Attitude towards and experience with clozapine of patients and their caregivers after three months of starting of clozapine

Patient and caregivers perspective about clozapine: A systematic review

BACKGROUND

Clozapine is a gold standard treatment for treatment-resistant schizophrenia. However, the patients' and caregivers' perception and their experience with clozapine has remained much less explored.

AIM

To review the available literature on the patients' and caregivers' attitudes, perceptions, and experiences with clozapine.

METHODOLOGY

27 original research and review articles published in PubMed-indexed journals till March 2023 in the English language, exploring the patient and/or caregiver/family member's experience with using clozapine, were included.

RESULTS

30-80 %of patients and 92-100 % of caregivers were found to have a positive attitude towards clozapine in terms of its impact on psychopathology, cognitive and social functioning of the patient, and caregiving needs. Most patients and caregivers also found that the positive effects of clozapine outweighed the side effects and distress related to repeated blood testing. However, a lack of satisfaction was noted among both patients and caregivers regarding the knowledge provided to them regarding clozapine, especially regarding its common adverse effects. Discontinuation of clozapine was found to be more commonly done by the patients' accord rather than clinicians, and the perceived side effects like hypersalivation and excessive sedation emerge as important factors that lead to discontinuation rather than the need for repeated blood testing.

CONCLUSIONS

Overall, patients and their caregivers share a positive attitude towards clozapine and perceive it to be an effective and beneficial drug, but more effort needs to be directed by the clinical teams to educate the users of clozapine regarding its complete side effect profile and provide continuous guidance about dealing with the emerging side effects throughout treatment.

Clozapine Efficacy and Adverse Drug Reactions Among a Nationwide Study of 1021 Australians Prescribed Clozapine: The ClozaGene Study

BACKGROUND AND HYPOTHESIS

The ClozaGene Study is a nationwide cohort of adults who have been treated with clozapine. While clozapine is indicated in the management of treatment-resistant schizophrenia, it is associated with a considerable adverse drug reaction (ADR) burden, and not all patients achieve adequate symptomatic response. The current study focuses on self-reported experiences of clozapine use and response, clozapine-associated ADRs, and mental health comorbidity.

STUDY DESIGN

A total of 1021 participants (41.0% female; aged 46.2 ± 10.6 years [range 18-66]) were recruited via a mail-out based on prescriptions for clozapine. Participants completed a self-report questionnaire.

STUDY RESULTS

Most participants (90.1%, n = 912) were living with schizophrenia while 41.5% reported a lifetime diagnosis of depression, 15.6% bipolar disorder, and 8.1% schizoaffective disorder. Clozapine was currently prescribed to 944 (92.5%) participants and 37.8% of these participants self-reported currently taking additional antipsychotic medication. Nearly 3 quarters of participants living with schizophrenia reported that clozapine helped control their schizophrenia symptoms moderately to very well. The most commonly reported ADRs were sialorrhea (80.3%), weight gain (71.0%), constipation (56.9%), and sedation (52.8%). The prevalence of clozapine cessation due to clozapine-induced myocarditis and neutropenia was 1% and 0.4%, respectively.

CONCLUSIONS

Our findings highlight the high rate of psychotic and metabolic symptoms and ADRs among adults prescribed clozapine in the general Australian population. Future genomic analyses will focus on identifying genetic variants influencing clozapine treatment response and side effects.

Experience with and attitude toward clozapine use among patients receiving clozapine on long term and their caregivers

Background

Despite clozapine being the gold standard for treating patients suffering from treatment-resistant schizophrenia, the experience and attitude of patients receiving clozapine for a long duration and their caregivers have not been evaluated, especially in India and other low-middle-income countries. Also, no standardized scale has been validated for such assessment.

Objective

This study aimed to evaluate the perception regarding clozapine among patients and their caregivers. We also attempted to evaluate the factor structure of the scale for such assessment.

Methods

A total of 172 consenting patients who have been receiving clozapine for ≥1 year and their caregivers were evaluated on self-designed questionnaires (patient and caregiver versions containing 44 and 47 items, respectively) to assess various aspects of their experiences about clozapine use.

Results

A majority (70-80%) of patients and caregivers reported improvement in psychotic symptoms, mood symptoms, and overall functioning with starting of clozapine. However, about 40% of the patients reported cognitive side effects, and 20-25% reported disabling side effects like lethargy, forgetfulness and decreased attention, and distress related to blood testing after starting of clozapine. Factor analysis of the questionnaires yielded five- and seven-factor models for the experience and attitude of the patients and the caregivers, respectively. The positive experiences were associated clinical and functional improvement, lower disability, and improvement in functioning as well as the self-reported perceived improvement by the patient and caregiver.

Conclusion

This study suggests that patients tend to have an overall positive experience and attitude about using clozapine. The caregivers also report the beneficial effect on the caregiving. A good level of agreement was seen between the experience of patients, caregivers, and clinician-rated improvement in the psychopathology and functioning.

Patients' and primary carers' views on clozapine treatment for schizophrenia: A cross-sectional study in Qatar

Subjective views of clozapine treatment among patients with schizophrenia in the Middle East and North African MENA Region have not previously been assessed. Globally, few studies have assessed the views of carers to clozapine treatment. We conducted a cross-sectional survey, using a clinician administered structured interview, of patients with schizophrenia/schizoaffective disorder prescribed clozapine in Qatar, and their primary carers. Participants were asked to rate clozapine against prior their antipsychotic treatment in terms of specific benefits and side effects. Forty-two patients and 33 carers participated in the study. Of the patients, two thirds were male, approximately half were Qatari and the mean age was 33.9 years. Patients and carers rated clozapine as superior to prior antipsychotic treatment on all 7 potential benefits inquired about. The greatest perceived benefit was improved mood. Patients rated clozapine as less likely to cause extrapyramidal side effects but more likely to cause 18 other potential side effects compared to prior antipsychotic treatment, with the greatest difference being for nocturnal salivation, increased appetite, and constipation. Nearly half of patients (48 %) and two thirds of carers (64 %) stated that they would have preferred to start clozapine earlier in their illness. Sixty percent of patients and 37 % of carers regarded the information that they had received from health professionals on clozapine as inadequate. Less than half of patients and approximately-two thirds of carers had adequate knowledge of haematological monitoring for clozapine. Generally, there were significantly positive correlation between patients and carers regarding the overall side effects of clozapine treatment. Likewise, improvement in hearing voices paranoid thoughts correlated with improved quality of life. In summary, the results show that patients and carers appreciate the benefits of clozapine despite its side effects being problematic. The results support clozapine being offered earlier in treatment and services providing more information on clozapine to patients and carers.

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.

Patients' Experiences of Clozapine for Treatment-Resistant Schizophrenia: A Systematic Review

Background

Clozapine is the most effective antipsychotic for patients with treatment-resistant schizophrenia (TRS), however, it remains widely under-utilized in clinical practice. To date, relatively little attention has been given to patients' experience of clozapine. By synthesizing the existing literature, we sought to determine the experiences of patients with TRS treated with clozapine.

Methods

A systematic review was conducted on Embase, Medline, PsychInfo, and PubMed databases for studies from 1956 to 2021. English language studies and those based on adult patients prescribed clozapine for TRS were included.

Results

Thirteen studies were included with a total of 1487 patients and a narrative synthesis was performed. Overall, most patients reported positive experiences of clozapine, with generally high levels of satisfaction, alongside symptom improvement and preference over previous medications. Negative experiences of clozapine were less common, but when mentioned, focused on blood tests and common side effects, including hypersalivation and weight gain.

Conclusions

This is the first systematic review exploring patients' subjective experiences of clozapine for TRS. Findings suggest that patients generally have a favorable experience when being treated with clozapine. However, conclusions are limited by the risk of bias, particularly survivorship bias. High-quality longitudinal studies exploring patients' experiences of clozapine are indicated for the future.

Cluster Analysis of Clozapine Consumer Perspectives and Comparison to Consumers on Other Antipsychotics

Despite its unique efficacy, clozapine remains underutilized in the United States. Perceptions about clozapine and barriers to its use have been examined among prescribers, but insufficiently studied among consumers. We surveyed 211 antipsychotic consumers (86 on clozapine and 125 on other antipsychotics) on their medication-related perspectives in a public hospital system in Atlanta, Georgia, USA. In contrast to their previous regimen, 72% of clozapine consumers reported they were more satisfied with clozapine. When compared with consumers taking other antipsychotics, clozapine consumers reported more side effects but did not differ on other measures of satisfaction or efficacy. We found Caucasians to be overrepresented among clozapine, as compared to other antipsychotic consumers. Side effects most strongly associated with poor safety ratings were sedation, limb jerking, and dizziness when standing. However, clozapine was only rated less safe by consumers who experienced more than one of these side effects. We used an unsupervised clustering approach to identify three major groups of clozapine consumers. Cluster A (19%) had the lowest safety ratings, aversion to blood work, and a high rate of side effects that associate with lower safety ratings. Cluster B (25%) experienced more hospitalizations and reported satisfaction with clozapine that correlated with efficacy ratings, irrespective of safety ratings. Cluster C (56%) experienced fewer hospitalizations, fewer previous drug trials, greater educational attainment, lower rates of smoking, and rated clozapine more highly. This work identifies common side effects that influence the subjective safety of clozapine and suggests that attitudes toward clozapine depend on context-specific factors.

Nose to brain delivery of tailored clozapine nanosuspension stabilized using (+)-alpha-tocopherol polyethylene glycol 1000 succinate: Optimization and in vivo pharmacokinetic studies

Clozapine is widely used to treat schizophrenia as an atypical antipsychotic. Low solubility, poor dissolution rate, degradation in the gastrointestinal tract, high hepatic first-pass metabolism, and eventually less drug transfer in the brain are all issues with oral clozapine administration. On account of this poor pharmacokinetic parameters, the authors aimed to develop clozapine nanosuspension using (+)-alpha-tocopherol polyethylene glycol 1000 succinate (TPGS) and polyvinylpyrrolidone K-30 (PVP K-30) and deliver it through the intranasal route. The nanosuspension was prepared by the high-speed homogenization method with 3² full factorial design for optimization of the product. Quality Target Product Profile (QTPP) was enlisted before the product development. The amount of TPGS and speed of homogenizer were selected as independent variables whereas, particle size and drug permeation profile after 24 h (Y₂, %) were selected as dependent variables. As per the results of optimization, amount of TPGS and speed of homogenizer were chosen as 0.1% and 7000 rpm, respectively. The particle size of the optimized nanosuspension of clozapine was found to be 281 nm. The conversion of clozapine crystals to an amorphous form was verified by characterization studies (XRD and DSC). The drug permeability study showed 96.15% and 41.12% clozapine release after 24 h from nanosuspension and conventional suspension, respectively. The study of nasal cilio-toxicity (histopathological studies) demonstrated the appropriateness of nanosuspension for intranasal purposes. The single-dose in vivo pharmacokinetic analysis in the rat model showed a substantial increase in the therapeutic concentration of clozapine in the brain tissue in the case of intranasal nanosuspension (dose = 0.05 mg drug/0.1 mL, C_max = 8.62 ± 0.45 μg/g, t_max = 1 h) compared to conventional oral clozapine suspension (dose = 26.43 mg drug/0.158 mL, C_max = 1.14 ± 0.12 μg/g, t_max = 1 h).Ultimately, in the case of an intranasal route, a 3.56-fold increase in brain drug concentration was observed with a 528-fold lower drug dose compared with oral administration. The results suggest that clozapine nanosuspension may be used for successful nose-to-brain delivery.