Underuse of Clozapine
Clozapine is widely recognised as being underused with wide variation in prescribing, especially in patients with African heritage.Psychiatrists prescribing practices have been found to be the most significant variable regarding variance in its use. Surveys of psychiatrists attitudes to clozapine have found that many had little experience in its use, over estimated the incidence and were fearful of side effects, and did not appreciate that many patients prefer to take clozapine than other antipsychotics, are reluctant to prescribe clozapine, had little experience in its use and believed that patients treated with clozapine were less satisfied than those treated with other antipsychotics. In contrast to many psychiatrists expectations most patients believe that the blood testing and other difficulties are worth the multiple benefits that they perceive. Whilst psychiatrists fear the severe adverse effects such as agranulocytosis, patients are more concerned about hypersalivation. Clozapine is no longer actively marketed and this may also be one of the explanations for its underuse.Despite the strong evidence and universal endorsement by national and international treatment guidelines and the experiences of patients themselves, most people eligible for clozapine are not treated with it. A large study in England found that approximately 30% of those eligible for clozapine were being treated with it. Those patients that do start clozapine usually face prolonged delay, multiple episodes of psychosis and treatments such as high dose antipsychotics or polypharmacy. Instead of two previous antipsychotics many will have been exposed to ten or more drugs which were not effective.
Clozapine is a psychiatric medication and is the first atypical antipsychotic (also called second-generation antipsychotic). It is primarily used to treat people with schizophrenia and schizoaffective disorders who have had an inadequate response to other antipsychotics or who have been unable to tolerate other drugs due to extrapyramidal side effects. It is also used for the treatment of psychosis in Parkinsons disease. Clozapine is regarded as the gold-standard treatment when other medication has been insufficiently effective and its use is recommended by multiple international treatment guidelines, after resistance to earlier neuroleptic treatment is established.The role of clozapine in treatment-resistant schizophrenia was established by a 1988 landmark study in which clozapine showed marked benefits compared to chlorpromazine in a group of patients with protracted psychosis who had already shown an inadequate response to other antipsychotics. While there are significant side effects, clozapine remains the most effective treatment when one or more other antipsychotics have had an inadequate response. The use of clozapine is associated with multiple improved outcomes, including a reduced rate of all-cause mortality, suicide and hospitalization. In a 2013 network comparative meta-analysis of 15 antipsychotic drugs, clozapine was found to be significantly more effective than all other drugs. In a 2021 UK study, the majority of patients (over 85% of respondents) who took clozapine preferred it to their previous therapies, felt better on it and wanted to keep taking it.