Psychopharmacology

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Psychopharmacology

• Rebecca Sposato MS, RN

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A busy brain

• Receive, process and analyze stimuli (touch,
  sound, sights, smells, taste)
• Use data to construct thoughts and emotions
• Receive and produce communication
• Physiological regulation
• Move muscles
• Remember things

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Brain Anatomy

• Brain Stem Physiological regulation, instincts,
  emotion
• Cerebellum Motor coordination and balance
• Cerebrum thoughts, emotions, memories, sensory
  data and movement
• White matter cell bodies at surface Gray
  matter cell wires interconnecting
• Lobes sensory data and decisions
• Hippocampus/Amygdala emotions, memory
• Basal Ganglia movement

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Brain Diagnostics

• Structural Imaging
• Magnetic Resonance Imaging (MRI) and Computed
  Tomography (CT)-
• Shows structures and shapes of tissues, presence
  of solids, liquids, gasses
• Functional Imaging
• Functional-MRI
• Tagged blood for detecting oxygenation levels
• Positron Emission Tomography (PET)
• Shows uptake of glucose by brain cells revealing
  where the location of active brain cells

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Parts of a Neuron

• Switching the location of sodium and potassium
  ions sends an electrically charged signal (the
  action potential) down the axon
• Normally, potassium is concentrated inside the
  cell and sodium outside the cell until the neuron
  opens its channels on the cell wall and the two
  trade places for a microsecond
• Signals only travel in one direction because the
  channels quickly close

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Synapse

• The space where one neuron can start a signal in
  the next neuron
• Each neuron manufactures only one type of
  neurotransmitter and its corresponding enzyme
• When the action potential reaches the terminal
  button, the vesicles migrate to the cells
  surface and drop the neurotransmitters into the
  synapse and triggers the next neuron
• Psychoactive drugs influence one step of this
  process to increase or decrease the firing of its
  neuron

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Neuroconduction

• http//www.youtube.com/watch?v90cj4NX87Yk
• http//www.youtube.com/watch?vifD1YG07fB8NR1

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Pharmacology Terms

• PharmacoDYNAMICS how the drug affects the body
• The drugs action on the targeted cells
• The other cells involved
• PharmacoKINETICS how the body affects the drug
• How the body absorbs, stores, moves, destroys and
  eliminates the drug
• Most often the liver and kidney play a part
• Therapeutic Index median effective/median
  adverse or lethal
• The blood level between 50 of users feeling
  better and 50 of users feeling worse

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Pharmacology Terms

• Tolerance lower effectiveness of medication at
  current dose level
• Withdrawal unpleasant psychological and physical
  symptoms experienced when a chemical is abruptly
  stopped
• Blood Brain Barrier cerebral capillaries have
  very few pores
• hinders most WATER soluble molecules from
  crossing between blood and brain tissue
• LIPID soluble molecules can cross
• Some medications (sinemet) must saturate proteins
  in the blood (albumin) to have enough molecules
  in the plasma to enter brain

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Anti-anxiety Medications

• Glutamate tells your neuron to thrill,
  gamma-aminobutyric acid (GABA) tells your neuron
  to chill (GABA can control Na or K channels)
• Benzodiazepines ativan (lorazepam), valium
  (diazepam), klonopin (clonazepam), and xanax
  (alprazolam). Controlled substances
• indirect agonist (mimics) for GABAa, attaches to
  the same binding site (without blocking it)
• Treats seizures, withdrawal symptoms, anxiety

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Precautions for Benzodiazepines

• Impairs attention and motor coordination (ataxia)
• Due to GABA receptors in the cerebellum
• More dramatically in the elderly fall risk
• In higher doses can also mimic the effects of
  GABA in the brain stem leading to sedation
• Increased affect when combined with alcohol,
  opiates, and tricyclic anti-depressants

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Insomnia Medications

• Sedative/Hypnotics Zolpidem (Ambien), temazepam
  (restoril), Zaleplon (Sonata), and Eszopiclone
  (Lunesta)
• Act on a more specific sub-group of GABA
  receptors, promotes sleep but do treat anxiety
• Not recommended for long term use
• Side effects amnesia, ataxia, unusual sleeping
  behaviors (walking, eating etc.)

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Insomnia Medications - melatonin

• Melatonin a hormone secreted when dark by the
  pineal gland (b/t midbrain and cerebellum),
  involved in seasonal and circadian rhythms by
  acting upon the suprachiasmatic nucleus (SCN) the
  brains clock
• Ramelton (Rozerem) melatonin receptor agonist
  (mimics)
• Not a controlled substance and can be used long
  term

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The alternative anxiolytic

• Buspar (buspirone) approved to treat mild to
  moderate anxiety as partial serotonin agonist
  with a mild influence on dopamine-2
• Does NOT act upon GABA, less sedation compared to
  benzodiazemines

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Monoamine Oxidase Inhibitors (MAO-I)

• MAO the presynaptic enzyme that destroys
  recently reabsorbed serotonin, nor/epinephrine,
  dopamine
• Inhibitors stop the enzyme from destroying the
  neurotransmitters, increasing their supply in the
  synapse
• MAO also works in the liver to break down
  tyramine, a chemical in food that tells your
  blood vessels to SQUEEZE
• Not liked, rarely used
• Diet restrictions cheese, wine, smoked fish
• Interferes w/ other meds

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Tricyclic Antidepressants (TCA)

• Block to reuptake of norepinephrine or
  norepinephrine and serotonin
• Amitriptyline (elavil), nortriptyline (pamelor)
• Narrow therapeutic range
• Side action block muscarinic (named after a
  mushroom) receptors for acetylcholine

Anticholinergic side effects pupil dilation,
confusion, urinary retention, increase HR
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Selective Serotonin Reuptake Inhibitors (SSRI)

• Popular anti-depressant
• Prozac, Celexa, Luvox, Zoloft, Paxil
• http//www.youtube.com/watch?vocSptPUBbuo
• Block re-absorption of serotonin by the
  PRE-synaptic neuron, re-exciting the
  POST-synaptic neuron
• Serotonin correlates with feeling content

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Adverse Affects of SSRI

• Common Weight gain, impaired sexual arousal
• Terotogenic pulmonary HTN in newborn, heart
  defects, etc.
• Bleeding risk inhibits platelet coagulation
• Serotonin Syndrome caused by combining
  serotonin-acting medications
• Mild restless, sweaty, tachy
• Moderate HTN, hyperthermia, rigid, lethargic
• Severe Seizures, shock and coma
• Serotonin discontinuation Syndrome- abruptly
  stopping after long term use
• GI symptoms, malaise, moody etc.

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Alternative Anti-depressants

• Wellbutrin (Bupronion)/Zyban blocks reuptake of
  dopamine and norepinephrine
• May treat smoking withdrawal side action of
  inhibiting nicotinic acetylcholine receptors
• Lowers the seizure threshold

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Lithium

• The element is in the same column on the periodic
  table of elements as Na and K
• Makes neurons less excitable
• Influences the conduction of neurons though its
  influence on Na
• Reduce effect of glutamate
• Mood Stability in bipolar disorder
• Reduction in number and severity of manic
  episodes, improves depression

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Precautions with lithium

• Narrow therapeutic range, lithium toxicity
  threatens all conductive activity in the body
• Long term use may damage thyroid
• Goiter, hypothyroid
• Low sodium enhances the toxicity of lithium
• Signs of toxicity (gt1.5)
• Tremor, confusion, N/V/D, arrhythmias, polyuria,
  polydipsia, edema

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Anti-Convulsants

• Work through their anti-conductive properties on
  neurons to stabilize mood
• Carbamazine (tegretol) affects sodium channels
  to reduce firing, prevent and treat mania
• Side effects anticholinergic, ataxia,
  orthostatic BP, rash,
• Valporate (depakote) increases GABA to treat
  both manic and depression features of bipolar
  disorder
• Side effects tremor, weight gain, sedation
• Serious side effects Fetal encephalopathy,
  thrombocytopenia, pancreatitis, hepatic disease
• Check drug levels, CBC, liver panel

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More anti-convulsants

• Lamotrigine (lamictal) - blocks Na channel,
  preventing the release of glutamate and aspartate
• prevent mania (does NOT treat acute mania),
  improves depression
• Rashes may progress to Steven Johnson syndrome

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Classic antipsychotics

• Chlorpormazine (thorazine)and Haldol
  (haloperidol) 1950s, 1st psych meds
• Very broad acting blocks dopamine among other
  neurotransmitters (histamine, nor/epinephrine and
  acetylcholine) to treat positive symptoms of
  schizophrenia and psychoses
• Anticholinergic side effects
• Stops dopamines role in the hormone prolactins
  feedback loop, increase levels lead to
  feminization
• Extra-pyramidal side effects abnormal,
  involuntary and repetitive facial/neck movements
• AIMS score http//www.youtube.com/watch?vFUr8ltX
  h1Pc

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Atypical Antipsychotics

• Treats both negative and positive symptoms of
  schizophrenia
• Action is more specific to dopamine yielding
  fewer and EPS and anti-cholinergic side effects
• Many affect the pancreas leading to insulin
  resistance
• Clozaril- block dopamine in the limbic system
• Convulsions, bone marrow suppression, low WBC
• Risperdone- some EPS and weight gain, orthostatic
  BP, CVA risk in elderly
• Seroquel (quetiapine) - blocks dopamine,
  histamines, epinephrine and serotonin
• sedation

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More anti-psychotics

• Olanzapine (Zyprexa) attaches to specific
  serotonin and dopamine receptors
• Sedation and metabolic syndrome
• Apriprzole (Abilify) creates more level
  dopamine levels in the cerebrum

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psychostimulants

• Ritalin (methylphenidate), Adderall
  (dextroamphetamines) controlled substances
• Increase levels of dopamine and norepinephrine by
  inhibiting their reuptake
• Increase alertness and attention
• Paradoxical in ADHD/ADD
• Stratterra (atomoxetine) selective
  norepinephrine reuptake inhibitor
• Non-stimulant option for ADHD/ADD

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Anti-dementia

• Aricept (donezepil), galantamine (reminyl)
• Interfere with acetylcholinesterase (the enzyme
  that breaks down Acetylcholine in the
  post-synaptic neuron ) increasing its
  concentration in the synapse
• Mematine (Namenda) blocks the N-methyl-d-aspartate
  receptor, preventing glutamate from opening the
  Ca channels and the resulting corrosion

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Herbals/Dietary Supplements

• NCCAM NIH office for alternative medicine
• DSHEA dietary supplement health and education
  act (1994) law states dietary supplements and
  herbals do NOT need FDA approval before being
  sold
• FDA may intervene if product causes harm to
  consumer