Antidepressant drugs Flashcards
name 7 antidepressant drug categories?
- MAO inhibitors
- TCA’s
- Serotonin selective reuptake inhibitors
- Dual serotonin & norepinephrine reuptake inhibitors
- 5-HT2 antagonists/reuptake inhibitors
- NEpi & dopamine reuptake inhibitors
- Antagonists at alpha2, 5-HT2 & 5-HT3 receptors
what are some MAO inhibitors?
- isocarboxazid
- phenelzine
- tranylcypromine
- selegline
- isocarboxazid
- phenelzine
- tranylcypromine
- selegline
MOA?
inhibit MAO-A
what are the two types of MAO’s?
MAO-A and MAO-B: metabolize dopamine and tyramine
MAO-A: metabolizes NEpi and serotonin
What are the two hydrazine deveratives of MAO?
- phenelzine
2. isocarboxazid
what are the two non-hydrazines derivatives of MAO?
- tranycypromine
2. selegiline
- isocarboxazid
- phenelzine
- tranylcypromine
MOA?
bind irreversibly and nonselectively to MAO-A and MAO-B.
which MAO is approved to treat Parkinson’s?
selegiline: MAO-B inhibitor.
high dose can inhibit MAO-A
avail as transdermal
- isocarboxazid
- phenelzine
- tranylcypromine
- selegline
Uses?
rarely used d/t toxicity and food/drug interactions
tx: depression unresponsive to other antidepressants
- isocarboxazid
- phenelzine
- tranylcypromine
- selegline
A.E?
- drowsiness
- insomnia
- nausea
- orthostatic hypotension
- weight gain
- muscle pain
- sexual dysfunction
- isocarboxazid
- phenelzine
- tranylcypromine
- selegline
two classes of Drug interactions?
- serotonin syndrome
2. cheese rxn.
What is serotonin syndrome?
combination of MAOI c a serotonergic agent.
Life-threatening
- hyperthermia
- muscle rigidity
- myoclonus
overstimulation of 5-HT1A and 5-HT2 receptors
What is the cheese rxn?
tyramine is contained in certain foods - cheese, chicken liver, soy, pickled fish and red wines.
tyramine inactivated by MAO in the gut. Pts on MAOI cannot degrade tyramine -> release of catecholamines 1. tachycardia 2. htn 3. arrhythmias 4. seizures 5. stroke
what are other MAOI drug interactions?
- sympathomimetic drugs
2. OTC cold preps contain pseudoephedrine and phenylpropanolamine.
What are two drugs help c cheese rxn?
- phentolamine
- prazosin
manage htn
Which MAOI’s is better tolerated and safer and unlikely to cause tyramine-induced htn?
selegiline transdermal patch
what is MAOI discontinuation syndrome?
abrupt d/c of MAOI’s
- worsening of depressive sx’s
- confusion
- disorientation
- psychosis
- anxiety
What are some TCAs?
- amitriptyline
- Clomipramine
- desipramine
- imipramine
- nortriptyline
- amitriptyline
- Clomipramine
- desipramine
- imipramine
- nortriptyline
mOA?
block SERT and NET -> increased monoamine conc in the cleft.
clomipramine = more selective for SERT
Desipramine and nortriptyline = more selective for NET
- amitriptyline
- Clomipramine
- desipramine
- imipramine
- nortriptyline
A.E?
block musc receptors:
- blurred vision, xerostomia, urinary retention, constipation and aggravation of narrow-angle glaucoma
alpha1-adrenoceptors:
- orthostatic hypotension, reflex tachycardia
H1 blockage:
- sedation and weight gain
Sexual effects:
- more in clomipramine
block cardiac fast Na channels -> arrythmias (COD)
- amitriptyline
- Clomipramine
- desipramine
- imipramine
- nortriptyline
Precautions?
narrow therapeutic index
pts c suicidal thoughts should be given only limited quantities and monitor closely
- amitriptyline
- Clomipramine
- desipramine
- imipramine
- nortriptyline
Overdose?
induce lethal arrythmias
Na bicarbonate = use to reverse conduction block.
- amitriptyline
- Clomipramine
- desipramine
- imipramine
- nortriptyline
discontinuation syndrome?
- flulike sx’s
- myalgia
- excessive sweating
- HA
- nausea
- insomnia
What are amoxapine and Maprotiline and their MOA?
TCAs
potent NET inhibitors and less potent SERT inhibitors.
Both posses anticholinergic properties.
Amoxapine is moderate antagonist of D2 receptors: antipsychotic properties.
What are some Selective Serotonin-reuptake inhibitors (SSRI)?
- citalopram
- escitalopram
- fluoxetine
- fluvoxamine
- paroxetine
- sertraline
- citalopram
- escitalopram
- fluoxetine
- fluvoxamine
- paroxetine
- sertraline
MOA?
inhibit serotonin uptake
- citalopram
- escitalopram
- fluoxetine
- fluvoxamine
- paroxetine
- sertraline
uses?
- depression (DOC)
- OCD
- PD
- GAD
- PTSD
- SAD
- PMDD
- bulimia
- citalopram
- escitalopram
- fluoxetine
- fluvoxamine
- paroxetine
- sertraline
A.E?
- increased serotonergic activity in gut = nausea, GI upset, diarrhea
- increased serotonergic tone in CNS = diminished sex function/interest.
- weight gain (esp c paroxetine)
- citalopram
- escitalopram
- fluoxetine
- fluvoxamine
- paroxetine
- sertraline
Drug interactions?
- fluoxetine and paroxetine inhibit CYP2D6
- Fluvoxamine inhibits CYP1A2, CYP2C9 and CYPT3A4
- citalopram, escitalopram and sertraline - low potential for interactions
- serotonin syndrome if used c MAOI or another serotonergic rx.
- citalopram
- escitalopram
- fluoxetine
- fluvoxamine
- paroxetine
- sertraline
Overdoses?
fatality is low but can cause seizures.
- citalopram
- escitalopram
- fluoxetine
- fluvoxamine
- paroxetine
- sertraline
D/c syndrome?
- nervousness
- anxiety
- irritability
- tearfulness
- electric shock sensations
- dizziness
- insomnia
- confusion
- confusion
- nausea
Which SSRIs is most severe in d/c syndrome and which is least?
severe: paroxetine d/t short half life
least: fluoxetine d/t longer half life
What are some Serotonin/NEpi reuptake inhibitors (SNRI)?
- venlafaxine
2. duloxetine
- venlafaxine
- duloxetine
MOA?
block reuptake of serotonin and NEpi.
venlafaxine:
potent inhibitor of 5HT uptake
high doses: inhibits NEpi uptake
inhibit reuptake of dopamine weakly.
duloxetine:
inhibits serotonin and NEpi reuptake at all doses
- venlafaxine
- duloxetine
drug interactions?
few CYP450 interactions
- venlafaxine
- duloxetine
d/c syndrome?
vanlafaxine most d/t short half-life
what is a NEpi & dopamine reuptake inhibitors (NDRI)?
bupropion
bupropion
MOA?
inhibits NEpi and dopamine uptake
increases NEpi and dopamine release.
bupropion
overdose?
seizures
what are two 5HT2 antagonists/reuptake inhibitors (SARI)?
- Nefazodone
2. Trazodone
- Nefazodone
- Trazodone
MOA?
when 5HT reuptake is blocked by SSRIs, all 5HT recpetors are stimulated.
stimulation of 5HT1A receptors in raphe may help depression.
stimulation of 5HT2 receptors in forebrain = agitation/anxiety; spinal cord = sex dysfunction.
SARIs combine 5HT reuptake blockage c 5HT2 antagonism -> decrease undesired actions of stimulation of 5HT2 recptors.
- Nefazodone
- Trazodone
A.E?
Nefazodone:
hepatotoxicity (no longer prescribed)
Trazodone:
- xtreme sedation
- hypnotic (main use)
- priapism (rare)
What is a Noradrenergic & Specific serotonergic antidepressants (NASSA)?
Mirtazapine
Mirtazapine
MOA?
antagonist of central presynaptic alpha2 receptors -> enhance release of NEpi and 5HT
antagonist at 5HT2 and 5HT3 recptors
H1 antagonist: sedation and weight gain
useful in insomnia or agitation
What are some adjunctive tx of major depressive disorder?
- quetiapine
- aripiprazole
- olanzapine
What are some clinical indications of antidepressants?
- depression (SSRI)
- anxiety disorders (SSRI first choice, bupropion least effective)
- chronic pain (TCAs and SNRI = neuropathic, SSRIs are not effective)
- eating disorders (help bulimia but not anorexia)
- Premenstrual dysphoric disorder (SSRIs)
- smoking cessation (bupropion)
What are some antidepressants warnings/precautions?
Major Depressive Episode may be initial presentation of bipolar.
- tx c antidepressant alone = precipitate mania
- must screen for evidence of bipolar disorder.
What are some drugs for bipolar disorder?
- lithium
- Valproate
- Carbamazepine
Lithium
uses?
tx of manic-depressive pts and manic episodes
Lithium
MOA?
inositol depletion theory:
G protein (Gq) activate PLC -> yield DAG and IP3
IP3 signal is terminated by conversion to IP2
IP2 is converted to IP1 by inositiol polyphosphatase
IP1 is converted to inositol by inositol monophosphatase
Lithium inhibits inositol polyphosphatase and monophosphatase = block regenration of inositol -> blcok signaling cascade in brain
Lithium inhibits central adrenergic, musc, and serotonergic neurotransmission.
ONLY affect neurons c active receptors!!
Lithium
acute A.E?
narrow therapeutic window
- vomiting
- profuse diarrhea
- coarse tremor
- ataxia
- coma
- convulsions
- death (if plasma conc 3-5mM)
Lithium
A.E?
- tremor, sedation, ataxia, aphasia = alleviate by propranolol or atenolol.
- seizures
- weight gain
- hypothyroidism
- nephrogenic diabetes insipidus
- edema
- dermatitis
- alopecia
- leukocytosis
Lithium
in pregnancy?
increase incidence of congenital cardiac anomalies
Cat D
contraindicated in nursing mothers.
Lithium
Monitoring?
- serum lithium conc
- thyroid function
- renal function
Lithium
Drug interactions?
- thiazide diuretics
- NSAIDs
- ACE inhibitors
- ARBs
What are alternatives to lithium?
- valproate
2. carbamazepine
- valproate
- carbamazepine
Monitoring?
valproate: cbc and liver
carbamazepine: cbc
what are some atypical antipsychotics can be used as lithium alternatives?
- olanzapine
- aripiprazole
- quetiapine
- risperidone
- ziprasidone
what is an antiepileptic can be used as lithium alternative?
Lamotrigine
What is the monoamine hypothesis?
deplete in monoamine = depression