Halter chapter 3 Psychobiology & Psychopharmacology

Structure and Function of the Brain

- maintenance of homeostasis

- regulation of the autonomic nervous system & hormones

- control of biological drives & behavior

- regulates sleep/wake cycle/circadian rhythms

- control conscious mental activity

- store memories

- social skills

the homeostatic linkage between the brain and the internal organs explains what?

why mental disturbances like anxiety alter internal function

hypothalamic-pituitary-adrenal (HPA) axis

influences most psychiatric disorders

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

what is the major target of most drugs used to treat psychiatric disorders?

the interaction between the neurotransmitter and the receptor

the limbic system plays a crucial role in what?

emotional status & psychological function by using norepinephrine, serotonin, and dopamine

Serotonin

"feel good" neurotransmitter

- involved in sleep regulation, mood, Appetit

-low levels are linked to depression, anxiety and some mental disorders

-associated with autism (high levels)

- exercise and light levels can have positive effects on serotonin

Dopamine

- motor activity and thinking

- pleasure, satisfaction, motivation

- Increase= delusions and hallucinations

- decrease= muscle rigidity and Parkinsons

- blocking increase prolactiin

Hypothalamus

- controls basic drives

- linking thought, emotion, and the functioning of internal organs

- processing sensory informatoin

- regulating sleep cycle and wakefulless

Brainstem

essential to the survival of all by controlling heart rate, breathing, digestion, and sleeping

cerebellum

regulates voluntary motor movements and balance of equilibrium

Cerebrum

very busy

- mental activities

- a conscious sense of being

- emotional status

- memory

- language and communication

- movement of skeletal muscles

frontal lobe

A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement

parietal lobe

A region of the cerebral cortex whose functions include processing information about touch.

occiptal lobe

vision

temporal lobe

A region of the cerebral cortex responsible for hearing and language.

anxiety disorders can be related to abnormalities in the ?

amygdala

Disturbances of Mental Function

Genetics & Neurotransmitters

External things such as infection, trauma, drugs, and hormones

Pharmacodynamics

what the drug does to the body and how they do it

Pharmacokinetics

movement of drug throughout the body

basic processes of Pharmacokinetics

ADME

absorption, distribution, metabolism, excretion

what metabolizes most drugs?

the liver

Antagonist

block the neurotransmitter

Agonist

mimic neurotransmitter

what is the major inhibitory (calming) neurotransmitter in the CNS?

GABA

what are the most commonly used antianxiety agents?

benzodiazepine

How do benzodiazepines work?

by promoting the activity of GABA

what are the 5 FDA-approved drugs for the treatment of insomnia with hypnotic effects?

Dalmane, restoril, halcion, Prosam, doral

Xanax & Ativan reduce what without being sleep producing when used at less therapeutic doses

anxiety

when used with other CNS depressants (alcohol, opiates), what do benzodiazepines do?

inhibitory actions of benzodiazepines can lead to life-threatening CNS depression

why must you caution a patient taking benzodiazepine about engaging in activities such as working in construction or driving a car?

because any drug that inhibits electrical activity in the brain can interfere with motor ability, attention, and judgment

Short-acting sedative-hypnotic sleep agents are?

Zolpidem (Ambien)

Zaleplon (Sonata)

Eszopiclone (Lunesta)

Short-acting sedative-hypnotic sleep agents have what?

sedative effects without the antianxiety, anticonvulsant, or muscle relaxant effects of benzodiazepines

why is it important to inform patients about taking nonbensozdiapines?

because of the quick onset of action and to take them when they are ready to sleep

how are the Z hypnotics categorized?

as schedule IV similar to Benzodiazepines

Eszopiclone (Lunesta)

longest duration of action (7-8 hours)

unpleasant bitter taste upon wakening

Melatonin

naturally occurring hormone that is only secreted at night

can cause dizziness and headache

doxepin

- low dose formulation for old tricyclic antidepressant

- indicated for the treatment of insomnia characterized by difficulty in maintaining sleep

- severy urinary retention should avoid along with other CNS depressant

suvorexant

promote normal wakefulness

selectivity blocks the binding of orexin to suppress wakefulness

Buspirone

reduces anxiety without the strong sedative-hypnotic properties

not a CNS depressant

Selective Serotonin Reuptake Inhibitors (SSRIs)

block reuptake of only serotonin

what are the Selective Serotonin Reuptake Inhibitors (SSRIs)

prozac, zoloft, paxil, celexa, lexapro, luvox

Norepinephrine & serotonin specific antidepressants

Drugs: remeron

Side effects: sedation, appetite stimulation, weight gain

How it works: increases norepinephrine and serotonin transmission by antagonizing presynaptic alpha 2 autoreceptors

Norepinephrine & dopamine reuptake inhibitor

drugs used to treat depression; inhibit the reuptake of both norepinephrine and dopamine; contradicted in patients with seizure disorder, bulimia or anorexia

Serotonin Antagonist/Reuptake Inhibitors (SARIs)

works by blocking serotonin receptors and weakly inhibiting the reuptake of norepinephrine and serotonin

Drugs:

Nefazodone (sedation, headache, fatigue, dry mouth, nausea, constipation, dizziness)

Trazodone (sedation, dizziness, orthostatic hypotension)

Rexulti (akathisia, weight gain)

Serotonin Modulator and Stimulator

drugs: trintellix

How they work: inhibiting serotonin reuptake while antagonizing other serotonin receptors

Side effects: constipation, nausea, vomiting

Serotonin Norepinephrine Reuptake Inhibitors (SNRIs)

increase both serotonin and norepinephrine

Pristiq (desvenlafaxine)

SNRI

primary active metabolite of venlafaxine

Venlafaxine (Effexor)

SNRI

serotonergic agent at lower doses

promotes norepinephrine reuptake at higher doses

Serotonin Partial Agonist/Reuptake Inhibitor (SPARI)

enhances the release of serotonin by inhibiting the serotonin transporter and by stimulating serotonin receptors through partial agonism

drug: Viibryd

reactions: diarrhea, nausea, insomnia, vomitting

tricyclic antidepressants

block reuptake of serotonin and norepinephrine

Monoamine Oxidase Inhibitors (MAOIs)

antidepressant medications that increase the amount of monoamine neurotransmitter in synapses

patients taking MAO must be given what?

a list of foods and drugs to avoid because of the dangers that result from inhibition of hepatic and intestinal MAO

Norepinephrine

Attention, alertness, assist with mood

Elevates BP and BS

Flight or fight

Increase causes anxiety, mania, and schizophrenia

Decrease causes ADHD and depression

GABA

Control muscle and vision

Calming firing nerves in CNS

Increase= day time sleepiness

Decrease= seizures, anxiety, moods disorder

Acetylcholine

Controls memory, learning, thoughts, and muscle control

Increase=sever muscle contraction

Decrease=alzihmers, memory deficits

Endorphins

Range over 20 in brain

Released during exercise, excitement, pain, sexual activity, euphoria

Pain regulation

Increase= block pain signals

Decrease= lead to pain

What does the brain look like?

Structured imaging: CT scans and MRI

Functional imaging: PET scans

Types of psychotherapeutic drugs

anxiolytic, mood-stabilizing, antidepressant, antipsychotic

Serotonin syndrome

Most serious side effect of SSRI

RARE

Symptoms: abdominal pain, diarrhea, fever, sweating, hypertension, tachycardia, spasms, irritability

Treatment: stop SSRI for 2 weeks

NaSSA

Increases norepinephrine and serotonin transmission

Improves sleep, less effect on libido, fewer GI symptoms, weight gain

Mirtazapine

NDRI

Inhibits reputable of norepinephrine and dopamine

Used for smoking cessation, ADHD, and narcolepsy

Can cause weight loss and tremors

Bupropion

SARI

Partial agonist of serotonin and dopamine receptors

Weight gain and aka this is

Rexulti

SNRI

Increase both serotonin and norepinephrine

May cause hypertension

Drugs: pristique, cymbalta, Effexor, fetzima

SPARI

Inhibits serotonin transporter therefore releasing more serotonin

Viibryd

TCA

tricyclic antidepressant

Blocks norepinephrine and serotonin reputable preventing degrading of the MAO enzyme

Blocks muscadine acetylcholine (blurred vision, drey mouth, urine retention etc)

Takes longer to become therapeutic

Drugs: elavil, norpramin, pamelor, tofranil

MAOI's

Nardil, parnate, marplan

Nursing considerations for antidepressants

Asses and monitor for suicidal ideation

Monitor vitals, and I/O

Administer carefully as ordered

Provide frequent patient education

mood stabilizers Lithium

Believe to alter electrical conductivity

Causes GI upset, tremors, confusion, polyuria, edema, seizures, death

Therapeutic levels must be monitored

Narrow index (0.6-1.2 eq/L)

Anticonvulsants for mood disorders

Alter electric conductivity in membranes

Mixed episodes with rapid cycling

Birth defects and hepatic failure

Dry mouth, sedation, rash

Rash can be symptom of Steven Johnson syndrome (tegrtol)

1st gen antipsychotics

Strong antagonists that bind to dopamine receptors and reduce transmission

Side effects: weight gain, sedation, endocrine issues, sexual dysfunction

Most effective on positive symptoms like delusions and hallucinations

1st gen antipsychotics drugs

Hal doll

Haldol decanoate: injectable and long lasting

Thorazine: prisons and last to be used & cheap

extrapyramidal symptoms

acute dystonia (abnormal movement of body)

Akathisia (quivering)

Tardive dyskinesia (repetitive involuntary movements)

Drugs to treat: Benadryl, arcane, cogentin

Neuroleptic Malignant Syndrome

Life threatening emergency

Excessive blockage of dopamine at receptor site

Symptoms: muscle rigidty, fever, decrease responsiveness

Treatment: reduce fever, IV fluids, ICU care

Complications; DVT or organ failure

2nd gen antipsychotics

target positive and negative symptoms

Increased risk for metabolic syndrome

2nd gen antipsychotics drugs

Abilify, clozaril, fanapt, zyprexa, invega, seroquel, risperdal, geodon, Latuda, saphris

Thirds gen antipsychotics

Dopamine stabilizers

Subset of 2nd gen

Abilify, rexulti, vraylar

Clozapine (Clozaril)

1st atypical, Blocks DA receptors in mesolimbic system. SE: drowsy, sedation, hypersalivation, convulsions, suppress bone marrow & induce agranulocytosis. Monitor WBC 6 months.