Antidepressants B&B Flashcards
what are the side effects of TCAs?
- anti-histamine: sedation, weight gain, confusion (elderly)
- anti-muscarinic: blurry vision, constipation, dry mouth, urinary retention
- alpha-1 block: orthostatic hypotension
contrast the 2 groups of TCAs
- tertiary amines (3 N groups): more sedating (anti-histamine); ex - amitriptyline, clomipramine, doxepin, imipramine, trimipramine
- secondary amines (2 N groups): more activity (NE effects); ex - desipramine, nortriptyline, protriptyline
which of the following TCAs would be most appropriate for a patient with depression who is experiencing excessive drowsiness? why?
a. amitriptyline
b. desipramine
c. doxepin
d. imipramine
b. desipramine - secondary amine, which have NE effects (activating)
tertiary amines (all other choices) are sedative due to anti-histamine effects (better for patients having trouble sleeping)
what serious effects (3) can occur if a patient overdoses on TCAs?
- seizures - antagonize GABA
- hyperthermia (due to loss of sweating) - anti-cholinergic
- hypotension/ prolonged QT interval (arrhythmias) - alpha1 blockage
how should patients with TCA overdose be monitored? what is the treatment for TCA overdose?
monitor ECG for increased QRS interval - TCAs block cardiac alpha1 receptors
tx with sodium bicarbonate - extra Na+ overcomes Na+ channel blockage + increased pH favors inactive drug form
for what non-depression uses are TCAs prescribed? 6
- OCD (clomipramine)
- diabetic peripheral neuropathy (amitriptyline, desipramine)
- chronic pain
- migraine prophylaxis (amitriptyline)
- bed wetting (enuresis) - 2nd line after desmopressin
- insomnia (doxepin)
which TCA is used to treat OCD?
clomipramine
which 2 TCAs are used to treat diabetic peripheral neuropathy?
- amitriptyline
- desipramine
which TCA is used for migraine prophylaxis?
amitriptyline
which TCA is used to treat insomnia?
doxepin
MAO-A vs MAO-b inhibitors
give examples of each
MAO-A inhibitors are non-selective - prevent breakdown of dopamine, serotonin, NE (tranylcypromine, phenelzine, isocarboxazid) - treats refractory depression/ anxiety
MAO-B inhibitors only prevent breakdown of dopamine (selegiline) - treats Parkinson’s
name an example of each of the following that can induce serotonin syndrome:
a. illicit substance
b. anti-nausea med
c. migraine treatment
d. antibiotic
e. cough suppressant
f. herbal supplement
a. illicit substance - MDMA (ecstasy)
b. anti-nausea med - ondanestron (5-HT3 antagonist)
c. migraine treatment - triptans (5-HT agonists)
d. antibiotic - linezolid (weak MAO inhibitor)
e. cough suppressant - dextromethorphan (weak SSRI)
f. herbal supplement - St. John’s wart (increases 5-HT activity)
name 7 conditions for which SSRIs are prescribed
- depression
- generalized anxiety
- panic disorder
- OCD
- bulimia
- social anxiety
- PTSD
what is the main side effect of SSRIs?
sexual dysfunction - decreased libido, anorgasmia, ED
due to increased serotonin in spinal cord
name an SNRI used to treat fibromyalgia
duloxetine
name an SNRI used to treat diabetic neuropathy
venlafaxine
what is the MOA and clinical use of bupropion?
blocks reuptake of NE and dopamine (NET/DAT) + increases presynaptic release of catecholamines (NO serotonin effects)
tx depression + smoking cessation, may improve sexual dysfunction of SSRIs (used in combo to cancel out effects)
drug used in smoking cessation which blocks reuptake of NE and dopamine
bupropion: blocks reuptake of NE and dopamine (NET/DAT) + increases presynaptic release of catecholamines (NO serotonin effects)
tx depression + smoking cessation, may improve sexual dysfunction of SSRIs (used in combo to cancel out effects)
what is the MOA (2) and clinical use of mirtazapine?
antidepressant which:
1. blocks presynaptic alpha-2 receptors (decrease in neg. feedback for NE release)
2. blocks postsynaptic 5-HT2 + 5-HT3 receptors
—> increase in NE and serotonin release + increase in 5-HT1 receptor activity (bc the other 2 are blocked)
what side effects are associated with mirtazapine?
antidepressant, blocks presynaptic alpha-2 receptors (decrease in neg. feedback of NE release) + blocks postsynaptic 5-HT2 + 5-HT3 receptors (increased 5-HT1 R activity)
also anti-histamine - causes sedation, dry mouth, increased appetite, weight gain
Pt presents with complaint of fatigue, dry mouth, and recent weight gain, which are attributed to side effects of their antidepressant. Their antidepressant works by blocking presynaptic alpha-2 receptors and postsynaptic 5-HT2/3 receptors. What drug are they taking?
mirtazapine:
- blocks presynaptic alpha-2 receptors (decrease in neg. feedback for NE release)
- blocks postsynaptic 5-HT2 + 5-HT3 receptors (increases 5-HT1 receptor activity bc the other 2 are blocked)
also anti-histamine - causes sedation, dry mouth, increased appetite, weight gain
name 3 serotonin modulators which have minimal effect on NE or dopamine
- trazadone - tx insomnia
- vilazodone
- vortioxetine
what is the MOA and clinical use of trazadone?
weak serotonin reuptake inhibitor (5-HT2A and 5-HT2C)
5-HT antagonist at low doses, agonist at high doses
treats insomnia (sedating)
serotonin modulator that treats insomnia
trazadone: weak serotonin reuptake inhibitor (5-HT2A and 5-HT2C)
antagonist at low doses; agonist at high doses
