Indian research: Focus on clozapine

De Novo Seizures, Obsessive Compulsive Symptoms and Neutropenias in Patients on Clozapine: A Retrospective Cohort Study

BACKGROUND

Clozapine has well-documented inter-ethnic variations in pharmacokinetics. There is a paucity of data about clozapine use and associated adverse events such as seizures, obsessive compulsive symptoms, neutropenia, and agranulocytosis, from India.

METHODS

This retrospective cohort study followed up 228 patients initiated on clozapine in a tertiary care referral center in India for an average of 10 years. We calculated incidence rates of new-onset seizures, new-onset obsessive compulsive symptoms, agranulocytosis, and neutropenia. We collected data on doses of clozapine used and serum assays and calculated concentration-to-dose (C/D) ratios. We also collected relevant clinical details about clozapine-induced seizures.

RESULTS

In the sample, 16.8% had new-onset seizures, 12.3% had new-onset OC symptoms, 2.7% had neutropenia, and 0.9% had agranulocytosis. The mean C/D ratio was 2.09 (SD = 1.8). Almost half (46.3%) of available serum assays were in the supra-therapeutic range. Seizures were associated with a higher clozapine dose at one year (OR = 1.003; 95%CI = 1.000-1.006; P value = 0.045) and the presence of positive psychotic symptoms at one year (OR = 4.214; 95%CI = 1.894-9.373; P < 0.001).

CONCLUSION

Compared to existing literature, Indians have a higher rate of clozapine- related seizures and need lower doses to reach therapeutic serum levels.

Clozapine research from India: A systematic review

BACKGROUND

Although clozapine is much researched in western literature, a review on Indian research on clozapine published in 2010 reported limited data and need for further research in this area.

AIM

We aimed to conduct a systematic review of research on clozapine from India from 2010 to mid-2022 and also compare the same with research output before 2010.

METHODOLOGY

A systematic various search engines, i.e., PUBMED, Medknow, Hinari and Google Scholar was done using the key words clozapine and India. Published articles with clozapine in the title and having an author from India, published during 2010 to July 2022 were included.

RESULTS

Initial Internet and hand searches yielded 280 articles, out of which 126 articles were excluded due to various reasons and 154 articles, were included for the review. This included 84 case reports, 49 original articles, 11 review articles and 10 letters to the editor as comments. We found an increase in the number of publications during the period of 2010-2022 compared to 1997-2009 in all types of publications. Over the years a significant proportion of the articles focused on various side effects of clozapine, factors associated with response and non-response to clozapine and evaluation of outcomes other than efficacy/effectiveness. However, all the studies were limited to a single centre with no multicentric studies on clozapine.

CONCLUSION

Over the last 12 years or so, there is increase in the number of publications on clozapine. However, there is lack of multicentric studies.

Cost of the Illness of Treatment-Resistant Schizophrenia: A Mirror Image Study Comparing Clozapine With Other Antipsychotics

PURPOSE/BACKGROUND

This study aimed to evaluate and compare the cost of illness in patients with treatment-resistant schizophrenia (TRS) during 3 months before starting clozapine and for the initial 3 months of treatment with clozapine.

METHODS/PROCEDURES

Fifty-two patients with TRS were evaluated for the cost of illness (direct, indirect, and provider cost) by using a structured questionnaire for the period of 3 months before starting clozapine and then at the end of the 3 months of clozapine therapy.

FINDINGS/RESULTS

Total treatment cost for the period of 3 months before starting clozapine was Indian rupees (INR) 40,372 (560.72 US dollars), and the total treatment cost for the first 3 months of clozapine therapy was INR 40,553 (563.23 US dollars). At both the assessments, indirect cost formed the main bulk of the total cost, with no significant difference in the indirect cost. The total direct treatment cost reduced from INR 13,931.6 (193.49 US dollars) to INR 8756 (121.61 US dollars), and the difference between the 2 assessments was statistically significant, with an advantage for clozapine. Overall, after starting clozapine, the total direct cost reduced from 34.5% to 21.6%, and the total indirect cost reduced from 54.3% to 40.2%. After starting clozapine, total provider cost increased from 11.2% to 38.2% of the totalcost.

IMPLICATIONS/CONCLUSIONS

Treatment with clozapine is not associated with a significant increase in the overall treatment cost, in the short term. However, there is a significant reduction in direct treatment costs.

Clozapine: Why Is It So Uniquely Effective in the Treatment of a Range of Neuropsychiatric Disorders?

Clozapine is superior to other antipsychotics as a therapy for treatment-resistant schizophrenia and schizoaffective disorder with increased risk of suicidal behavior. This drug has also been used in the off-label treatment of bipolar disorder, major depressive disorder (MDD), and Parkinson's disease (PD). Although usually reserved for severe and treatment-refractory cases, it is interesting that electroconvulsive therapy (ECT) has also been used in the treatment of these psychiatric disorders, suggesting some common or related mechanisms. A literature review on the applications of clozapine and electroconvulsive therapy (ECT) to the disorders mentioned above was undertaken, and this narrative review was prepared. Although both treatments have multiple actions, evidence to date suggests that the ability to elicit epileptiform activity and alter EEG activity, to increase neuroplasticity and elevate brain levels of neurotrophic factors, to affect imbalances in the relationship between glutamate and γ-aminobutyric acid (GABA), and to reduce inflammation through effects on neuron-glia interactions are common underlying mechanisms of these two treatments. This evidence may explain why clozapine is effective in a range of neuropsychiatric disorders. Future increased investigations into epigenetic and connectomic changes produced by clozapine and ECT should provide valuable information about these two treatments and the disorders they are used to treat.

Effectiveness of clozapine on quality of life and functioning in patients with treatment-resistant schizophrenia

BACKGROUND

Although it is well known that treatment with clozapine is associated with improvement in core symptoms of schizophrenia, little information is available about its impact on other outcome variables. Accordingly, this study aimed to evaluate the short term (3 months) effectiveness of clozapine in patients with treatment-resistant schizophrenia (TRS) in terms of quality of life, disability, and level of functioning.

METHODS

This naturalistic follow-up study evaluated 52 participants at the baseline and three months (±1 week) after initiation of clozapine (prospective assessment) on Positive and Negative Syndrome Scale for schizophrenia, Calgary Depression Scale for Schizophrenia, Yale-Brown Obsessive-Compulsive Scale Checklist and Scale, Clinical Global Impression (CGI) scale, Beck Cognitive Insight Scale (BCIS), Scale to Assess Unawareness of Mental Disorders (SUMD), Social Occupational Functioning Scale - SOFS, Functioning Assessment Short Test (FAST), Indian Disability Evaluation and Assessment Scale (IDEAS), World Health Organisation Quality Of Life-BREF (WHOQOL-BREF) and Self-report Quality of Life Measure for people with schizophrenia.

RESULTS

Treatment with clozapine led to significant improvement in the quality of life, functioning, and disability; reduction in psychopathology (positive, negative, general psychology, depression), the severity of illness, compulsive behavior, and improvement in insight including cognitive insight.

CONCLUSIONS

Treatment with clozapine leads to improvement in core symptoms of schizophrenia and is also associated with significant improvement in the quality of life, functioning, and disability.

Effect of clozapine on psychological outcomes of caregivers of patients with treatment resistant schizophrenia

BACKGROUND

There is limited information on caregiver outcomes of patients with treatment-resistant schizophrenia (TRS).

AIM

This study aimed to evaluate the impact of short-term treatment with clozapine (i.e. 3 months) on caregiver burden, expressed emotions, caregiver abuse, and psychological morbidity among the caregivers in patients with TRS. 52 caregivers of patients with TRS were evaluated on the Family Burden Interview Schedule, Perceived Criticism Measure, Caregiver Abuse Screening Questionnaire, and General Health Questionnaire-12.

RESULTS

Maximum caregiver burden was seen in the domain of disruption of routine family activities, and this was followed by the domains of disruption of family leisure, disruption of family interaction, and the effect on mental health on others. At the baseline assessment, three-fourth of the caregivers scored ≥12 on the objective burden. With 3 months of clozapine therapy, there was a significant reduction in the caregiver burden in all the domains of objective burden, subjective burden, and the global objective burden as per the clinician rating, in the expressed emotions as per both patients and the caregivers, caregiver abuse, and psychological morbidity among the caregivers.

CONCLUSION

To conclude, this study suggests that caregivers of patients with TRS, experience significantly higher caregiver burden, and a large proportion of them suffer from psychological morbidity and indulge in expressed emotions and abuse of the patient. Treatment with clozapine for 3 months leads to a reduction in the caregiver burden, expressed emotions, caregiver abuse, and psychological morbidity among the caregivers.

ABCB1 and DRD3 polymorphism as a response predicting biomarker and tool for pharmacogenetically guided clozapine dosing in Asian Indian treatment resistant schizophrenia patients

PURPOSE

To investigate association of two single nucleotide polymorphisms (SNPs) ABCB1(rs1045462) and DRD3(rs6280) with clozapine response and the dose in treatment resistant schizophrenia (TRS) patients.

METHODS

200 TRS patients were enrolled in the study during their follow up visit post clozapine initiation. SNP assessment was performed for DRD3 (rs6280) and ABCB1(rs1045462) by sequencing. Blood sample for genotyping was collected with disease and treatment related variables recording on case record form. Patients were classified as responders or nonresponders based upon Andreasen criteria and Positive and Negative Syndrome Scale (PANSS).

RESULTS

Mean clozapine dose, the genotype frequency distribution of ABCB1, DRD3 SNPs were significantly different in clozapine responder and non-responder study population (p < 0.05). CT genotype of ABCB1 and AG genotype of DRD3 were observed to be more prevalent in the responder group. TT genotype of ABCB1 and AG genotype of DRD3 were prevalent in the nonresponder group. Clozapine dosing equations for responder and nonresponder TRS populations were developed through logistic regression analysis. 27% variability in clozapine dose was explained by possible combinations of ABCB1 and DRD3 SNP analysis.

CONCLUSION

Differential ABCB1(rs1045462) and DRD3(rs6280) genotype frequencies among the clozapine responders and non-responders explained clear feasibility of response predictor potential along with clozapine dose variability association. Pharmacogenetically guided clozapine dosing is possible if more SNPs are considered together with ABCB1(rs1045462) and DRD3(rs6280) in TRS patients.

Delay in initiation of clozapine: a retrospective study from a tertiary care hospital in North India

This study aimed to assess the delay in initiation of clozapine, number of adequate antipsychotic trials prior to starting clozapine and practice of polypharmacy prior to starting clozapine. A retrospective study design was followed. Treatment records of 200 patients started on clozapine during the period of January 2006-June 2014 were reviewed. The mean delay in clozapine initiation was 1.93 (S.D. 1.82) years and median was 1.5 years. Mean of 3 (S.D. 1.18) adequate antipsychotic trials was given prior to considering clozapine and 27.5% patients had received polypharmacy prior to clozapine. Factors related to delay in starting of clozapine included higher age, longer duration of illness, age more than 20 years of age, polypharmacy, use of an adequate trial of typical antipsychotic medication, patients from urban locality and those with onset of illness prior to introduction of clozapine into Indian market. Findings of the present study suggest that there is a delay of 1.5-2 years in starting of clozapine and about one-fourth of patients receive polypharmacy prior to receiving clozapine. These finding suggests that there is a need to change the prescribing habits to reduce the delay in starting of clozapine.