Combination of Olanzapine With Opioid-Agonists in the Treatment of Heroin-Addicted Patients Affected by Comorbid Schizophrenia Spectrum Disorders

Abstract

The objective of this study was to evaluate the efficacy of olanzapine (OLA) in heroin-dependent patients affected by comorbid schizophrenia spectrum disorders (SSD). Sixty-one patients who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for heroin dependence and the criteria for SSD (schizophrenia and schizotypal and schizoaffective-bipolar disorders) were treated in a 12-week prospective observational trial of substitution treatment in combination with OLA or typical antipsychotic haloperidol. Patients were included into 2 subgroups, in relationship with treatment, for the evaluation of the end points at week 12: group 1, SSD treated with OLA (35 patients); group 2, SSD treated with haloperidol (26 patients). Efficacy measures were retention in treatment, Symptoms Checklist-90 score changes, negative urinalyses results, and craving reduction. The rate of patients who remained in treatment at week 12 in group 1 SSD, treated with OLA, was significantly higher (32[91.4%]) than that of group 2 SSD (13 [50%]), treated with the typical antipsychotic (P < 0.001). The decrease in Symptoms Checklist-90 total scores from baseline, as expression of an improvement in comorbid psychopathology in the patients who completed the treatment, was significantly more consistent in group 1 than in group 2 patients (P < 0.01). Among the patients who remained in treatment, 64.4% achieved early full substance abuse remission, whereas 35.6% achieved partial substance abuse remission, with a significant difference between 1 (78.13%) and 2 (46.1%) treatment subgroups (P = 0.04). Although obtained by an observational-open clinical study with multiple limitations, our findings suggest that OLA may be able to increase retention and negative urinalyses rates during opioid agonist maintenance treatment in the patients with SSD and to improve psychopathology symptoms and tolerability in these dually diagnosed heroin addicts. Preliminary accurate diagnostic assessment and appropriate psychoactive medication in addicted patients affected by schizophrenia and schizotypal and schizoaffective-bipolar disorders seem to obtain less adverse effects and a more successful outcome of drug dependence treatment.