Tavalin - Antidepressants Flashcards
What are the TCA’s?
- Amitriptyline
- Nortriptyline
- Protriptyline
- Imipramine
- Clomipramine
- Desipramine
- Trimipramine
- Doxepin
What are the SSRI’s?
- Citalopram
- Escitalopram
- Fluoxetine
- Paroxetine
- Sertraline
- Fluvoxamine
What are the atypical antidepressants?
- Venlafaxine
- Duloxetine
- Bupropion
- Mirtazapine
- Maprotiline
- Vortioxetine
- Amoxapine generic
- Trazodone
- Nefazodone generic
- Vilazodone
What are the MAOI’s?
- Tranylcypromine
- Isocarboxazid
- Phenelzine
What are the mood stabilizers?
- Lithium
- Valproate
- Carbamazepine
What is depression?
- Heterogeneous affective disorder that manifests itself in emotional, cognitive, behavioral, and somatic regulation
- Interfere with ability to work, study, sleep, eat, and enjoy once pleasurable activities
- Disabling episodes may occur only once, but more commonly occur several times in a lifetime
- Lifetime prevalence of 17%
- 15% of prescriptions in US are for depression
What are the symptoms of depression?
- CORE SYNDROME + “VITAL SIGNS”
- NOTE: symptoms may occur to varying severity
What are the symptoms of the depressive core syndrome?
- Persistent sad, anxious, tense, or empty mood
- Feelings of hopelessness, pessimism, guilt, worthlessness, and helplessness
- Persistent physical symptoms that do not respond to tx, like headaches, digestive disorders, and chronic pain
What are the “vital signs” of depression?
- Difficulty concentrating, remembering, making decisions
- Loss of interest or pleasure in hobbies or activities that were once enjoyed, incl. sex
- DEC energy, fatigue, being “slowed down”
- Insomnia, early morning awakening, or oversleeping
- Appetite and/or weight loss or overeating and weight gain
- Thoughts of death or suicide; suicide attempts
- Restlessness, irritability
- NOTE: reflective of somatic disturbances
What are the 3 classifications of depression?
- Reactive (secondary): about 60%
- Major depressive disorder (endogenous; unipolar): about 25%
- Bipolar disorder (manic depression): 15%
What are the features of reactive (secondary) depression?
- 60%
- Associated w/loss (adverse life events), physical illness, drugs (anti-HTN, alcohol, hormones), or other psychiatric disorders (senility)
- Consists of CORE depressive syndrome
- May remit spontaneously, or in response to drugs
What are the features of major depressive disorder (endogenous; unipolar)?
- 25%
- Typically recurrent; consists of core syndrome and vital symptoms
- Precipitating life event not adequate for the severity, and may be unresponsive to life events (autonomous)
- Any age, but peak onset 20-40 yrs
- More common in F; INC risk +/- 3 months childbirth
- Family hx of depressive disorder is common, i.e., genetic
- Responsive to anti-depressant drugs and ECT
What are the features of bipolar disorder (manic depression)?
- 15%
- Characterized by alternating episodes of depression and mania
- Misdiagnosed as endogenous depression if manic episodes missed
- Treated with mood stabilizers (and possibly antipsychotics), in addition to anti-depressants
What are the symptoms of mania?
- Abnormal or excessive elation
- Unusual irritability
- DEC need for sleep
- Grandiose notions
- INC talking
- Racing thoughts
- INC sexual desire
- Markedly INC energy
- Poor judgment
- Inappropriate social behavior
What is the biogenic amine hypothesis for depression? How are AD’s involved?
- Functional deficit of MA’s (esp. NE and 5-HT) thought to be involved in depression pathophys
- Example: Reserpine disrupts MA storage and causes symptoms of depression -> AD’s act to INC level of MA’s
- THERAPEUTIC LAG: NE and 5-HT INC immediately after AD admin, but takes weeks (2-8) to see clinical effects -> suggests adaptive changes underlie response
- Changes in β-receptor coupling, cAMP and serotonergic neurotransmission, SN alterations, and neurogenesis via brain-derived neurotropic factor -> acute effects appear to be required
What is therapeutic lag?
- NE and 5-HT INC immediately after AD admin, but takes weeks (2-8) to see clinical effects, suggesting adaptive changes underlie response
- Changes in β-receptor coupling, cAMP and serotonergic neurotransmission, SN alterations, and neurogenesis via brain-derived neurotropic factor -> acute effects appear to be required
What is the stress hormone hypothesis for depression?
- Stress hormones CRH and cortisol dysregulated
What is the most recent hypothesis for depression?
- Mistrafficking of 5HT1c receptors via p11
- p11 is an IC trafficking protein important for controlling responsiveness to AD agents
Should depressed people take NSAID’s?
- NSAIDs DEC cytokines, so they may be CONTRA in some forms of depression
Describe the presynaptic packaging and release of NE and 5-HT, and their targets.
- NE and 5-HT presynaptically synthesized from AA precursors L-tyrosine and L-tryptophan, respectively
- Packaged in vesicles by vesicular monoamine transporter
- Upon invasion of presynaptic AP to terminals, depolarization drives voltage-dependent Ca channels to open, and fusion of vesicles with presynaptic membrane —> opening of fusion pore and release of NT into synaptic cleft
- NE, 5-HT can activate post-synaptic receptors and initiate signaling cascades that modulate neuronal excitability and other cell function
- Can act presynaptically at auto- and hetero-receptors to suppress release
- NE receptors on 5-HT terminals, and vice versa: mechanism for them to cross-modulate each other
How is NE and 5-HT synaptic transmission terminated? What drugs affect this termination?
- Action terminated by action of presynaptic transporters called NET and SERT that recycle transmitter back to their respective presynaptic terminals, where they may be re-packaged, or degraded by monoamine oxidases (MAO’s)
- TCA’s and SNRI’s act to block reuptake and prolong residency of these transmitters in synaptic cleft
- SSRI’s act selectively to prolong serotonergic action (at SERT)
What is the basic action of the MAOI’s?
- MAOI’s prevent presynaptic degradation of NE and 5-HT, INC their availability for release
What is the BBW for the anti-depressants?
- Potential INC of suicidal thinking or attempts in kids and young adults (up to 24 years)
- Pts should be closely monitored, esp. during the initial weeks of tx
- NOTE: comprehensive review recommends that benefits outweigh risks for kids and adolescents with severe depression and anxiety disorders
What kinds of things do you need to monitor in a pt on anti-depressants?
- Worsening depression
- Suicidal thinking or behavior
- Any unusual changes in behavior, like sleepiness, agitation, or withdrawal from normal social situations
What is the role of the placebo effect in anti-depressant tx?
- Strong placebo effect associated with emotional disorders, incl. generalized anxiety disorder
Is St. John’s Wort clinically effective? What else do you need to worry about with pts on this med?
- Maybe
- Recent NIH study found that it was no more effective in treating major depressive disorder than placebo, and worse than an SSRI
- CYP450 inducer: 2000 FDA warning that SJW interferes with various meds, esp. for HIV, heart disease, seizures, some cancers, and organ transplant reduction
- NOTE: trials currently under way for mild-moderate depression (extract of hypericum perforatum)
Describe the pharmacogenomics of resistance to AD tx. Which drugs are most affected?
- Recent study shows many AD’s are substrates for ABCB1 (MDR1; P-gp) at the BBB, limiting the abilities of these drugs to accumulate in brain
- Single nucleotide (T vs. C) polymorphisms in MDR1 may dictate whether depression will remit in response to AD tx
- SUBSTRATES: Citalopram, Venlafaxine, Paroxetine, Amitriptyline
- NOT SUBSTRATES: Mirtazapine, Fluoxetine
- Pts who are C carriers (CC or CT) tend to have depression that does not remit in response to drugs that are substrates for MDR1, but equal remission rates to drugs that are not substrates -> C-allele dictates overall higher rate of MDR1 transport activity for those drugs that are substrates and a reduced accumulation of these drugs in the brain