Anti-Depressants Flashcards
According to the biogenic amine theory, depression is due to a deficiency of which two neurotransmitters in the brain?
- Serotonin (5-HT)
2. Norepinephrine (NE)
MAO-A inactivates which neurotransmitters?
5-HT; NE
MAO-B inactivates which neurotransmitters?
Dopamine (DA)
What is the MOA of MAOIs?
Inactivation of MAO –> increase levels of 5-HT, NE, DA in presynaptic neurons w/ subsequent leakage of neurotransmitter into synaptic cleft
Name 3 nonselective MAOIs
- Tranylcypromine
- Phenelzine
- Isocarboxazid
Selegiline is commonly used in the treatment of which disease?
Parkinson disease
MAO-A also inactivates which monoamine commonly found in certain cheeses (aged), alcoholic beverages, fish, chocolates, red wines, and processed meats?
Tyramine (inactivated by MAO in GI tract)
MAOIs are the drugs of choice for treating what type of depression?
Atypical depression
How long does it take to see antidepressant effects in patients who are started on an MAOI?
2~4 weeks
How long should a patient wait from the time of discontinuing an MAOI to the time of starting a new antidepressant medication?
At least 2 wks
What are the adverse effects of MAOIs?
Orthostatic hypotension; xerostomia; blurred vision; drowsiness; constipation; urinary retention
What life-threatening condition may develop when MAOIs and SSRIs are used concomitantly?
Serotonin syndrome
What characterizes serotonin syndrome?
Rigidity; diaphoresis; hyperthermia; seizures; autonomic instability; myoclonus
What life-threatening condition may develop when patients taking MAOIs ingest foods containing tyramine?
Hypertensive crisis
What characterizes hypertensive crisis?
HTN; HA; Tachycardia; N/V; stroke; arrhythmias
A serotonin-like syndrome may develop when MAOIs are used concomitantly with what common OTC medication used to suppress cough?
Dextromethorphan
A serotonin-like syndrome may develop when MAOIs are used concomitantly w/ which opioid analgesic?
Meperidine
What is the MOA of TCAs?
Inhibits reuptake of 5-HT & NE into presynaptic neurons –> increase neurotransmitter concentrations in synaptic cleft
What other types of neurotransmitter and hormonal receptors, other than 5-HT and NE, are inhibited by TCAs?
Muscarinic; alpha-adrenergic; histaminergic
How long does it take to see antidepressant effects in patients who are started on a TCA?
4~6 wks
Give examples of TCAs
Amitriptyline; imipramine; clomipramine; nortriptyline; protriptyline; desipramine; doxepin
What is the name of the active metabolite of amitriptyline that selectively inhibits NE reuptake?
Nortriptyline
What is the name of the active metabolite of imipramine that selectively inhibits NE reuptake?
Desipramine
Which TCA is also used for the treatment of certain types of neuropathic pain and for the prevention of migraine HAs?
Amitryptyline
Which TCA is commonly used to treat OCD?
Clomipramine
Which TCA is also used to treat pediatric nocturnal enuresis (aka uncontrolled pissing)
Imipramine
Why is imipramin used for childhood enuresis?
Increases contraction of internal sphincter of bladder; decreases stage 3 & 4 of sleep
What are the adverse effects of the TCAs?
Xerostomia; blurred vision; urinary retention; arrhythmias; seizures (lowers seizure threshold); orthostatic hypotention w/ reflex tachycardia; sedation; serotonin syndrome (when combined w/ MAOIs or SSRIs); coma
What are the “3 C’s” of TCA toxicity/
Coma, Convulsions, Cardiotoxicity
Compare TCA toxicity to SSRI toxicity
SSRI toxicity: much lower than TCAs. Mortality only reported when combined w/ alcohol.
TCAs toxicity: can lead to death @ much lower concentrations compared to SSRIs
What is the treatment for TCA OD?
Activated charcoal to absorb the drub in GI tract; sodium bicarb to correct acidosis & cardiac arrhythmias; phenytoin; Mg
What is the MOA of trazodone and nefazodone?
Inhibits reuptake of 5-HT into presynaptic neurons –> increase neurotransmitter concentration in synaptic cleft
What AE is unique to trazodone?
Priapism (aka EPIC HARD-ON, BONER-for-DAYS)
What is the MOA of bupropion?
Weak inhibitor of DA, 5-HT, NE reuptake
Bupropion is also used in what settings (other than depression)?
Smoking cessation; OCD
Does bupropion cause sexual dysfx?
No. Making it useful alternative in patients w/ sexual dysfx w/ other antidepressants such as SSRIs
Is bupropion safe to use in patients w/ epilepsy?
No, b/c it lowers seizure threshold
What is the MOA of mirtazapine?
Weight gain via appetite stimulation (may be beneficial in depressed patients who b/cm anorexic)
Name an alpha-antagonist that is used in treatment of ED?
Yohimbine
What is the MOA of venlafaxine?
Potent inhibitor of 5-HT and NE reuptake; weak inhibitor of DA reuptake
What is the major side effect of venlafaxine?
HTN
What is the MOA of duloxetine?
Selective serotonin and NE reuptake inhibitor (SSNRI)
Give examples of SSNRIs
Fluoxetine; paroxetine; fluvoxamine; sertraline; citalopram; escitalopram
What is the prototype of the SSRI drug class?
Fluoxetine
What is the longest-acting SSRI?
Fluoxetine
Fluoxetine is also used in what settings (other than depression)?
Premenstrual dysphoric disorder (PMDD); bulimia nervosa; OCD; panic disorder; selective mutism
What kind of drug interactions may SSRIs produce?
Inhibition of CYP P450
Do SSRIs cause sexual dysfx?
Yes. They can cause anorgasmia (NOOOOOO! #sadlife)
Do SSRIs cause cardiac arrhythmias?
No, they do not. In contrast to TCAs
What are the AE of SSRIs?
Sexual dysfx; agitation; anxiety; seizures (w/ OD); N/V; diarrhea; sedation
Which SSRI is also FDA approved for social anxiety disorder, generalized anxiety disorder, and PTSD?
Paroxetine
Which SSRIs cause the lease amount of drug-drug interactions?
Citalopram; escitalopram; sertraline
