What is the equivalent injectable form of Zyprexa (olanzapine) 10mg daily?

From the Guidelines

To convert from oral Zyprexa (olanzapine) 10 mg daily to an injectable form, the recommended equivalent would be Zyprexa Relprevv 210 mg every 2 weeks or 405 mg every 4 weeks. When considering this conversion, it's essential to prioritize the patient's morbidity, mortality, and quality of life. The most recent and highest quality study 1 provides guidance on the management of delirium symptoms, which can be a concern when switching to an injectable form of olanzapine. Before starting the long-acting injection, consider a test dose of 5-10 mg of immediate-release intramuscular olanzapine to assess tolerability, as recommended in the guidelines 1. Some key points to consider when initiating Zyprexa Relprevv include:

• Continue the oral olanzapine for the first 2 weeks to maintain therapeutic levels while the long-acting formulation reaches steady state.
• The injection must be administered in a healthcare facility with post-injection monitoring for at least 3 hours due to the risk of post-injection delirium/sedation syndrome.
• Monitor patients for common side effects including sedation, weight gain, and metabolic changes regardless of administration route. Alternatively, for acute situations, immediate-release olanzapine injection can be given at 5-10 mg doses as needed, but this is not a long-term replacement for daily oral therapy. It's also important to note that the study 1 from 2005 provides some general guidance on the use of antipsychotics, but the more recent study 1 takes precedence in terms of recommendations for injectable olanzapine. Overall, the conversion to an injectable form of olanzapine can be an effective way to improve adherence and maintain therapeutic levels, while minimizing the risk of side effects and prioritizing the patient's quality of life.

From the Research

Change from Oral to Injectable Olanzapine

To change from oral olanzapine 10 mg daily to an injectable form, several factors need to be considered, including the equivalent dose and the administration schedule.

• The injectable form of olanzapine is known as olanzapine pamoate or olanzapine long-acting injection (OLAI) 2.
• OLAI is administered every 2 or 4 weeks, and its efficacy has been demonstrated in clinical trials for the treatment of schizophrenia 2.
• The dose of OLAI is not directly equivalent to the oral dose, and the conversion should be done under the guidance of a healthcare professional.

Dosing Considerations

• The optimal therapeutic range of olanzapine serum levels is 20 to 40 ng/ml, and concentrations above 80 ng/ml may increase the risk of adverse events 3.
• High doses of olanzapine (>20 mg/day) may be more efficacious for some patients, but they also increase the risk of weight gain and other side effects 4, 5.
• The long-term safety and efficacy of olanzapine have been demonstrated in several studies, including a 4-year open-label study of olanzapine and samidorphan 6.

Administration and Monitoring

• OLAI is generally well-tolerated, but it can cause post-injection syndrome, which requires monitoring by healthcare professionals for at least 3 hours after administration 2.
• Patients receiving OLAI should be closely monitored for adverse events, including weight gain, changes in lipid and glycemic parameters, and other side effects 6.
• Therapeutic drug monitoring (TDM) may be useful in optimizing olanzapine therapy and minimizing the risk of side effects 3.