aqa  A2 Option: Drug therapy: typical and atypical antipsychotics

edexcel  One biological treatment for schizophrenia

CIE  A2 Option: Biochemical (antipsychotics and atypical antipsychotics); electro-convulsive therapy. 

tabsDrug Therapy

The Biological Approach explains mental disorders in terms of abnormalities of the central nervous system, i.e. that there is something wrong with the workings of the brain. For example, Schizophrenia has been explained as being caused by an excess of the neurotransmitter dopamine. This suggests that drugs which alter levels of the various neurotransmitters, by blocking receptor sites, inhibiting re-uptake or improving the breakdown of molecules following release for example may be effective in alleviating symptoms.

Typical Anti-Psychotics

Chlorpromazine

Antipsychotics are the primary medications for treating Schizophrenia. Early or Typical Antipsychotics were introduced in the 1950’s and all had similar ability to relieve the positive symptoms of Schizophrenia. This medicine reduces disturbing symptoms like hallucinations and delusions. Typical Antipsychotics help relieve the positive symptoms of Schizophrenia by helping to correct an imbalance in dopamine levels.

Doctors will usually prescribe a Typical Anti-psychotic medication, such as Chlorpromazine, following the first psychotic episode of Schizophrenia. There are many Typical drugs available. Drug treatments need to be started quickly in order to be most effective, and those patients who remain untreated for many years often do not benefit when treatments is finally started.

Effective? Appropriate?

Effective? The early antipsychotics were not perfect and they only seemed to work for around 75 per cent of people diagnosed with schizophrenia. Many psychiatric patients were able to leave hospital and attempt to resume their normal lives. The medication usually reduced the positive symptoms of schizophrenia.

Side effects: A number of problems emerged with the use of these drugs, especially in the form of undesirable side effects. Those for whom the drug worked reported feeling apathetic (they had no enthusiasm for anything), and that they were experiencing dry mouth and gastrointestinal problems. It was also discovered that long-term use of these medications increased the risk of patients experiencing depression.

Long-term, serious side effects: Tardive Dyskinesia: This disorder frequently appears after long-term or high-dose use of Typical antipsychotic drugs. Tardive Dyskinesia is characterised by repetitive, involuntary, purposeless movements, such as grimacing, tongue protrusion, lip smacking, puckering and pursing of the lips, and rapid eye blinking. Rapid movements of the extremities may also occur. It is estimated that 30 per cent of patients develop Tardive Dyskinesia within the first two years of treatment with a typical anti-psychotic.

Atypical Anti-Psychotics

Clozapine

Atypical drugs affect Dopamine and Serotonin. In the last two decades new “atypical” antipsychotics have been introduced. Compared to the older “conventional” antipsychotics these medications appear to be at least equally effective for helping reduce the positive symptoms like hallucinations and delusions – but may be better than the older medications at relieving the negative symptoms of the illness, such as withdrawal, thinking problems, and lack of energy. There is however no concrete evidence of how effective they are at relieving negative symptoms. If symptoms do not improve with the use of typical anti-psychotics, then an Atypical anti-psychotic such as Clozapine might be used.

Effective? Appropriate?

Effective? Clozapine was the first atypical antipsychotic in the United States and seems to be one of the most effective medications, particularly for people who have not responded well to other medications. “Treatment-resistant schizophrenia” is a term used for the failure of symptoms to respond satisfactorily to at least two different antipsychotics. For other patients who are unwilling or unable to take medication regularly, long-acting depot preparations of antipsychotics may be given every two weeks to achieve control. America and Australia are two countries with laws allowing the forced administration of this type of medication on those who refuse but are otherwise stable and living in the community.

Side Effects: Clozapine (only) does not lead to Tardive Dyskinesia. However, in some people it has a serious side effect of dramatically lowering the number of white blood cells produced (Agranulocytosis). People taking Clozapine must have their blood monitored every one or two weeks to count the number of white blood cells in the bloodstream. For this reason Clozapine is usually the last atypical antipsychotic prescribed, and is usually used as a last line treatment for people that do not respond well to other medications or have frequent relapses. Clozapine also seems to induce weight gain in patients, which impacts on their quality of life.

Evaluation of Drug Therapies

Cause & Effect: Drug treatments only treat the symptoms of the disorder, as opposed to the cause. As soon as patients stop taking their medication, their symptoms return. This means that theoretically patients will need to be on medication for the rest of their lives, which is not only inconvenient, but requires continued compliance.

Compliance: Some patients refuse to comply with drug treatment regimes, possibly because of the side effects or sometimes because of poor memory. Research has indicated that if antipsychotics are stopped abruptly, then symptoms re-occur (Davis et al., 1993). This has led to the ‘revolving door syndrome’ of continual discharge into the community, followed by readmission to hospital. One way of avoiding this is to provide depot antipsychotic medication. This is a special preparation of medication, which is usually given by injection into a large muscle (usually the buttock) so as to lessen any discomfort and swelling. These injections release slowly into the body over a number of weeks. The main advantage is that they only need to be given at intervals (up to a month), which means that the patient does not have to remember to take several tablets a day.

Ethical issues: Some people have criticised whether the widespread use of drugs in the treatment of mental disorders is appropriate, referring to them as ‘chemical straight-jackets’. The argument is that the drugs are dehumanising and take away any sense of personal responsibility or control. The ethical issue of informed consent is also a consideration. People in a psychotic state are not really in a position to give truly informed consent about their treatment.


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