Olanzapine is an atypical antipsychotic used for schizophrenia, bipolar disorder, and treatment-resistant depression (combined with fluoxetine).
Also known as: olanzapine, zyprexa
CYP inhibitor + antipsychotic: fluconazole may increase olanzapine levels.
Olanzapine is mainly metabolised by CYP1A2 and UGT. Fluconazole weakly inhibits CYP1A2. The effect on olanzapine levels is generally minimal (<20%). No routine dose adjustment required. Monitor for extrapyramidal effects if the patient is sensitive.
CYP1A2 inhibitor + antipsychotic: fluconazole may slightly increase olanzapine levels. Effect generally minimal.
Fluconazole inhibits CYP3A4, one of the metabolic pathways for olanzapine. The effect is moderate.
Sedation, EPS, metabolic syndrome signs.
Excessive sedation, severe EPS.
Monitor for sedation and extrapyramidal effects.
DailyMed/FDA
Mood stabiliser + antipsychotic: additive effect on manic symptoms.
The combination is used therapeutically in acute mania. Olanzapine may cause metabolic syndrome (weight gain, dyslipidaemia, hyperglycaemia), and lithium may add weight gain. Monitor weight, blood glucose, lipid profile, and EPS. Maintain lithium levels within therapeutic range. Consider metformin if metabolic syndrome develops.
Mood stabiliser + antipsychotic: additive effect on manic symptoms. Increased risk of metabolic syndrome.
The combination is used therapeutically in acute mania. Increased risk of metabolic syndrome and EPS.
Metabolic syndrome, EPS.
Severe metabolic syndrome.
Monitor weight, blood glucose, lipid profile and EPS.
DailyMed/FDA
No documented food or drink interactions.
No documented disease interactions.
No documented pregnancy or breastfeeding information.
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Multi-receptor antagonist (D2, 5-HT2A, H1, M1, α1). Antipsychotic and sedative effect.
Mesolimbic and cortical D2 antagonism. H1 antagonism contributes to sedation and weight gain. M1 antagonism for anticholinergic effects.
Good oral absorption. Bioavailability: 60%. Peak: 5-8 h.
Metabolised by CYP1A2 (major) and UGT. Smokers have 40% higher clearance.
21-54 h (mean: 30 h).
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
