Transcript PY 440 Psychopharmacology Basics

Psychopharmacology
Basics
An important aspect of
treatment of emotional
disorders is with
psychotherapeutic
medications.
Compared to other types of
treatment, these medications
are relative newcomers in the
fight against mental illness.
People who, years
ago, might have spent
many years in mental
hospitals because of
crippling mental
illness may now only
go in for brief
treatment, or might
receive all their
treatment at an
outpatient clinic.
Symptom Relief, Not Cure
Just as aspirin can reduce a fever without
clearing up the infection that causes it,
psychotherapeutic medications act by
controlling symptoms.
Like most drugs used in medicine, they
correct or compensate for some
malfunction in the body.
Psychotherapeutic medications do not
cure mental illness, but they do lessen its
burden.
Like any medication,
psychotherapeutic medications
do not produce the same effect in
everyone.
Some people may respond better
to one medication than another.
Some may need larger dosages
than others do.
Pharmacology offers hope
to many who would
otherwise have a dismal
prognosis.
Pharmacology: Study of Drugs
• Drug: any substance that when
administered to a living organism
• Produces a change in function
• Water, metals (iron) or insecticidies
can be classified as drugs
• In common usage, the term DRUG
refers to any medication used to
treat disease.
Pharmacology Divisions
• Pharmacodynamics: study of drugs on
living tissue
• Pharmacotherpeutics: study of use of
drugs in treating disease
• Posology: study of the amount of drug
required to produce therapeutic effects
• Pharmacy: science of preparing and
dispensing medications
• Toxicology: study of harmful effects of
drugs of living tissue
Clinical Psychopharmacology –
concerned mainly with the use
of drugs to treat abnormal
human behavior.
Where do drugs come from?
• Plants
• Animals
• Synthetic: produced in labs
What actually is a drug?
• A chemical compound with a
specific chemical structure
• Receptor site: specific area on a cell
membrane where drug attaches self.
Binding = drug action.
• Agonists: produces drug action
• Antagonists: blocks drug action
No drug produces only ONE
effect
• Intended (or therapeutic) effect
along with several other effects
• Side effects
• Side effects generally not harmful
unless TOXIC
Drug Safety
• The federal
•
FOOD and DRUG
ADMINISTRATION
FDA
• has established guidelines governing the
approval and use of all drugs
• Public safety is priority
• Every drug must fill two
requirements before used in
humans:
–Must be effective in the
disease state for which
approved
–Must not produce toxic effects
at therapeutic doses
What is a clinical trial?
• A clinical trial is a research study to
answer specific questions about
vaccines or new therapies or new ways
of using known treatments.
• Clinical trials (also called medical
research and research studies) are used
to determine whether new drugs or
treatments are both safe and effective.
• Carefully conducted clinical trials are
the fastest and safest way to find
treatments that work.
• Ideas for clinical trials usually come
from researchers.
• Once researchers test new therapies
or procedures in the laboratory and
get promising results, they begin
planning Phase I clinical trials.
• New therapies are tested on people
only after laboratory and animal
studies show promising results
What is a protocol?
• All clinical trials are based on a set of
rules called a protocol.
• A protocol describes what types of people
may participate in the trial; the schedule
of tests, procedures, medications,and
dosages; and the length of the study.
• While in a clinical trial,participants are
seen regularly by the research staff to
monitor their health and to determine the
safety and effectiveness of their treatment
What are clinical trial phases?
• Clinical trials of experimental drugs proceed
through four phases:
• In Phase I clinical trials, researchers test a new
drug or treatment in a small group of people
(20-80) for the first time to evaluate its safety,
determine a safe dosage range, and identify side
effects.
• In Phase II clinical trials, the study drug or
treatment is given to a larger group of people
(100-300) to see if it is effective and to further
evaluate its safety.
• In Phase III studies, the study drug or
treatment is given to large groups of people
(1,000-3,000) to confirm its effectiveness,
monitor side effects, compare it to commonly
used treatments, and collect information that
will allow the drug or treatment to be used
safely.
• Phase IV studies are done after the drug or
treatment has been marketed. These studies
continue testing the study drug or treatment
to collect information about their effect in
various populations and any side effects
associated with long-term use.
What is a control or control
group?
• A control is the standard by which
experimental observations are
evaluated.
• In many clinical trials, one group of
patients will be given an experimental
drug or treatment,while the control
group is given either a standard
treatment for the illness or a placebo.
What is a placebo?
• A placebo is an inactive pill, liquid, or
powder that has no treatment value.
• In clinical trials, experimental treatments
are often compared with placebos to
assess the treatment's effectiveness.
• In some studies, the participants in the
control group will receive a placebo
instead of an active drug or treatment
What is a blinded or masked study?
• A blinded or masked study is one in which
participants do not know whether they are
in the experimental or control group in a
research study.
• Those in the experimental group get the
medications or treatments being tested,
while those in the control group get a
standard treatment or no treatment
What is a double-blind or doublemasked study?
• Neither the participants nor the study
staff
• know which participants are receiving the
experimental treatment
• and which ones are getting either a
standard treatment or a placebo.
• These studies are performed so neither the
patients' nor the doctors' expectations
• about the experimental drug can influence the
outcome.
Safety….
• Before approved for humans, drugs must
undergo several years of animal (several species)
testing and evaluation
• LD50: Lethal dose 50, dose that would kill 50%
of animals tested
• Therapeutic Index: TI is ratio of ED50 and LD50
of a drug
TI = LD50 = 1000mg
ED50
=
10
100mg
Used only in animal studies to establish dosage
levels for other testing procedures
Generic Drugs
• Manufacturing medications is
expensive
– Clinical trials process
– Marketing
• Patent expires
• Produced with less restriction
• Usually less expensive
• Effectiveness??????
Basic Concepts of Pharmacology
• Site of action: location
within the body where the
drug exerts its therapeutic
effect.
• Mechanism of action:
explains how the drug
produces its effects
Biological Concepts
• Most drugs in psychopharmacology
affect humans by affecting the
communication between neurons in the
brain.
• To understand these effects, you must
understand something about cell
membranes,
• and the special protein structures in
membranes that regulate the flow of
substances and information in and out
of the cell.
• Then you can understand how this
regulation can result in an electrical
signal which travels down the neuron
• and how this electrical signal can be
transferred between neurons at
synapses,
• where neurotransmitters are released
from one cell
• to affect receptors on another cell.
Biological Concepts
Most drugs in
psychopharmacology work by
affecting the communication
between neurons in the brain.
The brain is made of cells (called
neurons) which communicate with each
other at places called synapses.
A synapse is a functional (but
not physical) contact between
two neurons.
Neuron
Neuron
Synapse
Half Life
Effect
Time
• Neurotransmitters: about 40 known
or suspected neurotransmitters in
the brain.
The following chemicals have been shown to
act as neurotransmitters in the brain:
Dopamine
Norepinepherine
Serotonin
Acetylcholine
Gamma aminobutyric acid (GABA)
Several Amino Acids
Acetylcholine
Two types of receptors-nicotinic receptors and
muscarinic receptors. Nicotinic receptors are on
muscle fibers; both types exist in the central nervous
system.
Found in the brain (mostly excitatory), spinal cord,
ganglia of the autonomic nervous system (mostly
excitatory) and at the target organs of the
parasympathetic branch of the autonomic nervous
system (both excitatory and inhibitory).
Death of acetylcholine neurons is the primary cause of
Alzheimer's Disease.
• Epinephrine (adrenaline)
Drugs that block the activity of
dopaminergic Synthesized by the
adrenal glands.
• Adrenal is Latin for "toward
kidney" and epi nephron is Greek
for "upon the kidney."
• Dopamine
Implicated in movement, attention
neurons alleviate psychotic symptoms,
leading to speculation that schizophrenia
is caused by dopaminergic overactivity.
• Cocaine and amphetamine work at
dopaminergic synapses to increase
activity, and prolonged or excessive
exposure to amphetamine or cocaine can
result in acute psychosis.
• Norepinephrine
Most noradrinergic synapses in the
CNS.
• At the target organs of the
sympathetic nervous system,
norepinephrine produces EPSPs.
• Serotonin
Plays a role in the regulation of mood,
in the control of eating, sleep and
arousal, and in the regulation of pain.
• Drugs which inhibit serotonin
increase dreaming and can cause
hallucinations (LSD).
Anti-depressants……..
• can be roughly categorized into groups,
depending upon their chemical
structure and the way they work
• 1) tricyclics and tetracyclics (TCA's);
• 2) monoamine oxidase inhibitors
(MAOI's);
• 3) serotonin-specific reuptake inhibitors
(SSRI's);
• miscellaneous.
Commonly Rx Tetracyclics/Tricyclics
• amitriptyline
(Elavil, Endep, Enden, Tryptizol)
amitriptyline +
(perphenazine, Etrafon, Triavil)
amoxapine
(Asendin)
clomipramine
(Anafranil)
desipramine
(Norpramine, Pertofrane)
doxepin
(Adapin, Sinequan)
imipramine
(Tofranil, Janimine)
maprotiline
(Ludiomil)
nortriptyline
(Pamelor, Ventyl, Aventyl)
protriptyline HCL (Vivactil)
trimipramine
(Surmontil)
•
Serotonin-specific Reuptake
Inhibitors (SSRI's)
• These drugs, along with the tricyclic and
tetracyclic drugs and the MAOI's, are
considered the major antidepressant
drugs;
• they are also effective in a wide range of
disorders, including bipolar I disorder,
dysthymic disorder, eating disorders,
panic disorder, obsessive-compulsive
disorder, and borderline personality
disorder.
• Because they generally have fewer adverse
side effects than other classes of
antidepressants they are more widely
prescribed;
• one SSRI, fluoxetine (Prozac), the least
cardiotoxic of all antidepressants, has
become the most widely prescribed
antidepressant and is one of the top ten
most prescribed drugs in the US.
Commonly RX SSRI’s
• fluoxetine (Prozac)
fluvoxamine (Luvox)
paroxetine (Paxil)
sertraline
(Zoloft)
(Serzone)
(Celexa)
ANTIANXIETY MEDICATIONS
• Formerly called the "minor
tranquilizers", the medicines in this
group are primarily used in the
treatment of anxiety;
• they are also used for some other
disorders, such as depression, panic
disorder, social phobia, bipolar I
disorder, and substance withdrawal.
• Because they have a higher therapeutic index and
less abuse potential, the benzodiazepines
• (which comprise the largest number in this
group) have largely replaced the barbituates in
treatment for these disorders,
and are also widely used a s sedatives and
hypnotics as well as anesthetics, anticonvulsants,
and muscle relaxants.
• Antihistimines are occasionally used to treat
anxiety disorders, as are the beta-blockers.
Commonly Rx Antianxiety
• Alprazolam
(Xanax)
Atenolol
(Tenormin)
buspirone
(BuSpar)
chlordiazepoxide (Librium,
Libritabs, Lipoxide)
clonazepam
(Klonopin)
clonodine
(Catapres)
ANTIPSYCHOTIC
MEDICATIONS
• This group, formerly known as the "major
tranquilizers", or neuroleptics, is comprised
mainly of a set of drugs known as
dopamine-blockers,
• These drugs target the idiopathic psychoses
that have no known cause, such as
schizophrenia, schizophreniform disorder,
schizoaffective disorder, delusional
disorder…………….
• brief psychotic disorder, manic
episodes, and major depressive
disorder with psychotic features,
• as well as being commonly used in
the treatment of patients who are
severely agitated and violent.
• They have a wide application for a
variety of disorders, including
movement disorders, anxiety
disorders, and psychoses that have
organic causes.
• Commonly RX Antipsychotic
• chlorpromazine
fluphenazine
haloperidol
loxapine
mesoridazine
perphenazine
pimozide
risperidone
thioridazine
thiothixene
trifluoperazine
(Thorazine,)
(Prolixin, )
(Haldol)
(Loxitane)
(Serentil)
(Trilafon)
(Orap)
(Risperdal)
(Mellaril)
(Navane)
(Stelazine)
Side Effects
• Potent drugs usually
have potent side effects,
and the antipsychotic
drugs are no
exception!!!
ANTIMANIC MEDICATIONS
• Many of the drugs that have already
been discussed have been found to be
efficacious in effecting mood
regulation or stabilization, such as the
benzodiazepines, carbamazepine,
clozapine, the dopamine receptor
antagonists, lithium, L-tryptophan,
and valproate.
Commonly Rx Antimanics
• diltiazem
(Cardizem)
nifedipine
(Adalat, Procardia)
nimodipine
(Nimotop)
verapamil
(Calan, Isoptin)
lithium carbonate
(Cibalith-S,
Camcolt, Priadel,
Liskonum, Phasal-these are not used in US)
SEDATIVES AND HYPNOTIC
MEDICATIONS
• This class includes the barbituates, which are among the
first drugs to be used in clinical psychiatric treatment,
being introduced in the US in 1903.
• One of the oldest sedative-hypnotic drugs still in use,
chloral hydrate, has been used since 1869.
•
Because of their high abuse potential and
lower therapeutic index, the barbituates are
now less commonly prescribed than the
newer compounds, such as the
benzodiazepines and buspirone, which are
considered much safer.
Side Effects
• A high abuse potential is associated with
these drugs, the barbituates in
particular.
• Drowsiness, confusion, constipation,
blurred vision, edema, vertigo,
paradoxical dysphoria, hyperactivity,
cognitive disorganization, lethargy,
fatigue, headache.
• Many of the adverse side effects are
similar to those of the benzodiazepines
Commonly Rx Sedatives/Hypnotics
• Amobarbital
aprobarbital
butabarbital
chloral hydrate
ethchlorvynol
methohexital
nitrazepam
pentobarbital
phenobarbital
secobarbital
zolpidem
(Amytal)
(Alurate)
(Butisol)
(Noctec)
(Placidyl)
(Brevital)
(Mogadon)
(Nembutal)
(Luminal, Barbita, Solfoton)
(Seconal)
(Ambien)
MEDICATION USED TO OFFSET THE
SIDE EFFECTS OF OTHER MEDICATIONS
• This rather inclusive group
encompasses the anti-parkinsonsism,
anticonvulsant, anticholinergic, sideeffect medicines which target the
neuroleptic-induced movement
disorders, such as………..
• parkinsonism, malignant
syndrome, acute dystonia, acute
akathisia, tardive dyskinesia,
postural tremor and various
other movement disorders that
are
• extrapyramidal side effects
(EPS).
Side Effects
• Oddly enough, medicines that target
side-effects can themselves have sideeffects, such as
• hypotension and bradycardia,
nausea,
• vomiting, diarrhea, and constipation
• anticholinergic effects, abuse
potential, dizziness, insominia,
irritability, depression, anxiety,
nausea,
Commonly Rx
• Anticholinergics and Amantadine
• amantadine
(Symmetrel, Symadine)
benztropine mesylate
(Cogentin)
biperidin
(Akineton)
ethopropazine
(Parsidol)
procyclidine
(Kemadrin)
trihexyphenidyl
(Artane, Tremin,
Trihexane, Trihexy-5)
• Beta-Adrenergic Drugs
• (Beta-blockers)
• atenolol
chlorthalidone
metoprolol
nadolol
propranolol
(Tenormin)
(Tenoretic)
(Lopressor)
(Corgard)
(Inderal)
• Antihistamines
• cyproheptadine
diphenhydramine
Cough,
Hydramine,
Phendry,
Twilite)
bromocriptine
Dantrolene
(Periactin)
(AllerMax, Banophen,
Belix, Benadryl, Dephen
Dormarex-2, Genahist,
Nidryl, Nordryl, Nytol,
Sleep-Eze-3, Sominex 2,
(Parlodel)
Psychostimulants
• MEDICATIONS USED FOR ATTENTION
DEFICIT DISORDER
• This category is devoted almost exclusively
to the amelioration of attentiondeficit/hyperactivity disorder (ADHD)
effects.
• It includes the sympathomimetics,
clonidine, and some of the tricyclic
antidepressants.
Commonly Rx Psychostimulants
• amphetamine
(Benzedrine)
clonidine hydro-chloride
(Catapres)
desipramine HCL
(Norpramin, Pertofrane)
dextroamphetamine
(Dexedrine)
imipramine HCL
(Tofranil, Janimine)
methylphenidate
(Ritalin)
pemoline
(Cylert)
(Adderall)
(Concerta)