Weeks Of Clozapine Treatment Research Articles

Risk of clozapine-associated agranulocytosis and mandatory white blood cell monitoring: Can the regulations be relaxed?

After the introduction of clozapine eight Finnish patients died after developing agranulocytosis. Clozapine was withdrawn from the market and only reintroduced with strict mandatory white blood cell monitoring as long as treatment lasts and thresholds at which clozapine must be discontinued definitively. The fear of agranulocytosis and the need for intensive blood monitoring is the single most important barrier for prescribers and patients alike and leads to underprescription of the only effective and approved medication for treatment-resistant schizophrenia. We summarize evidence that the risk of agranulocytosis is smaller than perceived at the time of reintroduction, is concentrated in the first 18 weeks of treatment, is not greater than with other antipsychotics thereafter and that frequent blood monitoring has not demonstrably decreased the rate of agranulocytosis. Therefore we propose 1) mandatory monitoring of the absolute neutrophil count (ANC) exclusively during the first 18 weeks of clozapine treatment, 2) that thereafter the prescriber and the well-informed patient decide together about further monitoring frequency, 3) that clozapine treatment must be stopped if the ANC falls below 1.0 × 109/L. Continuation of clozapine or a rechallenge are possible if prescriber and patient determine that the benefits outweigh the risks. 4) National registries which control the haematologic monitoring are unnecessary and do not help to reduce clozapine-induced agranulocytosis. They should at least be restricted to the first 18 weeks of clozapine use.

Early neutrophil trajectory following clozapine may predict clozapine response – Results from an observational study using electronic health records

BackgroundClozapine has unique effectiveness in treatment-resistant schizophrenia and is known to cause immunological side-effects. A transient spike in neutrophils commonly occurs in the first weeks of clozapine therapy. There is contradictory evidence in the literature as to whether neutrophil changes with clozapine are linked to treatment response. AimsThe current study aims to further examine the neutrophil changes in response to clozapine and explore any association between neutrophil trajectory and treatment response. MethodsA retrospective cohort study of patients undergoing their first treatment with clozapine and continuing for at least 2 years identified 425 patients (69% male/31% female). Neutrophil counts at baseline, 3 weeks and 1 month were obtained predominantly by linkage with data from the clozapine monitoring service. Clinical Global Impression- Severity (CGI-S) was rated from case notes at the time of clozapine initiation and at 2 years. Latent class growth analysis (LCGA) was performed to define distinct trajectories of neutrophil changes during the first month of treatment. Logistic regression was then conducted to investigate for association between the trajectory of neutrophil count changes in month 1 and clinical response at 2 years as well as between baseline neutrophil count and response. ResultsOf the original cohort, 397 (93%) patients had useable neutrophil data during the first 6 weeks of clozapine treatment. LCGA revealed significant differences in neutrophil trajectories with a three-class model being the most parsimonious. The classes had similar trajectory profiles but differed primarily on overall neutrophil count: with low, high-normal and high neutrophil classes, comprising 52%, 40% and 8% of the sample respectively. Membership of the high-normal group was associated with significantly increased odds of a positive response to clozapine, as compared to the low neutrophil group [Odds ratio (OR) = 2.10, p-value = 0.002; 95% confidence interval (95% CI) = 1.31–3.36]. Baseline neutrophil count was a predictor of response to clozapine at 2 years, with counts of ≥5 × 109/l significantly associated with positive response (OR = 1.60, p-value = 0.03; 95% CI = 1.03–2.49). ConclusionsOur data are consistent with the hypothesis that patients with low-level inflammation, reflected in a high-normal neutrophil count, are more likely to respond to clozapine, raising the possibility that clozapine exerts its superior efficacy via immune mechanisms.

Changes in corticostriatal connectivity and striatal tissue iron associated with efficacy of clozapine for treatment‑resistantschizophrenia.

RationaleThough numerous studies demonstrate the superiority of clozapine (CLZ) for treatment of persistent psychotic symptoms that are characteristic of treatment-refractory schizophrenia (TRS), what remains unknown are the neural and molecular mechanisms underlying CLZ’s efficacy. Recent work implicates increased corticostriatal functional connectivity as a marker of response to non-CLZ, dopamine (DA) D2-receptor blocking antipsychotic drugs. However, it is undetermined whether this connectivity finding also relates to CLZ’s unique efficacy, or if response to CLZ is associated with changes in striatal DA functioning.ObjectiveIn a cohort of 22 individuals with TRS, we examined response to CLZ in relation to the following: (1) change in corticostriatal functional connectivity; and (2) change in a magnetic resonance-based measure of striatal tissue iron (R2’), which demonstrates utility as a proxy measure for elements of DA functioning.MethodsParticipants underwent scanning while starting CLZ and after 12 weeks of CLZ treatment. We used both cortical and striatal regions of interest to examine changes in corticostriatal interactions and striatal R2’ in relation to CLZ response (% reduction of psychotic symptoms).ResultsWe first found that response to CLZ was associated with an increase in corticostriatal connectivity between the dorsal caudate and regions of the frontoparietal network (P < 0.05, corrected). Secondly, we observed no significant changes in striatal R2’ across CLZ treatment.ConclusionOverall, these results indicate that changes in corticostriatal networks without gross shifts in striatal DA functioning underlies CLZ response. Our results provide novel mechanistic insight into response to CLZ treatment.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00213-022-06138-0.

Relationship between plasma clozapine/N-desmethylclozapine and changes in basal forebrain-dorsolateral prefrontal cortex coupling in treatment-resistant schizophrenia

Clozapine (CLZ) demonstrates a unique clinical efficacy relative to other antipsychotic drugs. Previous work has linked the plasma ratio of CLZ and its major metabolite, N-desmethylclozapine (NDMC), to an inverse relationship with cognition via putative action on the cholinergic system. However, neuroimaging correlates of CLZ/NDMC remain unknown. Here, we examined changes in basal forebrain functional connectivity with the dorsolateral prefrontal cortex, and secondly, cognition in relation to the CLZ/NDMC ratio. A cohort of nineteen chronically ill participants with treatment-resistant schizophrenia (TRS) undergoing 12 weeks of CLZ treatment were included. Measures of cognition and plasma CLZ/NDMC ratios were obtained in addition to resting-state functional neuroimaging scans, captured at baseline and after 12 weeks of CLZ treatment. We observed a significant correlation between basal forebrain-DLPFC connectivity and CLZ/NDMC ratios across CLZ treatment (p = 0.02). Consistent with previous findings, we also demonstrate a positive relationship between CLZ/NDMC ratio and working memory (p = 0.03). These findings may reflect the action of CLZ and NDMC on the muscarinic cholinergic system, highlighting a possible neural correlate of cognition across treatment.

T19. GLUTAMATE AND RESPONSE TO CLOZAPINE IN TREATMENT RESISTANT SCHIZOPHRENIA

BackgroundThe mechanisms that underlie and may mediate the therapeutic response to clozapine in treatment resistant schizophrenia (TRS) are unclear. Basic science studies have indicated that clozapine may modulate brain glutamate, but this has not yet been investigated in man. The aim of this study was to determine whether clozapine alters brain glutamate levels in patients with TRS, and the associations with clinical outcome.MethodsThe study included patients with TRS who were about to start clozapine as part of their normal clinical care. Glutamate levels were measured in the anterior cingulate cortex (ACC) and right caudate nucleus using proton magnetic resonance spectroscopy (1H-MRS) before clozapine initiation (n=37) and again after 12-weeks of clozapine treatment (n=27). Symptoms were principally assessed using the PANSS. 1H-MRS scans were also acquired in a comparator group of healthy volunteers (n = 16).ResultsOver the 12 weeks of clozapine treatment there was a significant reduction in glutamate in the caudate (n = 22, F = 7.61 P < 0.05) but not in the ACC. The percentage reduction in caudate glutamate was positively associated with the percentage reduction in total PANSS score (n = 23, r = 0.42, P = 0.04). ACC Glx (glutamate plus glutamine) prior to clozapine initiation was higher in patients with TRS than in healthy volunteers (P=0.03).DiscussionImprovements in symptoms following clozapine initiation in TRS may be related to reductions in glutamate in the caudate nucleus. In contrast, ACC glutamate levels appear to remain high during the first three months of clozapine treatment.

M215. FACTORS ASSOCIATED WITH CLOZAPINE RESPONSE AND RESISTANCE IN SCHIZOPHRENIA

BackgroundClozapine remains the only antipsychotic with unique efficacy in treatment resistant schizophrenia (TRS). Considerable ongoing research and clinical efforts have focused on reducing barriers to clozapine use in a bid to increase rates of clozapine use to improve outcomes in TRS. However, less than half of individuals with TRS respond to clozapine, with the remainder categorised as clozapine resistant (CRS) or Ultra-resistant. It is important to deepen understanding on the development of CRS so we can identify them early, attempt to prevent/delay its onset and also explore novel treatments. In the present study, we sought to compare clozapine responders from CRS and identify factors which might be associated with CRS.MethodsThis study was conducted at the Institute of Mental Health, the only psychiatric facility with clozapine services in Singapore. Individuals with TRS on clozapine for at least 12 weeks and the capacity to give informed consent were enrolled into the study. Each participant underwent a clinical assessment on the Structured Clinical Interview DSM-IV-TR (SCID), Positive and Negative Syndrome Scale (PANSS) and Social Occupational Functioning Assessment Scale (SOFAS). We applied the Treatment Response and Resistance In Psychosis consensus criteria to define clozapine response and resistance. Brief Neurocognitive Assessment was done using the digit sequencing and symbol coding tasks from the Brief Assessment of Cognition in Schizophrenia (BACS). A fasting sample of blood was collected; assays for clozapine and norclozapine were performed using high performance liquid chromatography. To be classified as CRS, a participant must meet the below criteria: (i) not meeting symptom remission criteria on the PANSS using the Remission in Schizophrenia Working Group criteria, (ii) moderate and lower level of functioning on the SOFAS, and (iii) at least 12 weeks of clozapine treatment and plasma clozapine levels ≥ 350 ng/ml.ResultsA total of 91 participants were enrolled in this study and 67 (73.6%) met criteria for CRS. 1 in 4 clozapine responders had plasma clozapine levels not exceeding 350 ng/ml. There were no significant differences in age, sex, smoking status, age at onset of illness, clozapine adherence, antipsychotic polypharmacy rates and duration of clozapine use between clozapine responders and CRS. Compared to clozapine responders, individuals with CRS had statistically significantly lower BMI (26.4 vs. 23.4, p=0.008) lower rates of employment (79.2% vs. 35.8%, p<0.001), and poorer cognitive function in both digit sequencing (-0.86 vs. -1.60, p=0.011) and symbol coding (-1.09 vs. -1.88, p=0.002) tasks. In a multivariate logistic regression model with age, sex, age at onset, BMI and cognition, only BMI (OR=0.88, p=0.043) and symbol coding (OR=0.48, p=0.019) were significant variables predicting clozapine resistance.DiscussionOur study highlighted a high rate of CRS and suggests that poorer cognitive function, specifically in processing speed, might be associated with the development of clozapine resistance in schizophrenia. Additionally, it was interesting to note that a higher BMI was associated with clozapine response; this lends weight to existing metabolic and lipid hypotheses of schizophrenia.

Effect of Clozapine on Proton Magnetic Resonance Spectroscopy Findings in Hippocampus.

The purpose of this study was to investigate the effect of clozapine on proton magnetic resonance spectroscopy (1H-MRS) findings in hippocampus in patients with schizophrenia. In addition, the relationship between the change in 1H-MRS findings and the change in psychopathology and neurocognitive functions was evaluated. Patients with schizophrenia (n=16) were assessed with the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Scale (CGI), a neurocognitive test battery and 1H-MRS at baseline, and twelve weeks after the initiation of clozapine. Healthy controls (n=8) were assessed once with a neurocognitive test battery and 1H-MRS. Bilateral multivoxel and left single voxel NAA/Cr, Cho/Cr, MI/Cr was calculated in the hippocampi. After 12 weeks of clozapine treatment, PANSS and CGI scores decreased; immediate recall, cumulative learning subtests of the Rey Auditory Verbal Learning Test, Category Verbal Fluency Test and Wechsler Memory Scale's visual reproduction delayed subtest scores increased significantly. Compared with healthy controls and patients after clozapine, hippocampi multivoxel and single voxel NAA/Cr, Cho/ Cr, MI/Cr ratios were not different in patients before clozapine. No significant correlations between change in 1H-MRS metabolite ratios and change in psychopathology, neurocognitive functions were detected. This study is the first longitudinal study to investigate the effect of clozapine in hippocampus with 1H-MRS. There were no significant changes in 1H-MRS findings in hippocampi after twelve weeks of clozapine treatment. Clozapine's effect in hippocampus should be investigated further in longer follow up studies with larger samples to reach a final conclusion.

The physical health and side-effect monitoring of patients prescribed clozapine: data from a clinical audit conducted in UK mental health services.

Background:In addition to mandatory haematological monitoring, treatment guidelines recommend routine monitoring of adverse effects and physical health in patients prescribed clozapine.Methods:NHS trusts/healthcare organisations participated in a clinical audit in the context of a UK quality improvement programme addressing clozapine-prescribing practice.Results:Data relating to 6948 adult patients prescribed clozapine were submitted by 63 NHS trusts/healthcare organisations. Of 481 patients treated with clozapine for up to 18 weeks, there was documented pretreatment screening of blood pressure, heart rate and ECG in at least 90%, and body weight, plasma lipids, plasma glucose/glycated haemoglobin (HbA1c) and physical examination in approximately 80%. During the first 2 weeks of clozapine treatment there was documented daily measurement of both heart rate and blood pressure in 82% and body temperature in 77%. In a subsample of 411 patients, of the 72% who had weekly side-effect assessments documented in the first month of treatment, a structured assessment tool had been used in 29%. Treatment monitoring up to 18 weeks included an ECG in 90%, C-reactive protein (CRP) or creatine kinase in 42%, and troponin or B-type natriuretic peptide (BNP) in 29%. In the 5908 patients prescribed clozapine for at least 1 year, blood pressure and body weight/body mass index were documented in at least 80%, plasma lipids in 78% and plasma glucose in 73%, with an ECG in 55%. Two-thirds were prescribed medication to manage side effects of clozapine and one third of those with a diagnosis of schizophrenia were prescribed a second antipsychotic medication.Conclusion:The findings suggest that for most patients treated with clozapine in UK mental health services, physical health screening and side-effect monitoring follow recommended practice, but there was limited use of structured side-effect assessment tools. Monitoring for clozapine-induced myocarditis during the early risk period using markers of inflammation such as CRP, and cardiac damage such as troponin and BNP, was less consistent. This may partly reflect the variation in guideline recommendations for monitoring for myocarditis and partly the selected use of such tests when prompted by cardiac symptoms. The relatively common coprescription of medications for the majority of people on longer-term clozapine treatment may well further increase side-effect burden and physical health risks, reinforcing the need for continuing systematic monitoring.

SA83. Brain Glutamate Levels and Antipsychotic Response in Schizophrenia

Background: There is considerable interest in identifying biomarkers of antipsychotic response in schizophrenia, and brain glutamate is one key candidate. Methods: In a series of 1H-MRS studies, we have investigated the relationship between brain glutamate and antipsychotic response. This includes cross-sectional studies in patients with early psychosis,1 and chronic schizophrenia.2,3 Longitudinally, within the OPTiMiSE consortium, we examined whether glutamate levels in first-episode psychosis (FEP; n = 72, <2 weeks antipsychotic medication) predict psychopathology after subsequent administration of oral amisulpride for 4 weeks. Finally, in an ongoing study in treatment-resistant schizophrenia, we investigate whether glutamate levels prior to clozapine initiation predict the degree of symptomatic response after 12 weeks of clozapine treatment. Results: The cross-sectional study in early psychosis1 found elevated glutamate in the anterior cingulate cortex (ACC) in patients who had reached remission compared to those who had not (T(30) = 3.02; P = .005). ACC glutamate level was positively associated with the severity of negative symptoms (r = .42; P = .017) and negatively associated with of global functioning (r = .47; P = .007). Our first cross-sectional study in chronic schizophrenia2 detected an elevation in ACC glutamate in treatment-resistant schizophrenia (TRS) compared to healthy volunteers (T(14) = 2.80, P = 0.01), which was not apparent in treatment responders (T(16) = 0.29, P = .77). The subsequent larger study3 found higher ACC glutamate levels in TRS than in treatment-responsive patients (T(35) = 2.34, P = .025). In the OPTiMiSE FEP cohort at baseline (prior to amisulpride treatment), ACC glutamate was positively correlated with the PANSS general score (r = .26; P = .03) and negatively correlated with the personal and social performance (PSP) score, (r = −.34; P = .006). Baseline glutamate in the ACC (r = −.38; P = .004) and thalamus (r = −.42; P = .003) were negatively correlated with PSP score after 4 weeks amisulpride. Baseline thalamic glutamate negatively correlated with the longitudinal reduction in the PANSS positive (r = −.35; P = .009) and total (r = −.28; P = .04) scores after 4 weeks amisulpride. An interim update on the ongoing clozapine study will also be provided. Conclusion: This series of studies has returned consistent findings that elevated ACC glutamate is associated with poor response to antipsychotics, more severe symptoms, and social dysfunction. Brain glutamate may relate to the magnitude of response to subsequent antipsychotic treatment.

Loxapine and Cyproheptadine Combined Limit Clozapine Rebound Psychosis and May Also Predict Clozapine Response.

Clozapine has been consistently shown to be superior to other antipsychotics in the treatment of psychosis. However, clozapine usage has been limited due to required routine blood monitoring and the potential for life threatening side effects. We report a case of a 66-year-old female patient, who developed clozapine-induced agranulocytosis after 10 weeks of clozapine treatment and was subsequently successfully treated with a combination of loxapine and cyproheptadine. The combination is thought to mimic the pharmacological profile of clozapine, rendering it as a possible alternative to traditional clozapine treatment.

Diurnal neurobiological alterations after exposure to clozapine in first-episode schizophrenia patients

BackgroundIrregular circadian rhythm and some of its most characteristic symptoms are frequently observed in patients with schizophrenia. However, changes in the expression of clock genes or neuropeptides that are related to the regulation of circadian rhythm may influence the susceptibility to recurrence after antipsychotic treatment in schizophrenia, but this possibility has not been investigated. MethodsBlood samples were collected from 15 healthy male controls and 13 male schizophrenia patients at 4h intervals for 24h before and after treatment with clozapine for 8 weeks. The outcome measures included the relative expression of clock gene mRNA PERIOD1 (PER1), PERIOD2 (PER2), PERIOD3 (PER3) and the levels of plasma cortisol, orexin, and insulin. ResultsCompared with healthy controls, schizophrenia patients presented disruptions in diurnal rhythms of the expression of PER1, PER3, and NPAS2 and the release of orexin, accompanied by a delayed phase in the expression of PER2, decreases in PER3 and NPAS2 expression, and an increase in cortisol levels at baseline. Several of these disruptions (i.e., in PER1 and PER3 expression) persisted after 8 weeks of clozapine treatment, similar to the decreases in the 24-h expression of PER3 and NPAS2. Clozapine treatment for 8 weeks significantly decreased the 24-h levels of PER2 and increased the 24-h levels of insulin. ConclusionThese persistent neurobiological changes that occur after 8 weeks of clozapine treatment may contribute to the vulnerability to recurrence and efficacy of long-term maintenance treatment in schizophrenia.

Relationship between clinical improvement and functional gains with clozapine in schizophrenia

Impairment in psychosocial functioning is a key feature in schizophrenia, but few studies have examined the relationship between improvements in symptoms and functioning. We examined the relationship between change in symptoms and change in functioning in a group of patients with treatment-resistant schizophrenia after 6 and 12 weeks of clozapine treatment. Participants were assessed prior to clozapine and again at 6 and 12-week on the 18-item Brief Psychiatric Rating Scale (BPRS) and the Social and Occupational Functioning Scale (SOFAS). Change scores in BPRS and SOFAS at 6 and 12-week post-clozapine were calculated and the direct relationship was assessed via regression models. Forty-three participants were included in this study; age of sample was 42.1±12.7 years, with 31 (72.1%) male participants. At baseline, the mean BPRS total and SOFAS scores were 46.98±12.86 and 33.07±10.79, respectively. There were significant improvements in BPRS total and SOFAS scores at 6 weeks, but no significant differences between 6 and 12-week assessments. There was no significant change in negative symptoms at both follow-up assessments. At 6-week, change in symptoms was not correlated with change in functioning and while the relationship between change in symptoms and functioning was stronger at 12 weeks, none of the BPRS factors emerged as a significant predictor. The present study found that lower baseline SOFAS score was the most robust predictor for improvements in SOFAS at 6 and 12-weeks. There appears to be a “ceiling” for functional improvements on clozapine, but follow-up studies are needed to examine functional gains beyond 12 weeks.

Effect of clozapine on white matter integrity in patients with schizophrenia: A diffusion tensor imaging study

Several diffusion tensor imaging (DTI) studies have reported disturbed white matter integrity in various brain regions in patients with schizophrenia, whereas only a few studied the effect of antipsychotics on DTI measures. The aim of this study was to investigate the effect of 12 weeks of clozapine treatment on DTI findings in patients with schizophrenia, and to compare the findings with those in unaffected controls. The study included 16 patients with schizophrenia who were assessed with the Positive and Negative Syndrome Scale, a neurocognitive test battery, and DTI at baseline and 12 weeks after the initiation of clozapine treatment. Eight unaffected controls were assessed once with the neurocognitive test battery and DTI. Voxel-wise analysis of DTI data was performed via tract-based spatial statistics (TBSS). Compared with the control group, the patient group exhibited lower fractional anisotropy (FA) in 16 brain regions, including the bilateral superior longitudinal fasciculi, inferior fronto-occipital fasciculi, superior and inferior parietal lobules, cingulate bundles, cerebellum, middle cerebellar peduncles, and left inferior longitudinal fasciculus, whereas the patients had higher FA in six regions, including the right parahippocampus, left anterior thalamic radiation, and right posterior limb of the internal capsule before clozapine treatment. After 12 weeks of treatment with clozapine, white matter FA was increased in widespread brain regions. In two of the regions where FA had initially been lower in patients compared with controls (left inferior fronto-occipital fasciculus and superior parietal lobule), clozapine appeared to increase FA. An improvement in semantic fluency was correlated with the increase in FA value in the left inferior fronto-occipital fasciculus. An increase in FA following 12 weeks of treatment with clozapine suggests that this treatment alters white matter microstructural integrity in patients with schizophrenia previously treated with typical and/or atypical antipsychotics and, in some locations, reverses a previous deficit.

Poster #M55 DURATION OF ILLNESS ASSOCIATED WITH CORTICAL THICKNESS CHANGE IN SCHIZOPHRENIA: A LONGITUDINAL MRI STUDY

Several diffusion tensor imaging (DTI) studies have reported disturbed white matter integrity in various brain regions in patients with schizophrenia, whereas only a few studied the effect of antipsychotics on DTI measures. The aim of this study was to investigate the effect of 12 weeks of clozapine treatment on DTI findings in patients with schizophrenia, and to compare the findings with those in unaffected controls. The study included 16 patients with schizophrenia who were assessed with the Positive and Negative Syndrome Scale, a neurocognitive test battery, and DTI at baseline and 12 weeks after the initiation of clozapine treatment. Eight unaffected controls were assessed once with the neurocognitive test battery and DTI. Voxel-wise analysis of DTI data was performed via tract-based spatial statistics (TBSS). Compared with the control group, the patient group exhibited lower fractional anisotropy (FA) in 16 brain regions, including the bilateral superior longitudinal fasciculi, inferior fronto-occipital fasciculi, superior and inferior parietal lobules, cingulate bundles, cerebellum, middle cerebellar peduncles, and left inferior longitudinal fasciculus, whereas the patients had higher FA in six regions, including the right parahippocampus, left anterior thalamic radiation, and right posterior limb of the internal capsule before clozapine treatment. After 12 weeks of treatment with clozapine, white matter FA was increased in widespread brain regions. In two of the regions where FA had initially been lower in patients compared with controls (left inferior fronto-occipital fasciculus and superior parietal lobule), clozapine appeared to increase FA. An improvement in semantic fluency was correlated with the increase in FA value in the left inferior fronto-occipital fasciculus. An increase in FA following 12 weeks of treatment with clozapine suggests that this treatment alters white matter microstructural integrity in patients with schizophrenia previously treated with typical and/or atypical antipsychotics and, in some locations, reverses a previous deficit.

Editorial – October 2013

Clozapine was first synthesized more than 50 years ago but we are still using it, discussing it and finding out more about it. It is famously effective in refractory schizophrenia, for which it is both widely used and underused. It is also effective in bipolar disorder and psychosis associated with Parkinson’s disease, amongst other conditions. In this issue, Zarzar and McEvoy report on four compelling cases of clozapine reducing suicidal thoughts and self-harming activities in hospitalized patients with borderline personality disorder. In each case, the patient was highly suicidal and aggressive but after a few weeks of clozapine treatment (at what would normally be considered ‘subtherapeutic’ plasma concentrations) each patient was well enough to be discharged. Of course, clozapine’s beneficial effect on suicidality is well known in schizophrenia. These four cases suggest its antisuicidal effect is rather broader than previously thought. Clozapine treatment is often delayed because of fears about the drug’s wide range of potentially fatal adverse effects. The best known of these is neutropenia/agranulocytosis. When agranulocytosis occurs and is thought to be caused by clozapine, re-challenge is not often attempted. Granulocyte colony-stimulating factor (G-CSF) has occasionally been used for neutropenia occurring in patients taking clozapine, although only rarely when clozapine was thought to be the causative agent. Khan and colleagues describe three successful uses of G-CSF in patients in a secure setting with probable clozapine-induced neutropenia. That re-challenge was even considered (and then found to be effective) is perfect testament to clozapine’s efficacy. Three other case reports in this issue describe the resolution of difficulties associated with the use of clozapine. In one, the testosterone-suppressing drug goserelin was used to treat recurrent clozapine-induced priapism (a rare adverse effect of clozapine). In another, three metabolic inhibitors were used in turn to increase clozapine plasma concentrations: fluoxetine was too weak, fluvoxamine too strong, and cimetidine just right. In the third, a description of haematemesis related to clozapine-induced oesophagitis, resolution was achieved only by permanent discontinuation of clozapine. Also in this issue, a team from eastern England report on their very successful programme aimed at improving lithium monitoring, and workers and students from Iowa, USA review mechanisms involved in the effects of antipsychotics on the skeletons of young people.

QTc prolongation: is clozapine safe? Study of 82 cases before and after clozapine treatment

The most feared cardiological consequence of clozapine is sudden cardiac death. A potential marker of it is QTc interval (QTc) prolongation. This study aimed to determine the prevalence of QTc prolongation in patients before and after 18 weeks of clozapine treatment and to detect predictors of QTc prolongation. Patients undergoing treatment with clozapine who had been given an electrocardiogram prior to the treatment and had their electrocardiogram, serum clozapine and norclozapine levels taken on the 18th week were selected. Exclusion criteria were thioridazine, pimozide, diuretics or beta-blocker treatment, electrolytic alteration, heart diseases and substance misuse diagnosis. Prolonged QTc was defined as >450 ms in men and >470 ms in women. No significant differences were detected in prevalence of prolonged QTc or mean QTc before and after 18 weeks of clozapine treatment (p = 0.15, p = 0.32, respectively). Age, heart rate at 18th week and QTc prior to clozapine treatment had significant effects on QTc at follow-up. Prolonged QTc during previous treatment and heart rate >95 beats/min at 18 weeks were found to be predictors of QTc prolongation. No significant differences were detected in prevalence of QTc prolongation or mean QTc among patients before and after 18 weeks on clozapine.

P03-73 - Myocarditis and cardiomyopathy: severe complications of clozapine treatment

IntroductionClozapine has several major side-effects for example agranulocytosis. There are however several severe cardiac side-effects associated with the use of clozapine.We present two psychotic patients, who were treated with clozapine. One patient developed myocarditis and the other patient developed cardiomyopathy. These findings raised questions about the frequency of cardiac side-effects due to clozapine treatment.ObjectivesAwareness of cardiotoxic side-effects of clozapine; Creation of a clinical guideline for myocarditis and cardiomyopathy in clozapine treatmentMethodsTwo case reports, one male 57 years, suffering from paranoid schizophrenia developing myocarditis, the other a female of 62 years also suffering from paranoid schizophrenia, developing cardiomyopathy during clozapine treatment are presented.Secondly, an extensive literature search with keywords: Myocarditis; cardiomyopathy, heartfaillure and clozapine has been performed.ResultsThe incidence of myocarditis and cardiomyopathy associated with clozapine use are possibly around 1 percent, 10-100 times higher than previously assumed.ConclusionMyocarditis and cardiomyopathy are cardiac side-effects of clozapine use which are severe and have a possible fatal outcome. Diagnosis of namely myocarditis can be difficult.Research suggests that these side-effects might be less rare as thought of until recently. A clinical guideline for monitoring of these side-effects didn’t really exist to this moment. A proposition for a clinical guideline has been made in this presentation consisting of namely: anamnestic findings laboratory tests and ECG controls. Awareness for myocarditis is especially necessary during the first 4 weeks of clozapine treatment.

The effect of clozapine on regional cerebral blood flow and brain metabolite ratios in schizophrenia: Relationship with treatment response

The purpose of this study was to investigate the effect of clozapine on regional cerebral blood flow (rCBF) and its relationship with response to treatment. In addition, we aimed to study the influence of clozapine on proton magnetic resonance spectroscopy ( 1H-MRS) findings in the dorsolateral prefrontal cortex (DLPFC) in a subgroup of patients. Psychopathology, neurocognitive functioning, and SPECT imaging of 22 patients were assessed at the baseline and 8 weeks after the initiation of clozapine treatment. In 10 of these patients intermediate-echo (TE: 135 ms) single-voxel 1H-MRS was also performed at the baseline and after 8 weeks. Clozapine treatment increased the right frontal (superior and medial)/caudate perfusion ratio in the whole group, while it increased bilateral frontal (superior and medial)/caudate perfusion ratios in treatment responders. In addition, percentage changes in left and right frontal (superior and medial)/caudate perfusion ratios compared to the baseline were higher in treatment responders than in non-responders. The improvement in attention was related to the increase in percentage change in the right frontal (superior and medial)/caudate perfusion ratio, while the improvement in verbal fluency was related to the increase in percentage changes in both right and left frontal (superior and medial)/caudate perfusion ratios and to right frontal (superior and medial)/thalamus perfusion. Baseline frontal (superior and medial)/thalamus perfusion could explain 32% of the variability of percentage improvements in psychopathology. 1H-MRS showed that the baseline PANSS general psychopathology score was inversely correlated with the baseline NAA/Cre ratio. An increased NAA/Cre ratio in DLPFC after 8 weeks of clozapine treatment was also revealed by 1H-MRS. Our SPECT imaging results suggest the presence of an imbalance in fronto-striato-thalamic circuitry that changes with clozapine, especially in the responders, while 1H-MRS results indicate a supportive effect of clozapine on neuronal integrity.

Nonresponse to clozapine and premorbid functioning in treatment refractory schizophrenia

Introduction It is recognized that early treatment can improve outcomes and generally improve recovery potential for those with schizophrenia. Data suggest that poor premorbid functioning has been found to be related to more severe symptoms and poor antipsychotic response; however, little is known about premorbid functioning in patients who have no response to clozapine treatment. Methods This study compares the premorbid functioning among patients who responded to clozapine treatment (20% decrease in total Brief Psychiatric Rating Scale [BPRS] score; n = 35) and those who did not respond (n = 50) to 8 weeks of clozapine treatment. Premorbid functioning was assessed using the Cannon-Spoor Premorbid Adjustment Scale. Results Patients who did not respond to clozapine had significantly lower total BPRS scores ( P = .01) at baseline, driven primarily by lower ratings in hostility ( P = .007) and activation ( P = .02), compared with those who responded to clozapine. Responders and nonresponders did not differ in their age, race, level of education, marital status, age of onset, characterization of the deficit syndrome, and positive or negative symptoms. Nonresponders to clozapine did not improve in any area of symptoms or global functioning, whereas there were significant improvements in BPRS total scores (analysis of covariance) and all symptom domains in the responder groups ( P < .0001). Level of functioning scores in those who responded to clozapine was significantly higher at end point ( P = .02). As for premorbid functioning, there were no differences in scores between responders and nonresponders at the time of early and late adolescence; however, there was a trend toward lower premorbid functioning in the clozapine nonresponders on most childhood measures (before the age of 11 years). Clozapine nonresponders tended to be less social and more withdrawn as compared with those who responded to clozapine ( P = .08), as well as tended to have poorer adaptation to school ( P = .06) and fewer peer relationships ( P = .08). These results did not reach significance. Work and/or school performance changed more insidiously in the nonresponders group before illness onset ( P = .045). Discussion Clozapine is beneficial to many patients with treatment-resistant symptoms; however, nonresponse to this medication may represent a subtype of patients who may present differently with symptoms. These findings should encourage further examination of early childhood indicators and opportunities for appropriate and effective intervention.

Clozapine Treatment of Childhood-Onset Schizophrenia: Evaluation of Effectiveness, Adverse Effects, and Long-Term Outcome

Clozapine is a unique atypical antipsychotic with superior efficacy in treatment-resistant schizophrenia. Plasma concentration of clozapine and its major metabolite N-desmethylclozapine (NDMC) as well as the ratio of NDMC to clozapine have been reported to be predictors of clozapine response. Here we evaluate these as well as other measures in an effort to find predictors of response to clozapine in our early-onset treatment-refractory population. Fifty-four children and adolescents participated in double-blind (n = 22) or open-label (n = 32) clozapine trials. Clinical evaluations took place at baseline, week 6 on clozapine, and at 2- to 6-year follow-up. The data were analyzed in relation to demographics, age at onset, IQ, clozapine dose, and plasma concentrations of prolactin, clozapine, NDMC, and NDMC/clozapine ratio. Stepwise regression and correlation analyses were performed to find predictors of treatment response. Clinical improvement after 6 weeks of clozapine treatment, as measured by the percentage of improvement on the Brief Psychiatric Rating Scale and the Scale for the Assessment of Positive Symptoms, was strongly associated with the NDMC/clozapine ratio at the 6-week time point (Pearson correlation coefficient: r = 0.41; p < .01 for Brief Psychiatric Rating Scale and r = 0.43; p < .01 for Scale for the Assessment of Positive Symptoms). Although the rate of side effects was higher than that typically found in the adult population, it did not appear to be related to clozapine dose, clozapine or NDMC plasma concentrations, or NDMC/clozapine ratio. Outcome at long-term follow-up, as measured by Children's Global Assessment Scale, was associated with lesser illness severity at baseline and with greater improvement during the initial 6 weeks of clozapine treatment. The NDMC/clozapine ratio may be a valuable predictor of response to clozapine and may suggest new approaches to clozapine treatment.