3 - Neuropsychoparmacology 1 Flashcards
Where are norepi, serotonin, dopamine, and acetylcholine localized in the brain? Where do they send axons?
Norepi: locus coeruleus
Serotonin: Raphe nuclei
-Both NE and 5HT send axons down the spinal cord to modulate pain pathways
Dopamine: ventral tegmental area and substantia nigra
Ach: POMC, nucleus basalis, septal nuclei
What are dopaminergic pathways in the brain responsible for? What are the pathways?
Beneficial and adverse effects of many antipsychotic drugs.
- Midbrain mesocortical and mesolimbic pathways - schizophrenia
- Nigrostriatal pathway - degen in parkinsons
- Hypothalamus to anterior pituitary - regulates prolactin release
Where is GABA localized?
Substantia nigra, globus pallidus, hippocampus, limbic structures (amygdala), hypothalamus, and spinal cord.
What percentage of the population has a mood disorder? Of those people, what diagnosis is most common?
40% of the population.
Most of those (about 15%) are major depressive disorder.
What are the criteria for major depressive disorder?
Must have 5 or more for 2 weeks(one of these symptoms must be depressed mood or loss of pleasure:
Depressed mood, diminished interest or pleasure, weight change, insomnia/hypersomnia, fatigue, feeling worthless, inappropriate guilt, agitation, difficulty concentrating, suicidal ideation.
What occurs at the norepinephrine synapse?
Tyr brought in and made into DOPA, then dopamine (DA), then brought into vescicles where it’s turned into NE.
NE is released into the synapse and can bind to alpha and beta receptors.
NE left in synapse goes through reuptake and can be reused or metabolized by monoamine oxidase (MAO).
What is the effect of tricyclic antidepressants on noradrenergic transmission? What occurs after taking there for awhile?
Blocks reuptake of NE, causing more transmitter to be in the synapse.
After 2-3 weeks, you see more norepi in the synapse and less receptors (due to down-regulation).
What other drug types cause down regulation of receptors with chronic use?
TCAs
SSRIs
Mirtazapine
MAOIs
What is the restated monoamine hypothesis?
Depression is due to biogenic amine receptor or transmission imbalance.
The various drugs that we are discussing act to change the imbalance and restore a more normal affect.
What drugs are used to treat depressive disorders?
SSRIs SNRIs Atypical drugs TCAs MAOIs
What are examples of 5-HT uptake inhibitors (SSRIs)? How do their effects differ from TCAs? What are their side effects?
Fluoxetine and sertraline.
Similar in efficacy and time course to TCAs. Less acute toxicity than TCAs and MAOIs.
Side effects: nausea, insomnia, and sexual dysfunction. Serotonin reaction can occur if given with MAOIs.
FDA requires warnings about associated of SSRIs and SNRIs with _____ ______ ______. What did clinical studies show antidepressants can cause?
Neuroleptic malignant syndrome.
Increased risk of suicidal thinking and behavior in children and adolescents with depression and other psychiatric disorders.
What are symptoms of SSRI withdrawl? When do these symptoms begin?
Dizziness, light-headedness, vertigo, shock-like sensations, paresthesia, anxiety, diarrhea, fatigue, gait instability, headache, insomnia, irritability, nausea/vomitting, tremor, visual disturbances.
Symptoms begin within 1-7 days after stopping SSRI.
What are the approved uses of SSRIs?
Major depression OCD Panic disorder Social anxiety disorder PTSD Generalized anxiety disorder Premenstrual dysphoric disorder Hot flashes from menopause
What was the first SSRI on the market with a long half-life active metabolite that lasts 7 days or more and has effects on drug metabolism? What is it approved to treat and how is it given?
Fluoxetine.
Sustained release product for Premenstrual dysphoric disorder (PDD).
What SSRI has a similar action to fluoxetine with less effects on drug metabolism and a shorter half life? What is it used to treat?
Sertraline.
OCD, PTSD, and panic attacks.
What are the effects of SNRAs? What are their side effects?
Blcok both 5-HT and NE reuptake.
Side effect profile is more like SSRI-like than TCA-like.
What is a SNRI with a 12-18 hour half life? What is it used for and what considerations need to be made?
Duloxetine.
Also approved for neuropathic pain syndromes, fibromyalgia, back pain, and osteoarthritis.
Use with caution in pts with liver disease. Can cause withdrawl symptoms.
How are SNRIs and TCAs similar? How do they differ?
Both block serotonin and norepi reuptake, treat neuropathic pain and depressive disorders.
TCAs are “dirty” drugs and binds lots of receptors to cause other effects such as H1 receptors (sedation), muscarinic receptors (burred vision, retention, constipation, glaucoma), and alpha adrenergic receptors (hypotension, dizziness, and reflex tachy).
What are Atypical antidepressants?
Drugs without typical tricyclic structure or SSRI or SNRI action. May or may not block catecholamine uptake.
What atypical antidepressant is also approved for nicotine withdrawl and seasonal affective disorder? What is its action? What are benefits?
Bupropion: weakly blocks NE and dopamine uptake.
No weight gain or sexual dysfunction.
What atypical antidepressant increases apetite and is often used for AIDs patients? How does this drug work?
Mirtazapine.
Blocks presynaptic alpha2 receptors in the brain.
What is the function of tricyclic antidepressents?
Block NE and 5-HT reuptake.
Now used secondarily to SSRIs and other new compounds,
Long plasma half-life: 8-100 hrs.
What are some pharmacological properties and effects of TCAs?
Elevation in mood after 2-3 wks.
Decreases REM and increases stage 4 sleep.
Prominent anticholinergic effects: can cause cardiac abnormalities like palpitations, tachy, and arrythmias.
Sedation.
Overdose/acute toxicity: hyper or hypotension, seizures, coma, and cardiac conduction effects.