Investigators reviewed over 53,000 autopsy records, including over 600 from individuals whose autopsies revealed the presence of the antipsychotics clozapine or olanzapine, and found that those who took clozapine were significantly less likely to have died by suicide, compared with their counterparts who were taking olanzapine.
“Clozapine is an important and effective antisuicide medicine and should be strongly considered for treatment-resistant psychotic disorders, especially when the patient may be at risk for suicide,” study investigator Paul Nestadt, MD, associate professor, department of psychiatry and behavioral sciences, Johns Hopkins School of Medicine, Baltimore, told this news organization.
The study was published online in The Journal of Clinical Psychiatry.
Underutilized medication
Clozapine is the only medication indicated for treatment-resistant schizophrenia and is considered “the most efficacious antipsychotic,” the investigators note. Unfortunately, it has “long been underutilized” for several reasons, including prescriber hesitancy and concerns about side effects.
The authors note that its mechanism of action and the basis for superior efficacy are “still poorly understood” but “may extend beyond neurotransmitter receptor binding.”
Importantly, it may have a beneficial impact on domains other than positive symptoms of schizophrenia, including suicidality. Several studies have shown that it’s beneficial in this regard, but it is “unclear whether the unique antisuicidal properties of clozapine are related to better symptom control ... or to the closer monitoring and follow-up mandated for clozapine use,” they note.
A previous trial, the International Suicide Prevention Trial (InterSePT), demonstrated that clozapine is associated with a greater reduction in suicidality, and the findings “led to an FDA indication for clozapine in reducing the risk of recurrent suicidal behavior.”
However, the authors note, “in the severely ill populations in these studies, it is difficult to be certain about patients’ adherence to prescribed clozapine.”
“Other studies, such as InterSePT, have shown some evidence of clozapine working to reduce suicide-related outcomes, such as attempts or suicidal ideation, but few have been sufficiently powered to measure an effect on actual suicide deaths,” said Dr. Nestadt.
Dr. Paul Nestadt
“As a suicidologist, I feel it is very important that we understand what treatments and interventions can actually prevent suicide deaths, as most suicides are not associated with past attempts or ideation, with suicide decedents usually looking very different from characteristic nonfatal attempters, from a clinical or epidemiological standpoint,” he added.
“If we could show that clozapine actually decreases the likelihood of suicide deaths in our patients, it gives us more reason to choose it over less effective neuroleptics in our clinics – especially for patients at high risk of suicide,” he said.
For the study, the researchers reviewed 19-year state-wide autopsy records of Maryland’s Office of the Chief Medical Examiner, which “performs uniquely comprehensive death investigations.” Data included in these investigations are full toxicologic panels with postmortem blood levels of antipsychotics.
The researchers compared decedents who tested positive for clozapine and decedents who tested positive for olanzapine. They evaluated demographics, clinical features, and manner-of-death outcomes.