Pharmacotherapy of Schizophrenia

PST 06106

Basic Pharmacotherapy

Session 26: Pharmacotherapy of Schizophrenia

Learning Objectives

By the end of this session students are expected to be able to:

Define schizophrenia

Explain pathophysiology of schizophrenia

Explain the clinical presentation of schizophrenia

Outline diagnosis of schizophrenia

Describe pharmacological treatment of schizophrenia

Describe the monitoring of schizophrenia therapy

Activity: Buzzing

What is Schizophrenia

?

Definition of Schizophrenia

Schizophrenia

Schizophrenia is a chronic and severe mental disorder characterised by

disorganized and bizarre thoughts, delusions, hallucinations, inappropriate affect, and impaired psychosocial functioning

Pathophysiology of Schizophrenia

The pathophysiology of schizophrenia is complex.

A number of theories attempt to explain the link between altered brain function and schizophrenia, including;

T

he

Dopamine

hypothesis

The

Glutamate

hypothesis

Neurodevelopmental model

Pathophysiology of

Schizophrenia Cont…

The Dopamine Hypothesis

The first formulations of the dopamine hypothesis of schizophrenia came from post-mortem studies finding increased striatal availability of D

2

/D

3

receptors in the striatum, as well as studies finding elevated CSF levels of dopamine metabolites.

Psychotic symptoms are related to dopaminergic hyperactivity in the brain. Hyperactivity of dopaminergic systems during schizophrenia is result of increased sensitivity and density of dopamine D2 receptors in the different parts of the brain.

Pathophysiology of Schizophrenia Cont…

The glutamate hypothesis

In humans, NMDA receptor antagonists such as phencyclidine, ketamine and

dizocilpine

can produce both positive and negative psychotic symptoms-in contrast to amphetamine which produces only positive symptoms.

It has therefore been postulated that schizophrenia may result from disruption of glutamatergic neurotransmission, evident as a reduction in the function of NMDA receptors

Pathophysiology of Schizophrenia Cont

…..

Neurodevelopmental model

Neurodevelopmental

model supposes in schizophrenia the presence of “silent lesion” in the brain, mostly in the parts, important for the development of integration (frontal, parietal and temporal), which is caused by different factors (genetic, inborn, infection, trauma) during very early development of the brain in prenatal or early postnatal period of life.

It does not interfere too much with the basic brain functioning in early years, but expresses itself in the time, when the subject is stressed by demands of growing needs for integration, during formative years in adolescence and young

adulthood

Clinical presentation of schizophrenia

The symptoms of schizophrenia fall into three categories:

P

ositive

,

Negative,

Cognitive.

Clinical presentation of

schizophrenia Cont.…

Positive symptoms:

“

Positive” symptoms are psychotic behaviors not generally seen in healthy people.

People with positive symptoms may “lose touch” with some aspects of reality.

Symptoms include:

Hallucinations

Delusions

Thought disorders (unusual or dysfunctional ways of thinking)

Movement

disorders (agitated body movements)

Clinical

presentation of schizophrenia Cont.…

Negative symptoms:

“

Negative” symptoms are associated with disruptions to normal emotions and behaviors.

Symptoms include:

“Flat affect” (reduced expression of emotions via facial expression or voice tone)

Reduced feelings of pleasure in everyday life

Difficulty beginning and sustaining activities

Reduced

speaking

Clinical presentation of schizophrenia Cont.…

Cognitive symptoms:

For

some patients, the cognitive symptoms of schizophrenia are subtle, but for others, they are more severe and patients may notice changes in their memory or other aspects of thinking.

Symptoms include:

Poor “executive functioning” (the ability to understand information and use it to make decisions)

Trouble focusing or paying attention

Problems with “working memory” (the ability to use information immediately after learning it)

Diagnosis of Schizophrenia

The Diagnostic and Statistical Manual of the American Psychiatric Association, text revision (DSM-IV-TR), is the guide for diagnosing and classifying schizophrenia and other psychiatric disorders

Diagnosis of

Schizophrenia Cont…

Many patients demonstrate both positive and negative symptoms.

Patients with negative symptoms frequently have more antecedent cognitive dysfunction, poor premorbid adjustment, low level of educational achievement, and a poorer overall prognosis.

Differential diagnosis has to be made in order to exclude other psychiatric conditions that resembles schizophrenia as indicated in the table below

;

Differential Diagnosis Of Schizophrenia

Activity

: Small Group Discussion

What

is the treatment of

Schizophrenia

?

Pharmacological Treatment Of Schizophrenia

The treatment falls under Acute Phase and

Maintenance Phase

Acute Phase

AND

OR

needed.

OR

needed

Pharmacological Treatment Of

Schizophrenia Cont….

If haloperidol is unavailable give;

If patient is known to suffer from schizophrenia and is not neuroleptic naïve give:

If patient develops acute dystonia give:

OR

Anticholinergic agent, e.g

.

Biperiden

.

Pharmacological

Treatment Of Schizophrenia Cont….

For maintenance:

Haloperidol

OR

OR

Olanzepine 5–10mg (PO). Maximum dose 25mg/day

OR

Risperidone 1mg (PO) 12 hourly then increase by 1mg every 2–3 days to 2–3mg 12 hourly. Maximum dose 16mg/day 7

Monitoring of Schizophrenia Therapy

Monitoring parameters for patients with Schizophrenia focuses on three general areas:

Improvement of four positive symptoms which are suspiciousness, hallucinations, unusual thought contents and conceptual disorganization

Improvement of negative symptoms such as prolonged time to respond, emotion including unchanging facial expression, blank, expressionless face, reduced social drive, poor grooming and hygiene

Cognition

Monitoring of Schizophrenia

Therapy Cont..

Pharmacotherapeutic plan should include specific monitoring parameters for side effects.

Given the risk of weight gain, diabetes, and lipid abnormalities associated with many of the

Antipsychotics, baseline

parameters should be taken before beginning antipsychotics:

F

amily

history,

W

eight

,

H

eight

,

B

ody

mass index

,

Monitoring of Schizophrenia Therapy Cont..

Waist circumference,

Blood pressure,

Fasting plasma glucose, and

Fasting lipid profile.

Then follow-up monitoring of these parameters should be done after beginning or changing antipsychotics

.

Key Points

Schizophrenia

is a chronic and severe mental disorder characterised by

disorganized and bizarre thoughts, delusions, hallucinations, inappropriate affect, and impaired psychosocial functioning

The symptoms of schizophrenia fall into three categories which are positive, negative, and cognitive

The treatment of Schizophrenia falls under Acute Phase and

Maintainance

Phase of the disease using typical or atypical antipsychotics.

Evaluation

What

is Schizophrenia?

What is the pathophysiology of

Schizophrenia?

What are the signs and symptoms of Schizophrenia?

How is the treatment of Schizophrenia?

References

Wells

BG,

DiPiro

J,

Schwinghammer

T (2013),

Pharmacotherapy Handbook

(6

th

Ed). New York, NY: McGraw-Hill.

DiPiro

JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey ML, (2008):

Pharmacotherapy: A Pathophysiologic Approach

(7

th

ed

): New York, NY: McGraw-Hill.

Katz M D., Matthias KR., Chisholm-Burns M A., Pharmacotherapy(2011)

Principles & Practice Study Guide: A Case-Based Care Plan Approach

: New York, NY: McGraw-Hill.

Schwinghammer

TL, Koehler JM (2009)

Pharmacotherapy Casebook: A Patient-Focused Approach

(7

th

ed

): New York, NY: McGraw-Hill.

Unataka kutumiwa notes hizi kupitia WhatsApp?Kwa notes zilizopangiliwa vizuri kwa kusoma offline au PDF, bonyeza kitufe hapa chini. Ujumbe wenye Level, Semester, Module na Topic utaandaliwa moja kwa moja.TUMIWA NOTES WHATSAPP