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C H A P T E R 2 2 Psychotherapeutic agents

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).

(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 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.

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

Drug therapy across the lifespan

BOX 22.1

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.