Olanzapine/fluoxetine: a review of its use in patients with treatment-resistant major depressive disorder.

Olanzapine/fluoxetine (Symbyax) is an oral, once-daily, fixed-dose combination of the atypical antipsychotic olanzapine and the selective serotonin reuptake inhibitor (SSRI) fluoxetine. It is indicated, in adult patients, for the acute treatment of depressive episodes associated with bipolar I disorder and treatment-resistant major depressive disorder. In adult patients with treatment-resistant depression (major depressive disorder in adults who do not respond to two separate trials of different antidepressants of adequate dose and duration in the current episode), olanzapine plus fluoxetine combination therapy was generally more effective than either drug as monotherapy based on an integrated analysis of clinical trials of 8-12 weeks' duration. More limited data also indicate that longer-term treatment for 76 weeks with olanzapine plus fluoxetine was efficacious in this patient group. Combination therapy was generally well tolerated, with a tolerability profile similar to that of olanzapine monotherapy, although fluoxetine monotherapy was generally better tolerated than olanzapine plus fluoxetine. The combination of olanzapine plus fluoxetine, as a fixed-dose formulation, offers a useful treatment option in this difficult-to-treat patient group.