Olanzapine Health Dictionary

Olanzapine: From 2 Different Sources


An antipsychotic drug used for the treatment of schizophrenia.
Health Source: BMA Medical Dictionary
Author: The British Medical Association

Schizophrenia

An overall title for a group of psychiatric disorders typ?ed by disturbances in thinking, behaviour and emotional response. Despite its inaccurate colloquial description as ‘split personality’, schizophrenia should not be confused with MULTIPLE PERSONALITY DISORDER. The illness is disabling, running a protracted course that usually results in ill-health and, often, personality change. Schizophrenia is really a collection of symptoms and signs, but there is no speci?c diagnostic test for it. Similarity in the early stages to other mental disorders, such as MANIC DEPRESSION, means that the diagnosis may not be con?rmed until its response to treatment and its outcome can be assessed and other diseases excluded.

Causes There is an inherited element: parents, children or siblings of schizophrenic sufferers have a one in ten chance of developing the disorder; a twin has a 50 per cent chance if the other twin has schizophrenia. Some BRAIN disorders such as temporal lobe EPILEPSY, tumours and ENCEPHALITIS seem to be linked with schizophrenia. Certain drugs – for example, AMPHETAMINES – can precipitate schizophrenia and DOPAMINE-blocking drugs often relieve schizophrenic symptoms. Stress may worsen schizophrenia and recreational drugs may trigger an attack.

Symptoms These usually develop gradually until the individual’s behaviour becomes so distrubing or debilitating that work, relationships and basic activities such as eating and sleeping are interrupted. The patient may have disturbed perception with auditory HALLUCINATIONS, illogical thought-processes and DELUSIONS; low-key emotions (‘?at affect’); a sense of being invaded or controlled by outside forces; a lack of INSIGHT and inability to acknowledge reality; lethargy and/or agitation; a disrespect for personal appearance and hygiene; and a tendency to act strangely. Violence is rare although some sufferers commit violent acts which they believe their ‘inner voices’ have commanded.

Relatives and friends may try to cope with the affected person at home, but as severe episodes may last several months and require regular administration of powerful drugs – patients are not always good at taking their medication

– hospital admission may be necessary.

Treatment So far there is no cure for schizophrenia. Since the 1950s, however, a group of drugs called antipsychotics – also described as NEUROLEPTICS or major tranquillisers – have relieved ?orid symptoms such as thought disorder, hallucinations and delusions as well as preventing relapses, thus allowing many people to leave psychiatric hospitals and live more independently outside. Only some of these drugs have a tranquillising e?ect, but their sedative properties can calm patients with an acute attack. CHLORPROMAZINE is one such drug and is commonly used when treatment starts or to deal with an emergency. Halperidol, tri?uoperazine and pimozide are other drugs in the group; these have less sedative effects so are useful in treating those whose prominent symptoms are apathy and lethargy.

The antipsychotics’ mode of action is by blocking the activity of DOPAMINE, the chemical messenger in the brain that is faulty in schizophrenia. The drugs quicken the onset and prolong the remission of the disorder, and it is very important that patients take them inde?nitely. This is easier to ensure when a patient is in hospital or in a stable domestic environment.

CLOZAPINE – a newer, atypical antipsychotic drug – is used for treating schizophrenic patients unresponsive to, or intolerant of, conventional antipsychotics. It may cause AGRANULOCYTOSIS and use is con?ned to patients registered with the Clorazil (the drug’s registered name) Patient Monitoring Service. Amisulpride, olanzapine, quetiapine, risperidone, sertindole and zotepine are other antipsychotic drugs described as ‘atypical’ by the British National Formulary; they may be better tolerated than other antipsychotics, and their varying properties mean that they can be targeted at patients with a particular grouping of symptoms. They should, however, be used with caution.

The welcome long-term shift of mentally ill patients from large hospitals to community care (often in small units) has, because of a lack of resources, led to some schizophrenic patients not being properly supervised with the result that they fail to take their medication regularly. This leads to a recurrence of symptoms and there have been occasional episodes of such patients in community care becoming a danger to themselves and to the public.

The antipsychotic drugs are powerful agents and have a range of potentially troubling side-effects. These include blurred vision, constipation, dizziness, dry mouth, limb restlessness, shaking, sti?ness, weight gain, and in the long term, TARDIVE DYSKINESIA (abnormal movements and walking) which affects about 20 per cent of those under treatment. Some drugs can be given by long-term depot injection: these include compounds of ?upenthixol, zuclopenthixol and haloperidol.

Prognosis About 25 per cent of sufferers recover fully from their ?rst attack. Another 25 per cent are disabled by chronic schizophrenia, never recover and are unable to live independently. The remainder are between these extremes. There is a high risk of suicide.... schizophrenia

Akathisia

n. a pattern of involuntary movements induced by medication, for example *antipsychotic drugs or (more rarely) antidepressants. An affected person is driven to restless overactivity, which can be confused with the agitation for which the drug was originally prescribed. Akathisia is mostly felt as restless legs (see restless legs syndrome) rather than generalized agitation or anxiety. Antipsychotics are the main cause of akathisia but the severity depends on their affinity to *dopamine receptors. In a recent systematic review haloperidol, zotepine, and chlorpromazine were most likely to cause akathisia, with olanzapine least likely, and clozapine causing no akathisia at all. See also extrapyramidal effects.... akathisia

Antipsychotic

n. any one of a group of drugs used to treat severe mental disorders (psychoses), including schizophrenia and mania; some are administered in small doses to relieve anxiety and tic disorders or to treat impulsivity in *emotionally unstable personality disorder. Formerly called major tranquillizers, and later typical and atypical antipsychotics, they are now known as first- and second-generation antipsychotics. The first-generation (or typical) antipsychotics include the *phenothiazines (e.g. *chlorpromazine), *butyrophenones (e.g. *haloperidol), and thioxanthenes (e.g. *flupentixol). Side-effects of antipsychotic drugs can include *extrapyramidal effects, sedation, *antimuscarinic effects, weight gain, and *long QT syndrome. The second-generation (or atypical) antipsychotics are a group of more recently developed drugs that are in theory associated with fewer extrapyramidal effects than first-generation antipsychotics: they include *clozapine, *risperidone, amisulpride, aripiprazole, olanzapine, and quetiapine. Antipsychotics act on various neurotransmitter receptors in the brain, including dopamine, histamine, serotonin, and cholinergic receptors. Most of them block neurotransmitter activity, but some have partially agonistic effects. Recent evidence suggests that there are significant differences among the second-generation antipsychotics regarding their efficacy and side-effect profiles. Clozapine, amisulpride, and olanzapine were found to be the most effective antipsychotics. Clozapine, zotepine, and olanzapine caused the most weight gain; haloperidol, zotepine, and chlorpromazine caused the most extrapyramidal side-effects; sertindole, amisulpride, and ziprasidone caused the most QT-prolongation; and clozapine, zotepine, and chlorpromazine caused the most sedation.... antipsychotic



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