Pediatric population: Interaction studies have only been performed in adults.
Potential Interactions Affecting Olanzapine: Since Olanzapine is metabolized by CYP1A2, substances that can specifically induce or inhibit this isoenzyme may affect the pharmacokinetics of Olanzapine.
Induction of CYP1A2: The metabolism of Olanzapine may be induced by smoking and carbamazepine, which may lead to reduced Olanzapine concentrations.
Inhibition of CYP1A2: Fluvoxamine, a specific CYP1A2 inhibitor, has been shown to significantly inhibit the metabolism of Olanzapine. The mean increase in Olanzapine Cmax following fluvoxamine was 54% in female non-smokers and 77% in male smokers. The mean increase in Olanzapine AUC was 52% and 108%, respectively.
Decreased bioavailability: Activated charcoal reduces the bioavailability of oral Olanzapine by 50 to 60% and should be taken at least 2 hours before or after Olanzapine.
Fluoxetine (a CYP2D6 inhibitor), single doses of antacid (aluminum, magnesium) or cimetidine have not been found to significantly affect the pharmacokinetics of Olanzapine.
Potential for Olanzapine to Affect Other Medicinal Products: Olanzapine may antagonize the effects of direct and indirect dopamine agonists.
Olanzapine does not inhibit the main CYP450 isoenzymes in vitro (e.g., 1A2, 2D6, 2C9, 2C19, 3A4).
General CNS activity: Caution should be exercised in patients who consume alcohol or receive medicinal products that can cause central nervous system depression.
Qtc interval: Caution should be used if Olanzapine is being administered concomitantly with medicinal products known to increase QTc interval.