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Clozapine is an atypical antipsychotic medication used in the treatment of schizophrenia, and is also sometimes used off-label for the treatment of bipolar disorder and borderline personality disorder. The first of the atypical antipsychotics to be developed, it was first introduced in Europe in 1971, but was voluntarily withdrawn by the manufacturer in 1975 after it was shown to cause agranulocytosis, a condition involving a dangerous decrease in the number of white blood cells, that led to death in some patients. In 1989 after studies demonstrated that it was effective in treating treatment-resistant schizophrenia the United States Food and Drug Administration (FDA) approved the use of clozapine solely for that use, requiring regular white blood cell and absolute neutrophil counts. The FDA also requires clozapine to carry five black box warnings for agranulocytosis, seizures, myocarditis, for "other adverse cardiovascular and respiratory effects", and for "increased mortality in elderly patients with dementia-related psychosis."〔(【引用サイトリンク】title=Clozaril (Clozapine) drug description - FDA approved labeling for prescription drugs and medications at RxList )〕 In 2002 the FDA approved clozapine for reducing the risk of suicidal behavior for patients with schizophrenia. Clozapine is usually used only in patients that have not responded to other anti-psychotic treatments due to its danger of causing agranulocytosis as well as the costs of having to have blood tests continually during treatment. It is, however, one of the most effective anti-psychotic treatment choices.〔(【引用サイトリンク】 What medications are used to treat schizophrenia? )〕 Patients are monitored weekly for the first six months. If there are no low counts the patient can be monitored every two weeks for an additional six months. Afterwards, the patient may qualify for every four-week monitoring. Clozapine has numerous severe side effects including agranulocytosis, and seizures, and has been associated with myocarditis and diabetes though those relationships have not been confirmed. Additionally, it also often causes less serious side effects such as hypersalivation and weight gain. It has one of the least probabilities of causing extrapyramidal side-effects compared to typical antipsychotics. It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system. ==Medical uses== Clozapine is an atypical antipsychotic drug primarily prescribed to patients who are unresponsive to or intolerant of conventional and other atypical neuroleptics.〔MIMS Ireland. April 2007.〕 It is used principally in treating treatment-resistant schizophrenia, a term used for the failure of symptoms to respond satisfactorily to at least two different antipsychotics. It has been shown to be more effective in reducing symptoms of schizophrenia than the older typical antipsychotics, with more pronounced effects in those who have responded poorly to other medication. The relapse rate is lower and patient acceptability is better.〔 There is some evidence clozapine may reduce propensity for substance abuse in schizophrenic patients. There has been one case report of successful use of clozapine in isolated increase in creatine kinase (in absence of neuroleptic malignant syndrome) in a patient with schizophrenia where other atypical antipsychotics were not successful.〔P03-358 Clozapine may be the answer: a case report of elevated serum creatine kinase in the absence of NMS. A. Mohandas, N. Talwar, A. James Langdon Hospital, Devon Partnership NHS Trust, Dawlish, UK 〕 A number of case reports indicate that clozapine can be an effective treatment for schizophrenia while at the same time diminishing some symptoms associated with Parkinson's, such as the tremor and dyskinesia. Unlike typical antipsychotics such as haloperidol and some atypical antipsychotics such as risperidone, clozapine does not produce Parkinsonian symptoms, even at high doses. This is in part because it binds relatively weakly to the D2 dopamine receptor, compared to most other antipsychotics. Clozapine is not approved by the Food and Drug Administration (FDA) for the treatment of behavior problems in older adults with dementia. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Clozapine」の詳細全文を読む スポンサード リンク
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