• Journal of Korean Neuropsychiatric Association
• /
• v.57 no.3
• /
• pp.230-234
• /
• 2018

A large proportion of patients with schizophrenia show a poor response to first-line antipsychotic drugs, which is termed treatment-resistant schizophrenia. Previous studies found that a different neurobiology might underlie treatment-resistant schizophrenia, which necessitates the development of different therapeutic approaches for treating treatment-resistant schizophrenia. This study reviewed previous studies on the pathophysiology of treatment-resistant schizophrenia and the pharmacological intervention, and forthcoming investigations of treatment-resistant schizophrenia are suggested.

• Korean Journal of Schizophrenia Research
• /
• v.24 no.1
• /
• pp.1-7
• /
• 2021

Clozapine is the first and most effective atypical antipsychotic drug for treatment-resistant schizophrenia (TRS). After withdrawal of clozapine due to concerns of agranulocytosis, clozapine was reintroduced with a comprehensive safety monitoring system, the clozapine patient monitoring system (CPMS). The reintroduction was a response to the pressure from psychiatrists and patients with TRS and their families. Clozapine is still the best single agent for the treatment of TRS. However, approximately 30% of patients with TRS still show psychotic symptoms. In patients with clozapine-resistant schizophrenia (CRS), augmentation of other antipsychotic agents could be considered after a thorough evaluation of proper clozapine treatment. In this review, the status of clozapine in patients with TRS and CRS will be discussed.

• Korean Journal of Schizophrenia Research
• /
• v.23 no.2
• /
• pp.51-57
• /
• 2020

Treatment-resistant schizophrenia (TRS) has been defined as the persistence of positive symptoms despite two or more trials of antipsychotic medication of adequate dose and duration. TRS is a serious clinical problem and occurs in approximately 30% of patients with schizophrenia. It is important that patients who do not adequately respond to antipsychotics be reevaluated to exclude or address causes other than non-responsiveness to medication, that is, the possibility of pseudo-resistance. In particular, non-adherence to oral antipsychotic treatment should be monitored to rule out pseudo-resistant cases of TRS. Moreover, patients with TRS who take their medication as required may have subtherapeutic antipsychotic plasma levels, secondary to pharmacokinetic factors. In this paper, we review the concept and exclusion of pseudo-resistance, especially owing to non-adherence or pharmacokinetic factors, and present methods to enhance drug adherence.

• Korean Journal of Schizophrenia Research
• /
• v.23 no.2
• /
• pp.45-50
• /
• 2020

Schizophrenia is one of serious mental illnesses and is often described as a heterogeneous disorder. Approximately one-third of schizophrenia cases are treatment-resistant schizophrenia (TRS). The aim of this study was to review the definitions and clinical features of TRS. Though it was found that the criteria for TRS were considerably diverse, the Treatment Response and Resistance in Psychosis (TRRIP) consensus criteria were recently introduced. According to the TRRIP criteria, TRS should be suspected if symptoms persist alongside psychotic symptoms despite sufficient treatment for ≥12 weeks, or two or more symptoms persist significantly for ≥6 weeks. The clinical characteristics of TRS includes an earlier age of onset, more severe and familial form, possibly more rural residence, unlikely association with male sex, and an increase in cognitive deficits.

• Korean Journal of Biological Psychiatry
• /
• v.16 no.3
• /
• pp.170-180
• /
• 2009

Objectives : To assess clinical improvement and change in plasma brain-derived neurotrophic factor(BDNF) level after repetitive transcranial magnetic stimulation(rTMS) in patients with treatment-resistant schizophrenia. Methods : Seven patients with DSM-IV schizophrenia, who were proven to be treatment-resistant, were treated with 15 sessions of rTMS for three weeks as an adjuvant therapy to antipsychotic treatment. Clinical improvement and change in plasma BDNF level were measured after the treatment period. The symptom severity was assessed with the Positive and Negative Syndrome Scale(PANSS) and the Korean Version of Calgary Depression Scale for Schizophrenia(K-CDSS) at baseline and 7 days after the treatment. Plasma BDNF level was measured by enzyme-linked immunosorbent assay(ELISA) at baseline and 7 days after the treatment. Results : After the rTMS treatment, there was no significant improvement in PANSS total score(Z=-1.693, p=0.090) and no significant change in plasma BDNF was found(Z=-1.183, p=0.237). Negative correlations were found between percentage change in PANSS positive subscale score and duration of illness(rho=-0.991, N=7, p<0.0005, two-tailed), and PANSS negative subscale score at baseline and percentage change in plasma BDNF level(rho=-0.821, N=7, p=0.023, two-tailed). Conclusion : This preliminary study suggests that rTMS didn't make a significant change in clinical symptoms nor in plasma BDNF level in treatment-resistant schizophrenia. Percentage change in plasma BDNF, however, might be correlated with treatment resistance in schizophrenic patients. This is a pilot study with a small sample size, therefore, a further study with a larger sample size is needed.

• Korean Journal of Schizophrenia Research
• /
• v.24 no.2
• /
• pp.52-59
• /
• 2021

Objectives: Recent studies have reported that delayed initiation of clozapine can affect clinical response in patients with treatment-resistant schizophrenia (TRS). This study aimed to explore the relationship between delayed initiation of clozapine and acute treatment response. Methods: Sixty-five inpatients with TRS who started clozapine for the first time were included through a retrospective chart review. Acute treatment response was defined as a 30% reduction in the Positive and Negative Syndrome Scale score or a Clinical Global Impression of Improvement score of 1 (very much improved) or 2 (much improved) at 4 weeks after initiating clozapine. Results: After meeting the TRS criteria, the mean delay for initiating clozapine was approximately 13.8 months. The delay was shorter in patients who showed a better response to clozapine in logistic regression analysis (p=0.037). Conclusion: Our findings suggest that reducing the delay in initiating clozapine increases the effectiveness of clozapine in patients with TRS.

• Korean Journal of Biological Psychiatry
• /
• v.12 no.2
• /
• pp.151-158
• /
• 2005

Background:Clozapine is a unique atypical antipsychotic medication. It is considered to be superior, even amongst the newer agents, in treatment-resistant schizophrenia. However, de novo emergence or exacerbation of obsessive-compulsive(OC) symptoms during treatment with clozapine has been reported. We prospectively evaluated 19 cases which newly developed OC symptoms during clozapine treatment and discussed the treatment of OC symptoms induced by it. Methods:We recruited 19 patients(8 males, 11 females) with a DSM-IV diagnosis of schizophrenia and schizoaffective disorder who had developed OC symptoms during clozapine treatment. OC symptoms were assessed using the Padua-ICMA and YBOCS on a monthly basis over three months. Results:Eleven female and eight male patients were enrolled and the average age of patients was 32.8 years. At baseline, no patients showed OC symptoms. Moderate to severe OC symptoms appeared with mean daily dose of 298.68 mg of clozapine. There were no significant differences in improving OC symptoms between the clozapine dose reduction group and the OC treatment group. Conclusion:We noticed the possibility that the appearance of OC symptoms is connected with the effect of clozapine. The clozapine-induced OC symptoms were improved both by reducing clozapine daily doses, and by adding OC treatment drugs. With other atypical antipsychotics now available, to know and treat the side effects of clozapine would be of considerable value, offering clinical guidance in making a decision on treatment-resistant schizophrenia.

• Korean Journal of Schizophrenia Research
• /
• v.22 no.1
• /
• pp.1-7
• /
• 2019

Objectives: Clozapine is the drug of choice in treatment-resistant schizophrenia. However, its use is often delayed and a significant proportion of clozapine treated patients fails to respond and experience potentially dangerous side-effects. The aim of this retrospective study was to describe the clinical characteristics of patients started on clozapine and the rate and reason of discontinuation of clozapine. Methods: Medical records of 83 patients started on clozapine during the period of 2012-2016 were reviewed. Results: Clozapine started on patients in chronic phase; the mean age of start was 38.1 years old and the mean number of psychiatric admission was 6.5. A majority (80.7%) of the patients had been subjected to antipsychotic polypharmacy prior to clozapine and most (61.5%) of them were being treated with polypharmacy including clozapine. Overall, 39 (47.0%) subjects had continued clozapine whereas 15 (18.1%) discontinued it; 29 (34.9%) were lost to follow-up. The most common reason for discontinuation was side-effects (n=13) including six life-threatening cases, most of which occurred within 6 months of its start. Conclusion: This study demonstrated that there is some evidence of delays to clozapine use, high rates of polypharmacy and significant rate of discontinuation during the early phase of clozapine treatment.

• Korean Journal of Biological Psychiatry
• /
• v.28 no.2
• /
• pp.50-57
• /
• 2021

Objectives Clozapine is the most effective atypical antipsychotic agent for the treatment-resistant schizophrenia (TRS), however, only 40%-70% of TRS patients respond to clozapine. Moreover, TRS encompasses various symptom dimensions. Therefore, augmentation with other medications for clozapine is frequently applied. However, the prescription pattern of clozapine and combined medications in Korea is yet to be examined. This study aims to investigate the maintenance treatment pattern of clozapine and augmentation agents in one Korean tertiary hospital. Methods The patients with schizophrenia spectrum disorders under clozapine maintenance, defined as one-year clozapine continuation, were subjected for analysis. Medication data at one-year time-point after clozapine initiation was extracted and analyzed. Results Among total 2897 patients having clozapine prescription experience from January 2000 to December 2018, 1011 patients were on clozapine maintenance. The mean age of clozapine initiation was 30.2 ± 11.3 years, and the maintenance dose of clozapine was 217.8 ± 124.3 mg/day. Combination rate of antipsychotics, mood stabilizers, and antidepressants were 43.5%, 25.3%, 38.6%, respectively. Most frequently prescribed drugs in each category were aripiprazole, valproate, and sertraline. Olanzapine equivalent dose of combined antipsychotics was 10.4 ± 7.7 mg/day. Male patients were prescribed higher dose of combined antipsychotics and higher rate of antidepressants. Female patients had later onset of clozapine prescription. Patients with two or more combined antipsychotics were prescribed higher dose of clozapine and higher rate of antidepressants compared to patients with one combined antipsychotic. Conclusions Taken together, among the patients taking clozapine, a substantial rate of patients were under polypharmacy. The present findings based on the real-world prescription pattern could provide the valuable clinical information on the treatment of TRS-related conditions.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.9 no.1
• /
• pp.98-104
• /
• 1998

A 12-year-old girl with a 6 year history of childhood-onset schizophrenia required 2 hospitalizations and long-term clozapine trial due to inadequate responses to combinations of typical neuroleptics and traditional treatments of schizophrenic disorder. On admission, she had continuous auditory and visual hallucinations, persecutory delusion, emotional instability, regression of behaviors including temper tantrums as well as specific developmental delays in learning, language, and motor coordination. The clozapine trial significantly reduced most of the positive symptoms, and facilitated in successful discharge from the hospital. During the 4 year clozapine treatment, no significant adverse reactions were noted, and she returned to a structured school setting with minimal degrees of schizophrenic symptoms. From this clinical experience, we suggest that clozapine might be safe and effective in treating treatment-refractory schizophrenic children.