PSYCHOPHARMACOLOGY -TINU TOMY

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PSYCHOPHARMACOLOGY

• PRESENTED BY
• TINU TOMY
• MSc. Psychology

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Pharmacology

• Pharmacology (from Greek pharmakon, "poison in
  classic Greek drug in modern Greek" and ,
  "Study of" -logia) is the branch of medicine and
  biology concerned with the study of drug action.
  More specifically, it is the study of the
  interactions that occur between a living organism
  and chemicals that affect normal or abnormal
  biochemical function. If substances have
  medicinal properties, they are considered
  pharmaceuticals. The field encompasses drug
  composition and properties, interactions
  toxicology therapy, and medical applications and
  antipathogenic capabilities.

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DRUGS

• It is a single active chemical entity present in
  the medicine that is used for diagnosis ,
  treatment prevention of disease
• Drug nomenclature
• Chemical name
• Non- propriety name
• Propriety name

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Mechanism of drug action

• Pharmacokinetics
• Absorption
• Distribution
• Biotransformation/metabolism
• Excretion

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Routes of administration

• Intravenous (I/V)
• Intramuscular(I/M)
• Subcutaneous (s/c)
• Intradermal (I/D)
• Sublingual (S/L)
• Oral
• Topical application

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Bioavailability

• Bioavailability refers to the portion of a drug
  absorbed from the site of administration

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Pharmacodynamics-what the drug does to the body

• Physical action
• Chemical action
• Through enzymes
• Through receptors

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Some important terms

• Dose response relationship
• Therapeutic window phenomenon
• Therapeutic range
• Combined effect of drugs (synergism antagonism)
• Cumulation
• Tolerance( natural, acquired, cross tolerance)

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Half-Life

• Half-life is the time needed to clear 50 of a
  drug from the plasma. It also determines the
  length of time necessary to reach steady state.
  The general rule is that the time to reach
  steady-state concentration (C SS) of a drug is
  five times the drug's half-life, not five times
  the dosing interval. The reason is that during
  every half-life period, a patient either clears
  or accumulates 50 of the eventual C SS produced
  by that dosing rate

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Steady-State

• It is that total concentration of a drug in
  plasma that will not change as long as the dosing
  rate (i.e., dose per interval of time) remains
  unchanged or
• other factors do not alter the rate of metabolism
  or elimination .

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Zero and First Order Kinetics

• When only a fixed amount of drug is eliminated in
  a given interval of time, because enzymes for
  biotransformation and elimination are saturated,
  the kinetics of drug elimination are zero order.
• First order kinetics means that the amount
  eliminated per unit of time is directly
  proportional to the amount ingested, so there is
  a linear relationship between dose change and
  plasma level change (i.e., 11). In contrast,
  with zero order kinetics there is a larger than
  proportional increase in the plasma concentration
  for each dose increment because the elimination
  mechanism is saturated.

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THERAPEUTIC DRUG MONITORING

• TDM can detect interindividual variability in
  pharmacokinetics that can determine clinical
  outcome .
• Role of Therapeutic Drug Monitoring
• One role for TDM is to guard against toxicity.
  This fact is particularly true for drugs that
  have narrow therapeutic indices, serious toxic
  effects, and substantial inter individual
  variability in metabolism. Such drugs include
  bupropion, clozapine, lithium, TCAs, some
  anticonvulsants, and low-potency antipsychotics.
  This role is especially crucial when early signs
  of toxicity are difficult to detect.

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Adverse drug reaction

• Side effects
• Secondary effects toxic effects
• Intolerance
• Idiosyncrasy
• Drug allergy
• Drug dependence(psychological physical)

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PRINCIPLES OF PSYCHOPHARMACOTHERAPY

• The diagnostic assessment, subject to revisions,
  is fundamental to our model
• Pharmacotherapy alone is generally insufficient
  for complete recovery
• The phase of an illness (e.g., acute, relapse,
  recurrence) is of critical importance in terms of
  the initial intervention and the duration of
  treatment

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• The risk-to-benefit ratio must always be
  considered when developing a treatment strategy
• Prior personal (and possibly family) history of a
  good or a poor response to a specific agent
  usually dictates the first-line choice for a
  subsequent episode.
• It is important to target specific symptoms that
  serve as markers for the underlying
  psychopathology and to monitor their presence or
  absence over an entire course of treatment.
• It is necessary to watch for the development of
  adverse effects throughout the entire course of
  treatment. Such monitoring often involves the use
  of the laboratory to ensure safety, as well as
  optimal efficacy (6).

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• Drug legislation and safety
• In the United States, the Food and
  DrugAdministration (FDA) is responsible for
  creating guidelines for the approval and use of
  drugs. The FDA requires that all approved drugs
  fulfill two requirements
• The drug must be found to be effective against
  the disease for which it is seeking approval.
• The drug must meet safety criteria by being
  subject to extensive animal and controlled human
  testing.

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DRUG MANAGEMENT

• Acute, Maintenance, and Prophylactic Therapy
• Because most psychiatric disorders are recurrent
  and chronic in nature, appropriate management
  always requires the consideration of three phases
  of treatment
• Acute, or the control of a current episode
• Maintenance, or the prevention of relapse -once
  an acute episode has been alleviated and it is
  assumed that the acute disease process has been
  suppressed but is still present
• Prophylactic, or the prevention of future
  episodic exacerbations

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Antianxiety agents
Name Half life(hrs) Adult dose(mg)
Benzodiazepines
Alprazolam 6-26 .75-4
Chlordiazepoxide 5-30 15-100
Clonazepam 18-50 1.5-20
Clorazepate 40-50 15-60
Diazepam 20-80 4-40
Lorazepam 10-20 2-6
Oxazepam 5-20 30-120
Propanediols
meprobamate 6-17 400-2400
azaspirodecanediones
buspirone 2-11 15-60
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SEDATIVE HYPNOICS AGENTS
BARBITURATES Dose(mg) Half life(hr)
AMOBARBITAL 60-200 16-14
BUTABARBITAL 45-120 66-140
MEPHOBARBITAL 32-200 11-67
PENTOBARBITAL 60-100 15-50
PHENOBAEBITAL 30-200 53-118
SECOBARBITAL 100-200 15-40
BENZIDIAZEPINES
ESTAZOLAM 100-200 15-40
FLURAZEPAM 15-30 2-3
QUAZEPAM 7.5-15 41
TEMAZEPAM 15-30 9-15
TRIAZOLAM .125-.5 1.5-5.5
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• MISCELLANEOUS
• CHLORAL HYDATE
• ESCOPICLONE
• ZALEPLONE
• ZOLPIDEM

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Unwanted effects

• tiredness,
• drowsiness,
• torporso-called over-sedation'.
• Psychomotor performance is also affected
• Other unwanted effects include respiratory
  depression, excessive weight gain, skin rash,
  impairment of sexual function, menstrual
  irregularities, and, rarely, blood dyscrasias.

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Withdrawal symptoms

• The mildest symptoms and signs are anxiety,
  tension, apprehension, dizziness, tremulousness,
  insomnia, and anorexia. More severe physical
  dependence is shown by the withdrawal symptoms of
  nausea and vomiting, severe tremor, muscle
  weakness, postural hypotension, and tachycardia.
  Occasionally, hyperthermia, muscle twitches,
  convulsions, and confusional psychoses may
  develop.

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Antidepressants

• Antidepressant drugs fall into a wide variety of
  chemical classes and they have a wide range of
  neuro pharmacological effects
• Major anti depressents are
• Tricyclics and tetracyclics
• SSRI
• MAO inhibitors

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Tricyclics and tetracyclics
Tricyclic Dose(mg)
Amitriptyline 50-300
Clomipramine 25-250
Doxepine 25-300
Imipramine 30-300
Trimipramine 50-300
Nortriptyline 30-100
Protriptyline 15-60
Tetracyclics
Amoxapine 50-600
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Indication

• Major depressive disorder
• Panic disorder with agoraphobia
• Generalized anxiety disorder
• OCD
• Pain Mx

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Adverse effects

• Psychological
• Anticholinergic
• Cardiac
• Other autonomic effects
• Sedation
• Neurological
• Photosensitivity
• Weight gain

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Interactions

• MAO INHIBITORS
• Antihypertensive
• CNS depressants
• Antipsychotics
• SSRI
• Valproic acid

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SSRIs(selective serotonin reuptake inhibitors)
Name Dose(mg)
Citalopram 20-60
Fluoxetine 20-80
Fluvoxamine 50-300
Escitalopram 10-20
Paroxetine 10-50
Sertraline 50-200
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Indications

• Depression
• Suicide
• Anxiety disorders
• Bulimia nervosa
• Premenstrual dysphoric disorder
• Off label uses-premature ejaculation,
  paraphilias, autism.

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Adverse effects

• Insomnia
• Agitation
• Headache
• Weight loss
• sexual dysfunction
• Serotonin syndrome

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Interactions

• SSRI
• MAOIs
• Tricyclics
• Antipsychotics
• B-blockers
• Carbamazepine
• Theophylline
• warfarin

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MAOIs(Monoamino oxodase inhibitors)
Name Dose(mg)
Isocarbixazide 20-60
Phenelzine 45-90
tranylcypromine 30-60
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Indications

• Depression
• Panic disorders
• Anginal pain
• Depression associated with traumatic brain injury

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Adverse effects

• Orthostatic hypotension
• Insomnia
• Weight gain
• Edema
• Sexual dysfunction
• Paresthesias, myoclonus,
• Muscle pain
• Hepato toxicity
• Tyramine induced hypertensive crisis
• Contra indicated in pregnancy and nursing mothers

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Antipsychotics

• Used in the treatment of acute and chronic
  psychosis, particularly when accompanied by
  increased psychomotor activity.
• divided into two categories
• Typical/first generation/traditional/conventional
• Atypical

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• Typical antipsychotic drugs are those which
  produce extrapyramidal side-effects at clinically
  effective doses in the majority of patients.
  Extrapyramidal side-effects include parkinsonism
  (muscle rigidity, loss of associated movements),
  acute dystonic reactions, dyskinesias, akathisia
  (restlessness), and tardive dyskinesia. They are
  also called neuroleptics because of their
  inhibitory effect upon locomotion activity.
  Atypical antipsychotic drugs are those with a
  significantly lower propensity to produce
  extrapyramidal side-effects at clinically
  effective doses.(1) They are sometimes referred
  to as novel antipsychotic drugs, reflecting the
  later development of most of these compounds
  (with the exception of clozapine) or by their
  pharmacology, for example multireceptor
  antagonists or serotonin (5-hydroxytryptamine) 2A
  antagonists.(

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Typical antipsychotics
NAMEthiothexene DOSE(mg)
PHENOTHIAZINES
Chlorpromazine 200-800
Acetophenazine 40-120
Fluphenazine 2-60
Perphanazine 8-32
trifuoperazine 5-20
Mesordazine besylate 75-300
Thioridazine 150-800
THIOXANTHENES
Thiothexene 5-30
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DIBENZOXAPINE
Loxapine 40-100
DIHYDROINDOLE
Molindole 50-225
BUTYROPHENONE
Haloperidol 5-30
DIPHENYLBUTYLPIPERIDINE
Pimozide 2-6

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Indications

• Acute psychotic episode as in schizophrenia and
  schizo affective disordes(also in maintenance
  phase)
• Mania
• Depression with psychotic features
• Delutional disorders
• Borderline personality disorders
• Delirium and dementia
• PDD

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Adverse effects

• CNS
• Alpha adrenergic blockade
• Anticholinergic
• Endocrine
• Extra pyramidal disturbances
• miscellaneous

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Atypical antipsychotics (also called serotonin
dopamine antagonist/second generation
antipsychotics)
Name Dose(mg)
Dibenzodiazepine
Clozapine 100-900
Quetiapine 150-600
Benzisoxazole
Risperidone 4-8
Ziprasidone 40-160
Thionobenzodiazepine
Olanzapine 10-20
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Features of SDAs

• Low D2 receptor blocking effect
• Reduced risk of extra pyramidal side effect
• Proved efficacy as treatment of choice for
  schizophrenia and acute mania

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Mood stabilizers
antimanic Dose(mg) Therapeutic plasma level
Lithium carbonate Acute mania-1800-2400 Maintenance- 900-1200 Acute mania- 1-1.5mEq/mL Maintenance- .6-1.2mEq/mL
anticonvulsants
Clonazepam .75-16 20-80ng/mL
Carbamazepine 200-1200 4-12micro gram/L
Valproic acid 500-1500 50-100microgm/mL
Lamotrigine 100-200
Gabapentin 900-1800
Topiramate 50-400
Calcium channel blocker
verapami 80-320 80-300ng/mL
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Antiparkinsonian agents

• ANTICHOLINERTGICS
• BENZOTROPINE
• BIPERIDEN
• PROCYCLIDINE
• TRIHEXYPHENIDYL
• ANTIHISTAMINES
• DIPHENHYDRAMINE
• DOPAMINERGIC AGONIST
• AMANTADINE

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THANK YOU