antidepressants Flashcards
Amitriptyline (Elavil®)
- tertiary amine
- Tricyclic Antidepressants (TCAs)
Imipramine (Tofranil®)
- tertiary amine
- Tricyclic Antidepressants (TCAs)
Nortriptyline (Pamelor®)
- secondary amine
- Tricyclic Antidepressants (TCAs)
Desipramine (Norpramin®)
- secondary amine
- Tricyclic Antidepressants (TCAs)
Phenelzine (Nardil®)
Monoamine Oxidase Inhibitors (MAOIs)
Selegiline (Deprenyl®)
Monoamine Oxidase Inhibitors (MAOIs)
Fluoxetine (Prozac®)
Selective Serotonin Reuptake Inhibitors (SSRIs)
Paroxetine (Paxil®
Selective Serotonin Reuptake Inhibitors (SSRIs)
Sertraline (Zoloft®)
Selective Serotonin Reuptake Inhibitors (SSRIs)
Citalopram (Celexa®
Selective Serotonin Reuptake Inhibitors (SSRIs)
Venlafaxine (Effexor®)
5-HT and NE Reuptake Inhibitors (SNRIs)
Duloxetine (Cymbalta®)
5-HT and NE Reuptake Inhibitors (SNRIs)
which neurotransmitter is responsible for reward, motivation, euphoria, and movement
dopamine
which neurotransmitter is responsible for reward, arousal, alertness, decisions, and flight or fright
NE/noradrenaline
which neurotransmitter is responsible for mood, emotion, memory, sleep, and cognition
serotonin (5-HT)
what is the Monoamine Hypothesis of depression
- amine neurotransmitters are DA, NE, and serotonin
- depression results from abnormal or decressed neurotransmission of dopamine, norepinephrine and serotonin
evidence for the Monoamine Hypothesis is that patients treated with Reserpine which depletes neurons of noradrenaline (NE) and serotonin (5-HT) developed what
- depression
* This suggested that depression had something to do with a deficit of NE and 5-HT.
the antidepressant effect takes 2-3 weeks due to
neural plasticity
differentiate between short term effects and long term effects of uptake inhibitors
- Normal - amine levels in synapse are modulated by reuptake and presynaptic inhibition
- short term Uptake inhibitors - amine levels in synapse are increased BUT so does feedback inhibition so synaptic amine levels are balanced
- Long-term - Antidepressants downregulate auto-receptors (which control firing rate of neuron by negative feedback); increasing firing rate of amine neurons
MOA of tricyclic antidepressants
- inhibit re-uptake of NE and serotonin
- also block a-adrenergic, histamine and muscarinic receptors
list uses of tricyclic antidepressants
- depression: not first line
- chronic pain (TMJ)
List the tertiary amines TCA
- amitriptyline (Elavil®)
- imipramine (Tofranil®)
MOA of tertiary amines. adverse effects?
- primarily inhibit serotonin re-uptake
- produce more seizures and are more sedating than secondary amines
List the secondary amines TCA
- nortriptyline (Pamelor®)
- desipramine (Norpramin®)
MOA of secondary amine TCA
primarily block NE re-uptake
List the 4 dopamine pathways
- nigrostriatal
- mesolimbic
- mesocortical
- tubero-infundibular
TCAs are metabolized by
CYP2D6: thus drug interactions are very common
List the side effects of TCA
- weight gain
- histamine receptor blockade -> sedation
- cholinergic blockade -> blurred vision, tachycardia, constipation, dry mouth, impaired memory
- a1 receptor blockade -> postural hypotension, reflex tachycardia
- analgesia
- SIADH -> hyponatremia
- sexual dysfunction
- decrease in sz threshold
can TCAs be used in pregnant patients
yes
TCA toxicity can lead to what cardiac abnormality
- Torsades de pointes
- antidote: magnesium
Monoamine oxidase inhibitors and TCAs together can result in what condition? what are the signs of this condition?
-
serotonin syndrome
- severe CNS toxicity
- fever
- convulsions
- coma
- severe CNS toxicity
List the Selective Serotonin Reuptake Inhibitors (SSRIs)
- Fluoxetine (Prozac®)
- Paroxetine (Paxil®)
- Sertraline (Zoloft®)
- Citalopram (Celexa®)
Escitalopram (Lexapro)
SSRI
obsessive compulsive disorder and social anxiety are usually treated with what SSRI
- Paroxetine (Paxil)
of the SSRIs, which is the most likely to inhibit CYP450 enzymes? specially which enzymes?
- Fluoxetine
SSRI drug of choice in an elderly patient? why?
- sertraline (zoloft)
- due to shorter half life of 26 hours
- least likely to interact with other drugs
DOC for depression
-
SSRI
- specifically Citalopram
MOA of SSRIs
selectively inhibits serotonin reuptake
list the side effects of SSRIs
- mild side effects
- sexual dysfunction
fluoxetine has what drug interaction with codeine
- it inhibits the conversion of codeine to morphine
SSRIs + MAOI will cause
serotonin syndrome
SSRI + St johns wart or amphetamines will cause
serotonin syndrome
SSRI/MAOI/ or TCA + tramadol can cause
- tramadol is a mu agonist
- inhibits NE/serotonin uptake and can cause seizures and serotonin syndrome
MOA of serotonin-norepinephrine reuptake inhibitors
- inhibit reuptake of NE and 5-HT reuptake
side effect of venlafaxine
may increase blood pressure
side effects of duloxetine
- hepatotoxicity
- bilateral acute angle-closure glaucoma
MOA of Monoamine oxidase inhibitors
irreversibly inhibit MAOs which metabolize NE, DA, and serotonin -> get increased amounts of these
MOA of MAO-A
- metabolize NE, DA, and serotonin in both the CNS and periphery (GI tract)
MOA of MAO-B
- selectively metabolizes DA in the CNS but not the GI tract
MOA of Phenelzine
- inhibits both MAO-A and MAO-B
- increases NE, serotonin, and DA
- drug of last choice
MOA of Selegiline
- selectively inhibits MAO-B
- increases DA
- fewer side effects
side effects of Phenelzine
- hypertensive crisis
with what medication should you avoid use with tyramine? why
- MAOI: phenelzine
- foods with tyramine: red wine, beer, aged cheese
- MAO-A is inhibited in GI tract, tyramine causes release of amines and with limited metabolism by MAO-A can get severe hypertension
MAOI + SSRIs or TCAs can lead to
serotonin syndrome
MAOI + OTC cold and cough medication containing sympathomimetic amines (ephedrine or amphetamines) can lead to
severe hypertension
MAOIs affect on 2D6
inhibit 2D6
MOA of Buproprion (wellbutrin)
- inhibits DA reuptake
when is Buproprion (wellbutrin) used
- ADHD
- alcoholism (reduces craving)
side effects of Buproprion (wellbutrin)
- seizures: CI in patients with h/o sz
- anxiety, insomnia, tremor
- tachycardia
- sexual dysfunction rare
MOA of Mirtazapine
- blocks presynaptic alpha 2 receptors which inhibits release of NE and 5-HT
- increases relase of NE and 5-HT
side effects of Mirtazapine
- blocks histamine receptors -> drowsiness
good drug to use in patient who is depressed with insomnia or anxiety
Mirtazapine
MOA of Atomoxetine
- selective inhibitor of NE reuptake
use of Atomoxetine
- ADHD
- does not cause euphoria so good for addicts
MOA and use of Trazodone
- 5-HT receptor antagonist
- sedating -> more often used as sleep aid and pain management
St. johns wort may be effective in mild depression but it should not be combined with what
- other antidepressants
- will cause serotonin syndrome
Side effect of Trazodone
Liver failure