Early treatment resistance in a Latin-American cohort of patients with schizophrenia

Bioanalytical LC-QTOF/MS Method for a N-phenylpiperazine Derivate (LQFM05): An Anxiolytic- and Antidepressant-like Prototype Drug Applied to Pharmacokinetic and Biodistribution Studies

The LQFM05 is a prototype drug designed for treatment of psychiatric disorders, such as schizophrenia, exhibiting anxiolytic- and antidepressant-like (12 or 24 µmol/kg) effects in classical behavioral tests. In order to evaluate its pharmacokinetic properties, a liquid chromatography method coupled to a quadrupole time of flight mass spectrometry system (LC-QTOF/MS) was developed and fully validated for LQFM05 analysis in rat plasma and tissue samples (brain, heart, liver, and kidneys). Liquid-liquid extraction, solid phase extraction and protein precipitation were assessed as clean-up procedures for biological samples and analyte enrichment. Plasma and tissue samples underwent protein precipitation as a preliminary step, using acetonitrile. Linearity was fully demonstrated for the dynamic range (10.0 to 900.0 ng/mL), with r² values higher than 0.99 (RSD_slope ≤ 2%, F_cal < F_tab, C_cal < C_tab). Biodistribution studies in rats revealed high brain tissue concentrations (12.4 µg/g), suggesting elevated drug affinity to the main therapeutic target tissue, showing a blood partition coefficient of 1.9. Kidneys also showed great exposure and tissue affinity, suggesting a potential extrahepatic clearance. Likewise, all examined tissues exhibited satisfactory LQFMF05 distribution. The mass fragmentation spectrum indicated the presence of its main metabolite, LQFM235, yielded by high hepatic hydroxylation route, an equally bioactive derivative. Lastly, the developed LC-QTOF/MS method was shown to be sensitive (LOQ = 10 ng/mL), precise and accurate for LQFM05 determination in tissue homogenates and plasma samples.

Consent, decisional capacity and guardianship in mental health research

Background: Research with adults who cannot give informed consent has important social value. However, enrolling adults who cannot consent in research raises significant ethical concerns.  Methods: To evaluate how researchers in low and middle-income countries (LMICs) can assess individuals' decisional capacity, and the conditions under which it is appropriate, and the conditions under which it is not appropriate to include individuals who lack decisional capacity.  Results: In LMICs, where resources may be limited, implementing protections for adults with decisional incapacity can be especially challenging. Recognition of the ethical concerns, and awareness of the circumstances and available resources, offers the means to protect these vulnerable participants. Conclusions: Researchers in low and middle-income countries should be aware of steps they can take to ensure appropriate protections for subjects with decisional impairments while conducting clinical trials on methods to improve their clinical care.

Consent, decisional capacity and guardianship in mental health research

Background: Research with adults who cannot give informed consent has important social value. However, enrolling adults who cannot consent in research raises significant ethical concerns.  Methods: To evaluate how researchers in low and middle-income countries (LMICs) can assess individuals’ decisional capacity, and the conditions under which it is appropriate to include and the conditions under which it is appropriate to exclude individuals who lack decisional capacity.  Results: In LMICs, where resources may be limited, implementing protections for adults with decisional incapacity can be especially challenging. Recognition of the ethical concerns, and awareness of the circumstances and available resources, offers the means to protect these vulnerable participants. Conclusions: Researchers in low and middle-income countries should be aware of steps they can take to ensure appropriate protections for subjects with decisional impairments while conducting clinical trials on methods to improve their clinical care.

Treatment-resistant schizophrenia: Addressing white matter integrity, intracortical glutamate levels, clinical and cognitive profiles between early- and adult-onset patients

BACKGROUND

Treatment-resistance in schizophrenia is 30-40%. Its neurobiology remains unclear; to explore it, we conducted a combined spectrometry/tractography/cognitive battery and psychopathological rating study on patients with treatment-resistant schizophrenia (TRS), dividing the sample into early-onset (N = 21) and adult-onset TRS (N = 20). Previous studies did not differentiate between early- (onset 13-18 years) and adult-onset (>18 years at formal diagnosis of schizophrenia) TRS.

METHODS

We evaluated cross-sectionally 41 TRS patients (26 male and 15 female) and 20 matched healthy controls (HCs) with psychopathological and cognitive testing prior to participating in brain imaging scanning using magnetic resonance spectroscopy and diffusion tensor imaging to determine the relationship between their symptoms and their glutamate levels and white matter integrity.

RESULTS

TRS patients scored lower than HCs on all cognitive domains; early-onset patients performed better than adult-onset patients only on the Symbol Coding domain. TRS correlated with symptom severity, especially negative symptoms. Glutamate levels and glutamate/creatine were increased in anterior cingulate cortex. Diffusion tensor imaging showed low fractional anisotropy in TRS patients in specific white matter tracts compared to HCs (bilateral anterior thalamic radiation, cortico-spinal tract, forceps minor, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus, and right uncinate fasciculus).

CONCLUSIONS

We identified specific magnetic resonance spectroscopy and diffusion tensor imaging alterations in TRS patients. Adult-onset TRS differed little from early-onset TRS on most measures; this points to alterations being present since the outset of schizophrenia and may constitute a biological signature of treatment-resistance.

Clozapine induces metformin-resistant prediabetes/diabetes that is associated with poor clinical efficacy in patients with early treatment-resistant schizophrenia

BACKGROUND

Two distinct subtypes of treatment-resistant schizophrenia (TRS) have been recently reported, including early-treatment resistance (E-TR) and late-treatment resistance (L-TR). This study was to assess clozapine-induced metformin-resistant prediabetes/diabetes and its correlation with clinical efficacy in schizophrenia E-TR subtype.

METHODS

This prospective cohort study enrolled 230 patients with schizophrenia E-TR subtype and they were treated with adequate doses of clozapine for 16 weeks, during which patients with prediabetes/diabetes were assigned to receive add-on metformin. The main outcomes and measures included incidence of clozapine-induced prediabetes/diabetes and metformin-resistant prediabetes/diabetes, and the efficacy of clozapine as assessed by the Positive and Negative Syndrome Scale (PANSS) score.

RESULTS

Clozapine-induced prediabetes/diabetes occurred in 76.52% of patients (170 prediabetes and 6 diabetes), of which the blood sugar of 43 (24.43%) patients was controlled with metformin. Despite add-on metformin, 47.06% (74/170) of prediabetes patients progressed to diabetes. In total, the incidence of clozapine-induced metformin-resistant prediabetes/diabetes was 75.57% (133/176). On completion of 16-week clozapine treatment, 16.52% (38/230) patients showed clinical improvement with PANSS scores of ≥50% declining. Furthermore, clozapine-induced prediabetes/diabetes was significantly correlated with the poor clinical efficacy of clozapine for schizophrenia E-TR subtype.

CONCLUSIONS

The incidence of clozapine-induced metformin-resistant prediabetes/diabetes was considerably high in the schizophrenia E-TR subtype. Clozapine-induced metformin-resistant prediabetes/diabetes represents an independent risk factor that adversely affects the clinical efficacy of clozapine for the schizophrenia E-TR subtype. This study provided new evidence for re-evaluating the use of clozapine for TRS, especially E-TR subtype, and the use of metformin for the glycemic control of clozapine-induced prediabetes/diabetes.

Predictors of clozapine discontinuation at 2 years in treatment-resistant schizophrenia

INTRODUCTION

Little is known about predictors of clinical response to clozapine treatment in treatment-resistant psychosis. Most published cohorts are small, providing inconsistent results. We aimed to identify baseline clinical predictors of future clinical response in patients who initiate clozapine treatment, mainly focusing on the effect of age, duration of illness, baseline clinical symptoms and homelessness.

METHODOLOGY

Retrospective cohort of patients with treatment-resistant schizophrenia, aged between 15 and 60 years, that initiated clozapine between 2014 and 2017. Sociodemographic characteristics, years from illness diagnosis, and clinical presentation before the initiation of clozapine were collected and analyzed. All-cause discontinuation at two years follow-up was used as the primary measure of clozapine response.

RESULTS

261 patients were included with a median age at illness diagnosis of 23 years old (IQR 19-29) and a median age at clozapine initiation of 25 (IQR: 21-33). 72.33% (183/253) continued clozapine after two years follow-up. Being homeless was associated to higher clozapine non-adherence, with an OR of 2.78 (95%CI 1.051-7.38) (p = 0.039, controlled by gender). Older age at clozapine initiation and longer delay from first schizophrenia diagnosis to clozapine initiation were also associated with higher clozapine non-adherence, with each year increasing the odds of discontinuation by 1.043 (95%CI 1.02-1.07; p = 0.001) and OR 1.092 (95%CI 1.01-1.18;p = 0.032) respectively.

CONCLUSION

Starting clozapine in younger patients or shortly after schizophrenia diagnosis were associated with better adherence.

High prevalence of metabolic alterations in Latin American patients at initial stages of psychosis

AIM

Studies conducted in the United States have highlighted a higher prevalence of metabolic alterations (MA) in Latino population and Latino psychotic patients. Metabolic risk in psychosis is known to be present from initial stages of the disease. To better characterize this population, we explored the prevalence of MA and metabolic syndrome (MS) in early psychosis patients in a Latin American country.

METHODS

Transversal, observational study comparing the prevalence of MA and MS in patients with early psychosis from an outpatient program in Chile (n = 148) with a community representative sample from the 2009-2010 National Health Survey (n = 568). ANOVA and regression analysis were performed obtaining odds ratio for MA and MS.

RESULTS

The prevalence of MS was 44.7% in patients compared to 11.4% in the community sample (odds ratio [OR] 5.28, confidence interval [CI] 95% 3.07-9.08; P-value <0.001). There was no effect of gender. Subgroup analyses showed no significant association of MS with clozapine/olanzapine use, treatment duration or tobacco use. There was an association between treatment duration and hypertriglyceridemia (P = 0.024; OR 1.02, CI 95% 1.00-1.04) and obesity (P = 0.007; OR 5.93, CI 95% 1.82-20.22). Clozapine/olanzapine use was associated with hyperglycaemia (P = 0.007; OR 6.04, CI 95% 1.63-22.38) and high low density lipoprotein (P = 0.033 ANOVA; OR 5.28, CI 95% 1.14-24.37).

CONCLUSION

Latino psychotic patients have a high risk of MA and MS at initial stages of the disease which is not entirely explained by the higher risk in the whole Latino population, is irrespective of gender, and does not seem to be entirely a response to atypical antipsychotic use.

Clozapine-associated neutropenia in Latin America: incidence report of 5380 Chilean users

Systematic information about Latino clozapine users is still scarce. Our aim was to evaluate the risk of clozapine-associated neutropenia in a Chilean cohort using the last Food and Drug Administration's recommendations for clozapine monitoring. Findings should improve clinical practice and promote changes in clozapine guidelines in Latin America. We conducted a retrospective observational study of 5380 Chilean clozapine users that started clozapine treatment between 2003 and 2015. The absolute risk of severe neutropenia was 0.61% (33/5380) with an incidence of 0.086 cases per 100 person-years of follow-up. 87.9% of cases with severe neutropenia appeared during first 18 weeks. Cases of mild neutropenia were 3.9% of total sample and occurred almost constantly without a specific risk time. 77.5% of cases of moderate or severe neutropenia didn't present an event of mild neutropenia before. 22.8% of clozapine users (1227/5380) discontinued treatment for any cause and 4.2% (225/5380) due to neutropenia in any severity level. Clozapine-associated neutropenia risk in Latino users is similar than in the rest of the world. The evidence of a very low risk for severe neutropenia and the behaviour of mild neutropenia cases confirm the feasibility of changes in Latin American clozapine guidelines using current Food and Drug Administration's recommendations as a model.

Association of smoked cannabis with treatment resistance in schizophrenia

Association of cannabis use with schizophrenia is a well-established finding. Its role in causation, however, is debated. Different studies have found that cannabis use impacts the outcome of schizophrenia and is associated with treatment non-adherence and a higher rate of relapses. In this paper, we investigated the impact of self-reported cannabis use on treatment response in a cohort of schizophrenia patients from Pakistan, a middle-income country. The data was collected from a psychiatric hospital in Khyber Pakhtunkhwa province of Pakistan where cannabis use is prevalent. Clinical evaluation and therapeutic response were established using the Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impressions Scales-Severity (CGI-S) and Improvement (CGI-I) scale. Lack of response to adequate treatment with two trials of antipsychotics was classed as treatment resistance. We compared the treatment-resistant and treatment responsive groups for different variables including cannabis use, age at onset of illness, duration of untreated psychosis and consanguinity. We had data on 230 patients. More than ninety percent of our participants were men. The rate of treatment resistance was over 60%. Ongoing use of cannabis had an association with treatment resistance. We only included cases where treatment adherence was not a problem.

Does relapse contribute to treatment resistance? Antipsychotic response in first- vs. second-episode schizophrenia

Although some studies have suggested that relapse may be associated with antipsychotic treatment resistance in schizophrenia, the number and quality of studies is limited. The current analysis included patients with a diagnosis of first-episode schizophrenia or schizoaffective disorder who met the following criteria: (1) referral to the First-Episode Psychosis Program between 2003 and 2013; (2) treatment with an oral second-generation antipsychotic according to a standardized treatment algorithm; (3) positive symptom remission; (4) subsequent relapse (i.e., second episode) in association with non-adherence; and (5) reintroduction of antipsychotic treatment with the same agent used to achieve response in the first episode. The following outcomes were used as an index of antipsychotic treatment response: changes in the brief psychiatric rating scale (BPRS) total and positive symptom scores and number of patients who achieved positive symptom remission and 20 and 50% response. A total of 130 patients were included in the analyses. Although all patients took the same antipsychotic in both episodes, there were significant episode-by-time interactions for all outcomes of antipsychotic treatment response over 1 year in favor of the first episode compared to the second episode (50% response rate: 48.7 vs. 10.4% at week 7; 88.2 vs. 27.8% at week 27, respectively). Although antipsychotic doses in the second episode were significantly higher than those in the first episode, results remained unchanged after adjusting for antipsychotic dose. The present findings suggest that antipsychotic treatment response is reduced or delayed in the face of relapse following effective treatment of the first episode of schizophrenia.