What is the dosing for Zyprexa (olanzapine)?

From the Guidelines

Olanzapine (Zyprexa) should be started at a dose of 2.5-5 mg once daily for adults, with a target dose range of 10-20 mg daily, as recommended by the most recent and highest quality study 1. The dosing of olanzapine can vary depending on the patient population and the specific condition being treated.

• For adults with schizophrenia or bipolar disorder, the typical starting dose is 2.5-5 mg once daily, with a target dose range of 10-20 mg daily.
• For elderly patients or those with hepatic impairment, a lower starting dose of 2.5 mg is recommended, with gradual titration as needed and tolerated.
• The medication can be taken with or without food, and the dose is usually adjusted gradually based on clinical response and tolerability. Some key points to consider when dosing olanzapine include:
• The risk of metabolic side effects, such as weight gain, hyperglycemia, and dyslipidemia, which should be monitored regularly.
• The potential for sedation and orthostatic hypotension, especially during initial treatment.
• The importance of gradual dose titration to minimize the risk of adverse effects. It's worth noting that the study from 2018 1 provides the most recent and highest quality evidence for the dosing of olanzapine, and should be prioritized over older studies such as those from 2002 1 and 2005 1.

From the FDA Drug Label

When indicated, dose escalation should be performed with caution in these patients Maintenance Treatment — The effectiveness of oral olanzapine, 10 mg/day to 20 mg/day, in maintaining treatment response in schizophrenic patients who had been stable on ZYPREXA for approximately 8 weeks and were then followed for relapse has been demonstrated in a placebo-controlled trial Adolescents Dose Selection — Oral olanzapine should be administered on a once-a-day schedule without regard to meals with a recommended starting dose of 2.5 or 5 mg, with a target dose of 10 mg/day. Adults Dose Selection for Monotherapy — Oral olanzapine should be administered on a once-a-day schedule without regard to meals, generally beginning with 10 or 15 mg. Dose Selection for Adjunctive Treatment — When administered as adjunctive treatment to lithium or valproate, oral olanzapine dosing should generally begin with 10 mg once-a-day without regard to meals The recommended dose in these patients is 10 mg. A lower dose of 5 or 7.5 mg may be considered when clinical factors warrant

The dosing for Zyprexa (olanzapine) is as follows:

• Schizophrenia:
  • Adults: 10 mg/day to 20 mg/day
  • Adolescents: starting dose of 2.5 or 5 mg, with a target dose of 10 mg/day
• Bipolar I Disorder (Manic or Mixed Episodes):
  • Adults: starting dose of 10 or 15 mg
  • Adolescents: starting dose of 2.5 or 5 mg, with a target dose of 10 mg/day
• Agitation Associated with Schizophrenia and Bipolar I Mania:
  • Adults: 10 mg intramuscularly, with a lower dose of 5 or 7.5 mg considered when clinical factors warrant 2

From the Research

Dosing for Zyprexa (Olanzapine)

• The dosing for Zyprexa (olanzapine) varies depending on the condition being treated and the individual patient's response to the medication 3, 4, 5, 6, 7.
• The typical dosage range for olanzapine is 5-20 mg per day, with a maximum recommended dose of 20 mg per day 5, 6, 7.
• However, some studies have shown that doses above 20 mg per day may be more efficacious for certain patients, particularly those with treatment-resistant schizophrenia or bipolar disorder 5.
• The optimal therapeutic range of olanzapine serum levels is 20 to 40 ng/ml, with concentrations above 80 ng/ml considered to be associated with an increased risk of adverse events 4.
• Dose adjustments may be necessary for patients with moderate renal or hepatic impairment, as well as for those who are taking other medications that may interact with olanzapine 4, 6.
• A combination of olanzapine and samidorphan (OLZ/SAM) has been shown to be effective for the treatment of schizophrenia and bipolar I disorder, with a dosage range of 5 to 20 mg OLZ to a 10-mg fixed dose of samidorphan 7.

Factors Affecting Dosing

• Individual factors such as gender and smoking status can affect the pharmacokinetics of olanzapine, but dosage adjustments are generally not necessary for these factors 6.
• However, dosage modification may be necessary for patients with a combination of factors associated with decreased oxidative metabolism, such as debilitated or elderly women who are nonsmokers 6.
• Other medications, such as fluvoxamine, can increase plasma concentrations of olanzapine, while inducers of CYP1A2, such as tobacco smoke and carbamazepine, can decrease olanzapine concentrations 4, 6.