Common Side Effects and Metabolic Syndrome due to Clozapine: Relationship with the Clinical Variables and Disability

OBJECTIVE

Common side effects of clozapine may affect the treatment process negatively. In this study, we aimed to assess the common side effects and the prevalence of metabolic syndrome in schizophrenia patients treated with clozapine, and to study their relationship with clinical variables and disability.

METHOD

One hundred and twenty two patients who met DSM-IV criteria for schizophrenia, and were on clozapine treatment were included in the study. Clinical status was evaluated through a clinical interview and review of the medical records, and physical measures and laboratory tests were recorded. Patients were assessed with the Structured Clinical Interview for DSM-IV Axis I Disorders, UKU (Udvalg for Kliniske Undersogelser) Side Effect Rating Scale, World Health Organization (WHO)-Disability Assessment Schedule II, Positive and Negative Syndrome Scale, Global Assessment Scale, Clinical Global Impression Scale.

RESULTS

Common side effects of clozapine were hypersalivation, fatigue, sedation and constipation. The relationship between constipation and clozapine dose, and dizziness and norclozapine plasma levels were significant. The prevalence of metabolic syndrome was 50%, and patients with metabolic syndrome had higher means of age and lifetime cigarette consumption. Disability was positively correlated with the severity of psychopathology and the number of side effects, and negatively correlated with the age at onset of illness. Severity of the psychopathology and the number of side effects predicted the severity of the disability.

CONCLUSION

Clozapine was associated with various side effects and half of the patients had metabolic syndrome. Assessment of common side effects due to clozapine is important for reducing disability.

Effect of Clozapine on Psychiatric Comorbidities in Patients with Schizophrenia

Introduction

Clozapine has superior efficacy in treatment-resistant schizophrenia, and has various effects on psychiatric comorbidities, which may affect the illness course.

Aims

We aimed to assess the past and current psychiatric comorbidities in schizophrenia patients treated with clozapine, and study their relationship with clinical variables.

Methods

Consecutive 122 outpatients who met DSM-IV criteria for schizophrenia receiving clozapine were included. Information about past and current clinical status were gathered through a clinical interview and review of the medical records, along with laboratory test results. Patients were assessed with structured clinical interview for Axis-I Disorders for DSM-IV, Clinical Global Impression Scale, Positive and Negative Syndrome Scale (PANSS), Calgary Depression Scale, Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Panic and Agoraphobia Scale (PAS), WHO-Disability Assessment Schedule-II.

Results

There was a significant decrease in the diagnosis of depression, alcohol and substance use disorder, number of suicide attempts, and an increase in the diagnosis of obsessive compulsive disorder (OCD) after clozapine initiation. Clozapine related de novo OCD appeared in 48.4% of the patients, and there was a positive correlation between Y-BOCS total scores and clozapine dose and plasma levels. In the de novo OCD group, compulsion scores were higher than obsession scores with checking most prevalent among compulsions. Total PANSS, Y-BOCS, PASscores were positively correlated withtotal disability score.

Conclusions

Clozapine seems to decrease comorbid depression, alcohol and substance use and number of suicide attempts and increase OCD. Assessment and treatment of psychiatric comorbidities in clozapine using schizophrenia patients is vital to decrease disability.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Side Effects of Clozapine and Their Relationship with Clinical Variables in Patients with Schizophrenia

Introduction

The side effects of clozapine may affect the treatment process negatively, and increase the disability.

Aims

We aimed to assess the side effects of clozapine, and their relationship with the clinical variables in schizophrenia patients, and study the predictors of disability.

Methods

Consecutive 122 outpatients who met DSM-IV criteria for schizophrenia, and were on clozapine treatment were included in the study. Information about sociodemographic characteristics, past and current clinical status were gathered through a clinical interview and review of the medical records, and physical measures and laboratory tests, including clozapine plasma levels, were recorded. The patients were assessed with SCID-I, Positive and Negative Syndrome Scale, UKU-Side Effect Rating Scale, WHO-Disability Assessment Schedule-II.

Results

Hypersalivation, weight gain, sedation and constipation were the most common side effects of clozapine. Although the mean plasma clozapine levels were high (828.11 ± 445.5 ng/mL), no significant effect of clozapine dose and plasma levels were detected on the severity of side effects, except for constipation. Metabolic syndrome prevalence was found to be 50% according to ATP IIIA criteria. Duration of clozapine treatment, clozapine dose and plasma levels were not significantly different between patients with and without metabolic syndrome. Regression analysis showed that the severity of schizophrenia psychopathology and the number of side effects predicted the severity of disability.

Conclusions

Side effects of clozapine increase the disability of patients with schizophrenia and should be monitored regularly. On the other hand, clozapine dose and plasma levels do not determine the severity of most of the common side effects.

Disclosure of interest

The authors have not supplied their declaration of competing interest.