Effects of Sex Differences and Combined Use of Clozapine on Initial Dosage Optimization of Valproic Acid in Patients with Bipolar Disorder.

BACKGROUND: Due to the narrow therapeutic window and large pharmacokinetic variation of valproic acid (VPA), it is difficult to make an optimal dosage regimen. The present study aims to optimize the initial dosage of VPA in patients with bipolar disorder. METHODS: A total of 126 patients with bipolar disorder treated by VPA were included to construct the VPA population pharmacokinetic model retrospectively. Sex differences and combined use of clozapine were found to significantly affect VPA clearance in patients with bipolar disorder. The initial dosage of VPA was further optimized in male patients without the combined use of clozapine, female patients without the combined use of clozapine, male patients with the combined use of clozapine, and female patients with the combined use of clozapine, respectively. RESULTS: The CL/F and V/F of VPA in patients with bipolar disorder were 11.3 L/h and 36.4 L, respectively. It was found that sex differences and combined use of clozapine significantly affected VPA clearance in patients with bipolar disorder. At the same weight, the VPA clearance rates were 1.134, 1, 1.276884, and 1.126 in male patients without the combined use of clozapine, female patients without the combined use of clozapine, male patients with the combined use of clozapine, and female patients with the combined use of clozapine, respectively. This study further optimized the initial dosage of VPA in male patients without the combined use of clozapine, female patients without the combined use of clozapine, male patients with the combined use of clozapine, and female patients with the combined use of clozapine, respectively. CONCLUSION: This study is the first to investigate the initial dosage optimization of VPA in patients with bipolar disorder based on sex differences and the combined use of clozapine. Male patients had higher clearance, and the recommended initial dose decreased with increasing weight, providing a reference for the precision drug use of VPA in clinical patients with bipolar disorder.

Evaluating Reduced Blood Monitoring Frequency and the Detection of Hematological Abnormalities in Clozapine-Treated Patients With Schizophrenia: A Chart Review Study From the COVID-19 Pandemic.

BACKGROUND AND HYPOTHESIS: In response to Health Canada's March 2020 directive, patients on clozapine for over 12 months were allowed to extend hematological testing intervals from 4 to 8 weeks during the COVID-19 pandemic. We hypothesized that this change would not affect the timely detection of hematological abnormalities in patients with severe mental illness. STUDY DESIGN: A chart review was conducted of patients at the Royal Ottawa who were prescribed clozapine from March 2019 to March 2021. We analyzed clinical and hematological data from electronic health records and Clozaril Support and Assistance Network database to compare occurrences of hematological abnormalities [leukopenia (white blood cell count <3.5 × 109/L) and agranulocytosis (absolute neutrophil count <0.5 × 109/L)] from March 17, 2020 to March 16, 2021, between standard and extended monitoring protocols using binomial logistic and zero-inflated negative binomial regressions. STUDY RESULTS: Of 621 patients, 196 were on extended blood monitoring, and 425 followed standard blood monitoring. Clozapine dose did not differ between groups (standard: 370 ±â€…201 mg; extended: 352 ±â€…172 mg; P = .14, ds = 0.10). Clozapine treatment duration up to March 2021 was 12.6 ±â€…8.3 years, with the extended group (10 ±â€…7.9 years) having a significantly (P < .01, ds = 0.50) shorter duration than the standard (14 ±â€…8.2 years). Extended monitoring did not significantly impact likelihood of detecting hematological abnormalities (OR = 0.83, 95% CI [0.58,1.41], P = .55) after controlling for age, sex, total bloodwork, and other psychotropics associated with neutrophil counts (ie, valproate, olanzapine). No patient on the extended regimen developed agranulocytosis. CONCLUSIONS: Reducing blood monitoring frequency in patients on clozapine for more than 12 months did not compromise detection of hematological abnormalities.

Co-administration of sub-effective doses of the constituents of Crocus sativus L. crocins with those of the antipsychotics clozapine and risperidone counteract memory deficits caused by blockade of the NMDA receptor in rats.

Experimental evidence indicates that the noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists ketamine and MK-801 induce schizophrenia-like symptoms in rodents, including cognitive deficits. Crocins are among the active components of the plant Crocus sativus L. and were found to be effective in different models of psychiatric disorders comprising schizophrenia. The present study was designed to evaluate the efficacy of the joint administration of sub-effective doses of crocins with those of the atypical antipsychotics clozapine and risperidone in alleviating nonspatial recognition and emotional memory deficits induced either by ketamine (3 mg/kg) or MK-801 (0.1 mg/kg) in the rat. To this end, the object recognition and the step-through passive avoidance tests were used. Co-administration of sub-effective doses of crocins (5 mg/kg) with those of clozapine (0.1 mg/kg) or risperidone (0.03 mg/kg) counteracted nonspatial recognition and emotional memory deficits induced by NMDA receptor antagonists. The current findings suggest that this combinatorial treatment was efficacious in attenuating cognitive impairments related to the blockade of the NMDA receptor. In addition, the present results support the potential of crocins as an adjunctive drug for the therapy of schizophrenia.

Clozapine Safety in Pregnancy: A Clinical Study.

BACKGROUND AND HYPOTHESIS: Pregnant women with persistent schizophrenia and related disorders may require ongoing antipsychotic treatment, including clozapine. However, the potential risks of using clozapine during pregnancy and the postnatal period remain uncertain. STUDY DESIGN: We conducted a nested case-control study using the National Register of Antipsychotic Medication in Pregnancy (NRAMP) database. Our study assessed pregnancy outcomes among Australian women diagnosed with schizophrenia spectrum disorder and treated with clozapine (n = 14) during the first trimester. These women were compared to 2 subgroups: those treated with quetiapine (n = 53) and those not taking any medication (n = 24) during pregnancy. STUDY RESULTS: We observed higher rates of miscarriage in the clozapine group compared to the quetiapine and drug-free groups. The clozapine group had a higher early pregnancy body mass index but lower overall pregnancy weight gain than the other groups. The prevalence of gestational diabetes was significantly higher in the clozapine group. The percentage of vaginal delivery was higher in the clozapine group than in the other 2 groups. Neonatal outcomes such as gestational age, and Apgar scores were similar across groups. The birth weight was lower in the clozapine group compared to the other 2 groups. CONCLUSIONS: This study suggests that pregnant women taking clozapine and their babies have greater adverse outcomes compared to other groups. Clozapine appears to be associated with a greater risk of miscarriages, maternal gestational diabetes, and lower birth weight. However, the gestational age, Apgar scores, and admission to NICU/SCN were comparable between all groups.

Adjunctive clozapine with bright light mitigates cognitive deficits by synaptic plasticity and neurogenesis in sub-chronic MK-801 treated mice.

Schizophrenia impacts about 1 % of the global population, with clozapine (CLZ) being a critical treatment for refractory cases despite its limitations in effectiveness and adverse effects. Therefore, the search for more effective treatments remains urgent. Light treatment (LT) recognized for enhancing cognition and mood, presents a promising complementary approach. This study investigated the effects of CLZ and LT on cognitive impairments in a sub-chronic MK-801 induced schizophrenia mouse model. Results showed that both CLZ and CLZ + LT treatment elevate cognitive performance of sub-chronic MK-801 treated mice in serial behavioral tests over two months. Histological analysis revealed increased dendritic spine density and branching, and synaptic repair in the hippocampus with CLZ and CLZ + LT interventions. Furthermore, both treatments increased brain-derived neurotrophic factor (BDNF) expression in the hippocampus, likely contributing to cognitive amelioration in MK-801 treated mice. Additionally, BrdU labeling revealed that CLZ + LT further enhances neurogenesis in the dentate gyrus (DG) and lateral ventricle (LV) of sub-chronic MK-801 treated mice. These findings may have implications for the development of noninvasive and adjunctive treatment strategies aimed at alleviating cognitive impairments and improving functional outcomes in individuals with schizophrenia.

Severe neutropenia unrelated to clozapine in patients receiving clozapine.

BACKGROUND: Clozapine is known to cause agranulocytosis. Mandatory monitoring schemes are aimed at reducing the risk of agranulocytosis and of the consequences of agranulocytosis. All cases of agranulocytosis occurring in people prescribed clozapine are assumed to be caused by clozapine. METHODS: In a previous study, we examined a cohort of patients listed on our hospital database as having had clozapine-induced agranulocytosis and applied specific criteria to identify those with confirmed clozapine-related, life-threatening agranulocytosis. In this study, we examine the cases not meeting these specific criteria. RESULTS: In the original study, 9 of 23 cases met the criteria for clozapine-induced, life-threatening agranulocytosis. Of the 13 remaining cases for whom data were available, 5 were probably caused by clozapine but were not life-threatening. Three cases were the result of concomitant cancer chemotherapy. Three were anomalous results probably related to measurement error. For the remaining two cases, the cause was not identified. CONCLUSION: Not all cases of agranulocytosis occurring in people taking clozapine are caused by clozapine. The widely used threshold criterion-based diagnosis overestimates the risk of agranulocytosis. True clozapine-related agranulocytosis is best identified by pattern-based criteria: rapid fall in neutrophil counts over around 2 weeks to below 0.5 × 109/L for two consecutive days (unless clozapine is stopped very early or granulocyte colony stimulating factor is given) where other possible causes (benign ethnic neutropenia, cancer chemotherapy) can be ruled out.

Aggressive behaviour and diabetes: A clinical case of atypical metabolic improvement during clozapine treatment.

Aggressive and violent behaviour is a challenging psychiatric emergency to manage, especially among vulnerable categories such as patients with Intellectual Developmental Disorder. Although there is some evidence that clozapine may be useful as an anti-violence compound, its use is limited by common metabolic complications. An adult patient presented with obesity, type II diabetes mellitus, compulsive food intake, severe Intellectual Developmental Disorder, and a treatment-resistant aggressive behaviour. Clozapine was administered resulting in reduced aggressive behaviour. Unexpectedly, a reduction in the food craving as well as a sustained improvement in both anthropometric parameters and glycemic control were observed during the clozapine treatment. Our case report, describes these findings for the first time, highlighting the need for more clinical research to investigate both the efficacy of clozapine in the Intellectual Developmental Disorder populations and its long-term effects with special regard to the metabolic outcomes in this type of patients.

Integrating Physiotherapy in Neuroleptic Malignant Syndrome Management: A Case Report.

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal condition characterized by hyperthermia, autonomic dysregulation, altered mental status, and muscular rigidity. It typically results from the blockade of dopamine receptors by antipsychotic medications. We present the case of a 70-year-old female who developed NMS after non-compliant use of clozapine. She presented with symptoms including irrelevant talk, breathlessness, and generalized muscle weakness. On examination, she was drowsy with a Glasgow Coma Scale score of 11, tachycardia, tachypnea, and hypertonicity in all limbs. Diagnostic evaluations revealed increased urea and creatinine levels, raised creatine phosphokinase, and metabolic acidosis, which are consistent with NMS. Medical management included the discontinuation of clozapine and the initiation of bromocriptine. The report emphasizes how important physical therapy is to the NMS recovery process. The goals of physical therapy were to improve functional mobility, lessen muscle rigidity, and avoid problems from extended immobility. Kinesthetic stimulation, active cycle breathing methods, soft rocking motions, neural warmth, weight-bearing exercises, and mobility training were all incorporated into the protocol. Significant progress was observed in the patient's degree of consciousness, movement, and oxygen reliance over a two-week period. With the patient eventually managing room air without additional oxygen, the Glasgow Coma Scale score improved, and the ICU Mobility Scale score increased from 1 to 5. This instance emphasizes the need for prompt diagnosis and all-encompassing NMS care, with physiotherapy playing a critical role. Physiotherapy can significantly enhance overall healing, improve respiratory function, and facilitate neuromuscular re-education through tailored therapies. The results indicate that physiotherapy has to be regarded as a crucial component of the multidisciplinary strategy for managing NMS, with the goal of enhancing patient outcomes and quality of life. More studies are required to optimize physiotherapy interventions for NMS patients.

Quetiapine, Clozapine, and Pimavanserin Treatment Response in Monogenic Parkinson's Disease Psychosis: A Systematic Review.

Psychotic symptoms frequently occur in idiopathic Parkinson's disease (PD) and often require treatment with antipsychotic therapy. Most antipsychotics have the potential to worsen the motor symptoms of PD; quetiapine, clozapine, and pimavanserin are commonly used for the treatment of idiopathic PD because these medications tend to be comparatively well tolerated. Although psychotic symptoms may also occur in monogenic forms of PD, no reviews have focused on the use of antipsychotic medications in this context. The objective of the present systematic review was to characterize the effectiveness and tolerability of quetiapine, clozapine, and pimavanserin in monogenic PD-associated psychosis. A literature search was performed with PubMed, Scopus, and Embase. The search yielded 24 eligible articles describing 30 individuals, although treatment response with respect to psychotic symptoms was described in only 11 cases; of these, six individuals experienced symptomatic improvement or remission (four with clozapine and two with quetiapine), two exhibited a poor therapeutic response (one to clozapine and one to quetiapine), and the other three responded initially to antipsychotic therapy before experiencing a recurrence of symptoms. The use of quetiapine and clozapine in GBA variant-associated PD is briefly reviewed separately. Notably, no reports of pimavanserin therapy were identified. In keeping with the idiopathic PD literature, relatively low doses of medication were used in most cases. Lastly, side effects were rarely reported. Although quetiapine and particularly clozapine may be effective and well tolerated in the treatment of monogenic PD psychosis, this review highlights the paucity of available evidence to guide clinical decision making in this context.

Comparative Effectiveness of Amisulpride and Clozapine in the Treatment of Schizophrenia: A Systematic Review and Meta-Analysis.

In approximately one-third of individuals with schizophrenia, the illness demonstrates a poor response to standard antipsychotic treatments. Although a relatively small proportion fails to achieve remission after the initial exposure to either first- or second-generation antipsychotic drugs, the condition often becomes progressively more resistant to medication following subsequent relapses. We conducted comprehensive searches in databases such as PubMed and PubMed Central, extracting and assessing data quality using the Cochrane risk-of-bias tool for randomized clinical trials (RCTs). A random effects model was employed to calculate the pooled prevalence and explore heterogeneity, utilizing the I2 statistic. Subgroup analyses differentiated between experimental and placebo groups, while sensitivity analyses assessed the robustness of our findings, and publication bias was examined. Our meta-analysis included a sample size of 323 patients from seven studies out of the 10 selected articles. The pooled sample evaluated the effectiveness of amisulpride and clozapine in treating schizophrenia, with Positive and Negative Syndrome Scale (PANSS)-positive and PANSS-negative scores used in the subgroup analysis. The analysis revealed a heterogeneity of 78% and a statistically significant p-value of <0.05, favoring amisulpride and clozapine for treating schizophrenia either as monotherapy or in combination. These findings indicate that the effectiveness of these drugs is statistically significant. Our study underscores the necessity of conducting larger RCTs to further elucidate the optimal dosage and guideline criteria for prescribing amisulpride, clozapine, or their combination for patients resistant to first- and second-generation antipsychotics.

Clozapine levels and outcomes in Serbian patients with treatment-resistant psychotic disorders previously treated without measuring clozapine levels (CLOSER).

Clozapine remains the only pharmacological treatment option for treatment-resistant schizophrenia. Therapeutic drug monitoring (TDM) of clozapine is recommended, although evidence for the therapeutic range of 350-600 ng/ml is limited. In various countries including Serbia, TDM of clozapine is not routinely performed. This study evaluated the distribution of clozapine levels and their relationship with clinical outcomes in Serbian patients who had not undergone prior TDM. 140 Patients with treatment-resistant schizophrenia and schizo-affective disorder were enrolled. Clozapine levels were measured by dried blood spot (DBS) analysis. Side effects were evaluated by GASS-c, severity of symptoms and functional impairment with WHODAS, CGI-S and GAF. Of the patients, 51.2% had subtherapeutic levels, 24.8% were in the therapeutic window, and 24% had supratherapeutic levels. Clozapine levels showed no association with side effects and a weak positive association with symptom severity and functional impairment. No serious side effects were observed in patients with clozapine levels surpassing 1000 ng/ml (n = 8). Based on these findings, we propose that the upper limit of the therapeutic range should not be regarded as an absolute barrier, and guidelines should allow for a personalized approach when prescribing clozapine.

Clozapine as a mood stabiliser for schizoaffective disorder: Effectiveness during a three-month follow-up.

Clozapine has shown signs of effectiveness in treating symptoms of schizoaffective disorder, although little research has been carried out to specifically assess this question. The objective of this current work was to analyse the mood-stabilising effectiveness and tolerability of clozapine in patients with schizoaffective disorder. This was a prospective, longitudinal, and quasi-experimental trial with three months of follow-up in patients with refractory schizoaffective disorder (PANSS score exceeding 80). Clinical response was evaluated through monthly visits using the YMRS, MADRS, CDSS, CGI-S and UKU. Twenty-seven participants (63% men, 37% women) with a mean age of 32.56 years were included. Clozapine significantly reduced the symptoms of mania, as measured by the YMRS (pre-treatment: 16.19, post-treatment: 0.67; p < 0.01) as well as the symptoms of depression, quantified with the CDSS (pre-treatment: 6.11, post-treatment: 0.67; p < 0.01), MADRS (pre-treatment: 9.56, post-treatment: 1.07; p < 0.01), and CGI-S (pre-treatment: 4.74, post-treatment: 1.15; p < 0.01). The prescription of clozapine significantly reduced the average daily dose of neuroleptics, measured in mg of chlorpromazine (pre-treatment: 1253.55, post-treatment: 742.59; p < 0.01) and hypnosedatives, measured in mg of diazepam (pre-treatment: 33.88, post-treatment: 5.74; p < 0.05) required in these patients. Patient-perceived tolerability, measured with the UKU, also improved during follow-up (pre-treatment: 12.89, post-treatment: 8.14; p < 0.01). The efficacy of clozapine was significant for the affective symptoms of schizoaffective disorder, thereby improving patient tolerability and permitting reductions in the other medications the patients used.

Case report: Time response of plasma clozapine concentrations on cessation of heavy smoking.

Smoking cessation in patients treated with clozapine might lead to elevated plasma concentrations and severe side effects. This case report investigated the trajectory of clozapine plasma concentrations over time after smoking cessation in a Chinese inpatient with schizophrenia. This case report delineates the temporal response of plasma clozapine concentrations and dose-corrected clozapine plasma concentrations in a 33-year-old inpatient with schizophrenia who had a substantial smoking history and ceased smoking abruptly during dose titration. This case report presents a sudden increase in plasma clozapine concentrations and dose-corrected plasma clozapine concentrations after smoking cessation, followed by a rapid decline in dose-corrected plasma clozapine concentrations during the initial 2 weeks and a return to pre-cessation levels approximately 1 month later. The findings suggest that clinicians and pharmacists should adjust clozapine dosage in accordance with changes in smoking status, taking into consideration the temporal effects. Post-smoking cessation adjustments to clozapine dosage should be coupled with therapeutic drug monitoring, especially for patients with heavy smoking habits. Moreover, the advice of the clinical pharmacist should be considered in complex cases to ensure safe use of clozapine.

Comparative effectiveness of clozapine and non-clozapine atypical antipsychotics provided by the Brazilian National Health System in adults with schizophrenia.

Introduction: Currently, 21 million people live with the disease, mostly in low to middle-income countries. We aimed to assess the survival of patients with schizophrenia using clozapine compared with non-clozapine atypical antipsychotics provided by the Brazilian National Health System using real-world data. Materials and methods: This is an open retrospective cohort study of patients diagnosed with schizophrenia to whom atypical antipsychotics were dispensed by the Brazilian National Health System between 2000 and 2015, based on deterministic-probabilistic pairing of administrative data records. The Kaplan-Meier method was used to estimate the cumulative probability of survival and the Cox proportional hazards model was adjusted to assess the risk factors for survival via the hazard ratio (HR). Result: Participants were 375,352 adults with schizophrenia, with an overall survival rate of 76.0% (95%CI 75.0-76.0) at the end of the cohort. Multivariate analysis indicated a greater risk of death for men (HR=1.30; 95%CI 1.27-1.32), older adults (HR=17.05; 95%CI 16.52-17.60), and in the Southeast region of Brazil (HR=1.20; 95%CI 1.17-1.23). Patients who used non-clozapine atypical antipsychotics had a 21% greater risk of death when compared to those taking clozapine (HR=1.21; 95%CI 1.14-1.29). Additionally, a history of hospitalization for pneumonia (HR=2.17; 95%CI 2.11-2.23) was the main clinical variable associated with increased risk of death, followed by hospitalization for lung cancer (HR=1.82; 95%CI 1.58-2.08), cardiovascular diseases (HR=1.44; 95%CI 1.40-1.49) and any type of neoplasia (HR=1.29; 95%CI 1.19-1.40). Discussion: This is the first published Brazilian cohort study that evaluated survival in people with schizophrenia, highlighting the impact of atypical antipsychotics. In this real-world analysis, the use of clozapine had a protective effect on survival when compared to olanzapine, risperidone, quetiapine, and ziprasidone.

Use of Clozapine in persons with a history of seizures: A retrospective study.

BACKGROUND: Seizures are considered to be one of the dreaded side effects of clozapine, and due to this, the use of clozapine is avoided in patients with treatment-resistant schizophrenia. Resultantly, there is little information about the use of clozapine among patients with seizure disorder. AIM: To assess the safety of clozapine in patients with history of seizures in their lifetime before starting clozapine and receiving clozapine for the management of psychotic disorders. RESULTS: Out of the 958 patients, 35 (3.65 %) had a history of at least one seizure episode before starting clozapine, with a mean of 5.06 (SD: 7.23; Median: 3.00) seizures before starting clozapine. The mean duration between the last seizure and the starting of clozapine was 123.75 (SD: 124.99; Median: 84) months, with nine patients having an episode of seizure in the previous 12 months and 15 patients being seizure-free for more than ten years. About one-fourth (25.7 %; nine out of 35) of the patients had recurrence of seizure while receiving clozapine for a mean duration of about five years. When the recurrence of seizure after starting clozapine was evaluated in patients receiving antiepileptics along with clozapine, the incidence of at least one seizure was 26.67 % (4 out of 15), and among those not receiving antiepileptics, the incidence of at least one seizure was 25 % (5 out of 20). The dose of clozapine at which seizure was noted ranged from 12.5 mg to 600 mg/day with a mean of 236.25 (SD: 169.04; Median: 162.5) mg/day. In none of the patients, clozapine had to be stopped due to the continuation of seizures. CONCLUSION: About one-fourth of the patients with history of an episode of seizure have recurrence of seizure while receiving clozapine. The demographic and clinical variables do not differ between those who develop and who do not develop seizures after starting clozapine, including concomitant use of antiepileptics.

An experience of using Clozapine in elderly patients with mental disorders.

BACKGROUND: There is little information on using clozapine in elderly patients with mental disorders from India. AIM: To evaluate the sociodemographic and clinical profile of elderly (age ≥ 60 years) patients started on clozapine. METHODOLOGY: The clozapine registry in the department was screened to identify elderly patients who were started on clozapine. Treatment records of these patients were reviewed to extract sociodemographic and clinical details. RESULTS: Out of the available information of 1058 patients in the registry, 42 (3.96 %) were elderly (≥ 60 years) patients. About two-thirds of the patients had treatment resistance, i.e., their psychotic illness had not responded to two adequate trials of antipsychotics, and the second most common indication for starting clozapine was tardive dystonia or tardive dyskinesia (23.8 %). The mean dose of clozapine was 135.89 (SD: 109.6; Range: 37.5-500; median: 87.5) mg/day. The mean duration of clozapine use at the time of data extraction for the study sample was 3.55 (SD: 2.15; Range 0.3-9; median: 3) years. At the last follow-up, about three-fourths of patients were experiencing at least one side effect, with constipation being the most common side effect, followed by sedation, weight gain, and hypersalivation. In only four patients, clozapine was stopped during the follow-up. In terms of effectiveness, majority of the patients were rated as much improved or very much improved on Clinical Global Impression-Improvement subscale. CONCLUSION: Clozapine can be safely used in elderly patients with mental disorders. Hence, clozapine should not be withheld in elderly patients with mental disorders whenever indicated.

Successful utilization of clozapine for a patient with treatment-resistant schizophrenia after recurrent violent behavior.

BACKGROUND: In patients with schizophrenia, violent behavior is a clinically important factor that prevents their discharge. Clozapine is an effective antipsychotic medication for treatment-resistant schizophrenia, and its usefulness for aggressive behavior has also been suggested. CASE PRESENTATION: We present the case of a 38-year-old male patient diagnosed with schizophrenia who was successfully treated with clozapine after recurrent violent behavior. He was diagnosed with schizophrenia during his adolescence. He was hospitalized for treatment in his teens, but his hallucinations and delusions persisted even after discharge. In his 30s, he became noticeably emotionally unstable, and despite being treated for an adequate period with sufficient doses of several antipsychotics, his symptoms did not improve. This led to repeated hospitalizations triggered by violent behavior toward his parents and siblings within the home. During his fourth hospitalization, clozapine was initiated due to multiple incidents of violence toward nursing staff secondary to hallucinations and delusions. As the dose of clozapine was gradually increased with therapeutic drug monitoring, the patient's hostility, uncooperativeness, and suspiciousness markedly improved, and his aggressive behavior disappeared. He was discharged to a facility on day 194 after starting clozapine and has continued outpatient visits. CONCLUSION: Clozapine was suggested to be effective for aggressive behavior in patients with treatment-resistant schizophrenia and should be actively considered. In such cases, regular measurement of blood concentration is useful for adjusting the dosage of clozapine.

Paralytic ileus in a patient on clozapine therapy showing an inverted clozapine/norclozapine ratio after switching valproic acid to carbamazepine: a case report.

This case report examines the possible correlation between the clozapine/norclozapine ratio and the occurrence of constipation and paralytic ileus. We present the case of a 42-year-old patient diagnosed with schizoaffective disorder undergoing clozapine therapy. Despite intensive treatment with clozapine, haloperidol, valproic acid and biweekly electroconvulsive therapy sessions for over a year, florid psychotic symptoms and fluctuating mood swings persisted. Therefore, valproic acid was replaced by carbamazepine, a potent inducer of several CYP450-enzymes. To maintain clozapine plasma levels, fluvoxamine, a CYP1A2-inhibitor, was introduced at a dose of 25 mg before this switch. After addition of carbamazepine, there was a significant decline in clozapine levels, necessitating an increase in fluvoxamine dosage to 50 mg. Five weeks later the patient was admitted to a general hospital with a diagnosis of paralytic ileus. Treatment with enemas proved effective. Drug concentration analysis revealed a 2.5-fold increase in norclozapine levels in the weeks preceding hospital admission, resulting in an inverted clozapine/norclozapine ratio. Treatment with clozapine, carbamazepine and fluvoxamine was continued as the patient demonstrated clinical improvement on carbamazepine. Concurrently, an intensive laxative regimen was initiated. Two weeks later, the patient was readmitted to the general hospital due to suspected paralytic ileus and faecal vomiting, once again displaying an inverted clozapine/norclozapine ratio. We discuss potential mechanisms contributing to the occurrence of the paralytic ileus in this patient, including the antagonism of muscarinic M3 receptors by both clozapine and norclozapine, as well as the agonism of delta-opioid receptors by norclozapine. This case highlights the potential significance of both the clozapine/norclozapine ratio and absolute norclozapine levels as risk factors for constipation and paralytic ileus in patients on clozapine therapy.

Understanding clozapine-related blood dyscrasias. Developments, genetics, ethnicity and disparity: it's a CIN.

Clozapine remains the gold standard intervention for treatment-resistant schizophrenia; however, it remains underused, especially for some minority groups. A significant impediment is concern about propensity to neutropenia. The aim of this article is to provide an update on current knowledge relating to: the pattern and incidence of severe blood dyscrasias; the effectiveness of current monitoring regimes in reducing harm; the mechanisms of and the distinctions between clozapine-induced neutropenia and agranulocytosis; benign ethnic neutropenia; and changes to the monitoring thresholds in the USA and other international variations. These all have implications for the practical use of clozapine; specifically, how barriers to initiating, maintaining and restarting clozapine can be understood and in many cases overcome, especially for patients from minority groups, potentially with simpler approaches than the use of lithium or G-CSF.