIs
Inhibits 5-HT AND NE reuptake by neurons
-takes 4-8 weeks to have effects
SNRIs
SNRI used in fibromyalgia
Duloxetine
SNRI used in diabetic neuropathy
Venlafaxine
Due to it’s NE effects, SNRIs may increase
Blood Pressure
The SNRI with the highest rate of sexual dysfunction is
Venlafaxine
Blocks reuptake of NE and dopamine and increased presynaptic release of catecholamines
Bupropion
Bupropion has no effects on
Serotonin
Used in depression and smoking cessation
-May improve sexual dysfunction of SSRIs
Bupropion
Bupropion toxicity is related to its stimulant effects and results in
Anxiety, insomnia, and seizures
Blocks PREsynaptic alpha-2 receptors resulting in more norepinephrine and serotonin release
Mirtazapine
Mirtazapine also blocks
POSTsynaptic 5-HT2 and 5-HT3 serotonin receptors
Has anti-histamine side effects such as sedation, dry mouth, and increased appetite
Mirtazapine
Trazodone, vilazodone, and vortioxetine are the three
-Minimal effects on NE or DA
Serotonin modulators
Weak serotonin reuptake inhibitor
-affects 5-HT2A and 5-HT2C receptors
Trazodone
No longer used as an antidepressant and its main clinical use is insomnia
Trazadone
Partial agonist at postsynaptic 5-HT1A receptors
-blocks reuptake of serotonin
Vilazodone
Can cause diarrhea (28%), sexual dysfunction, and serotonin syndrome
Vilazodone
Functions as a full and partial agonist and antagonist of various serotonin receptors
Vortioxetine
