“Long-acting” olanzapine in maintenance therapy of schizophrenia: A study with plasma levels

Abstract

Introduction. This prospective study was performed to evaluate clinical efficacy and tolerability of olanzapine long-acting injection (OLZ-LAI) and the relation between OLZ plasma level (PL) and the clinical outcome in maintenance therapy of schizophrenia. Material and methods. Twenty-five chronic schizophrenic outpatients with age ranging from 18 to 65 years were included in this 9-month study. Patients were given a dosage of either 210 or 300 or 405 mg of OLZ-LAI every 28 days. Patients were evaluated at baseline and every four weeks by Brief Psychiatric Rating Scale (BPRS) and Positive and Negative Symptom Scale (PANSS); at the same time, PL of OLZ was determined. The metabolic profile (aspartate aminotransferase, alanine aminotransferase, high-density lipoprotein, low-density lipoprotein, total cholesterol, and glucose levels) was analyzed every two months. Results. BPRS and total PANSS showed a statistically significant improvement from T₂ with a clinical stabilization of psychopathological picture. PL ranged from 4.0 to 78.9 ng/ml (mean 20.59 ng/ml ± 14.66 standard deviation). The coefficient of variation of PLs was related to clinical stabilization. No post-injection delirium sedation syndrome occurred. Conclusions. Our data reveal the efficacy of OLZ-LAI in maintenance treatment of schizophrenia at lower dosages also in comparison with that of oral therapy. OLZ-LAI seems to be useful for guaranteeing constant PL of the drug. A lesser variation of PL was the most predictable factor associated with maintenance of clinical benefit.

Key words::

• Long-acting olanzapine
• schizophrenia
• plasma levels
• olanzapine depot

Acknowledgements

None.

Statement of interest

The authors disclose no conflict of interests. No financial support or compensation has been received from any individual or corporate entity for research or professional service and there are no personal financial holdings that could be perceived as constituting a potential conflict of interest.