Olanzapine-Fluoxitine (Symbyax)
Second generation antipsychotic (dopamine, serotonin receptor antagonist (D2, 5-HT2)) with SSRI
- Treatment resistant depression
- May cause manic symptoms in bipolar
- Bipolar Depression
Features
Dosing
3/25 mg 1 qhs x7days then 6/25 mg 1 qhs; mean dose 7.4/39.3 mg hs
Management
Very effective for BP depression, but effect size actually smaller for unipolar treatment resistant depression. The fluoxetine can cause mixed/manic symptoms in bipolar, but olanzapine alone did not work much in bipolar depression.
TOLERABILITY: Weight gain, sedation, akathisia, EPS (dystonia, stiffness), anticholinergic.
Side effects fluoxetine: apathy, sexual dysfunction, restlessness, (also sleep disruption, nausea, but olanzapine counteracts these), osteopenia in post-menopausal women. Fluoxetine raises lots of drug levels by inhibiting CYP 2D6, 3A4, 2C9, 2C19, 2B6.
RISKS: Tardive dyskinesia (25% over 10 years, higher in elderly), metabolic, prolactinemia (can lead to breast cancer, osteopenia, sexual dysfunction), orthostasis (falls), QTc prolongation, temperature imbalance in elderly, NMS (muscle rigidity, fever, tachycardia).
EMR Text
Bipolar depression
Olanzapine-fluoxetine use based on FDA approval in bipolar depression.
Antipsychotic and SSRI side effects, including metabolic, prolactinemia, and TD, reviewed with patient.
Unipolar depression
Olanzapine-fluoxetine use based on FDA approval in treatment-resistant depression.
Antipsychotic and SSRI side effects, including metabolic, prolactinemia, and TD, reviewed with patient.