C H A P T E R 2 2
Psychotherapeutic agents
335
T
he drugs discussed in this chapter are used to treat psy-
choses—perceptual and behavioural disorders. These
psychotherapeutic agents are targeted at thought pro-
cesses rather than affective states. Although they do not
cure any psychotic disorders, psychotherapeutic agents
do help both adults and children to function in a more
acceptable manner and carry on activities of daily living
(Box 22.1).
MENTAL DISORDERS AND THEIR
CLASSIFICATION
Mental disorders were once attributed to environmental
influences and life experiences such as poor parenting
or trauma. Mental disorders are now thought to be
caused by some inherent dysfunction within the brain
that leads to abnormal thought processes and responses.
Most theories attribute these disorders to some sort of
chemical imbalance in specific areas within the brain.
Diagnosis of a mental disorder is often based on distin-
guishing characteristics as described in the
Diagnostic
and Statistical Manual of Mental Disorders,
5th edition
(DSM-V). Because no diagnostic laboratory tests are
available, assessment and response must be carefully
evaluated to determine the basis of a particular problem.
Selected disorders are discussed here.
Schizophrenia
, the most common type of psy-
chosis, can be very debilitating and prevents affected
individuals from functioning in society. Characteris-
tics of schizophrenia include hallucinations, paranoia,
delusions, speech abnormalities and affective problems.
This disorder, which seems to have a very strong genetic
association, may reflect a fundamental biochemical
abnormality.
Mania
, with its associated bipolar illness (i.e. manic-
depressive illness), is characterised by periods of
extreme overactivity and excitement.
Bipolar disorder
involves extremes of depression alternating with hyper-
activity and excitement. This condition may reflect a
biochemical imbalance followed by overcompensation
on the part of neurons and their inability to re-establish
stability.
Narcolepsy
is characterised by daytime sleepiness
and sudden periods of loss of wakefulness. This disorder
may reflect problems with stimulation of the brain by
BOX 22.1
Drug therapy across the lifespan
Psychotherapeutic agents
CHILDREN
Many of these agents are used in children, often in
combination with other central nervous system (CNS)
drugs in an attempt to control symptoms and behaviour.
Long-term effects of many of these agents are not known
and parents should be informed of this fact.
Of the antipsychotics, chlorpromazine, haloperidol,
prochlorperazine, risperidone and trifluoperazine are
the only ones with established paediatric regimens.
Aripiprazole has doses for children 13 to 17 years of age.
The dose is often higher than that required for adults.The
child should be monitored carefully for adverse effects and
developmental progress.
Lithium does not have a recommended paediatric dose
and the drug should not ordinarily be used in children. If
it is used, the dose should be carefully calculated from the
child’s age and weight, and the child should be monitored
very closely for renal, CNS, cardiovascular and endocrine
function.
The CNS stimulants are often used in children to
manage various attention-deficit disorders. Caution should
be used with extended-release preparations because
they differ markedly in timing and effectiveness.The child
should be assessed carefully and challenged periodically
for the necessity of continuing the drug.
ADULTS
Adults using these drugs should be under regular
care and should be monitored regularly for adverse
effects.The QT
c
interval should be evaluated before
thioridazine or ziprasidone is prescribed and
periodically during use.
People receiving lithium should be encouraged
to maintain hydration and salt intake.They need to
understand the importance of periodic monitoring of
serum lithium levels.
PREGNANCY AND BREASTFEEDING
These drugs should be used very cautiously during
pregnancy and breastfeeding because of the potential for
adverse effects on the fetus or neonate. A woman maintained
on one of these drugs needs to be counselled about the risk
to the fetus versus the risk of returning symptoms if the drug
is stopped. Use should be reserved for situations in which
the benefits to the mother far outweigh the potential risks
to the neonate.Women of childbearing age who need to
take lithium should be advised to use barrier contraceptives
while taking the drug because of the potential for serious
congenital abnormalities.
OLDER ADULTS
Older people may be more susceptible to the adverse
effects of these drugs. All doses need to be reduced and
people monitored very closely for toxic effects and to
provide safety measures if CNS effects do occur.They
should not be used to control behaviour with dementia.
People with renal impairment should be monitored
very closely while taking lithium. Decreased doses may
be needed. Because many older people may also have
renal impairment, they need to be screened carefully.They
should be urged to maintain hydration and salt intake,
which can be a challenge with some older people.
Prolongation of the QT
c
interval—associated with
use of ziprasidone—may be a concern in elderly people
with coronary disease. Careful screening and monitoring
should be done if these drugs are needed for such people.
