What is the use of Olanzapine (atypical antipsychotic)?

From the Guidelines

Olanzapine should be started at a dose of 2.5-5 mg per day, with adjustments made based on response and tolerability, to minimize the risk of adverse effects such as drowsiness, orthostatic hypotension, and metabolic changes. According to the most recent and highest quality study available, which is the 2018 ESMO clinical practice guidelines for delirium in adult cancer patients 1, olanzapine is a second-generation antipsychotic that may have a role in the management of delirium symptoms. The guidelines suggest that olanzapine can be started at a dose of 2.5-5 mg per day, with a reduction in dose recommended for older patients and those with hepatic impairment.

Some key points to consider when prescribing olanzapine include:

• The medication can cause drowsiness, so it is recommended to take it at bedtime to minimize daytime sedation
• Olanzapine can also cause orthostatic hypotension, so patients should be monitored for this side effect
• Metabolic changes, such as elevated blood glucose and lipid levels, are also possible, so regular monitoring of these parameters is essential
• The medication should not be stopped abruptly, as this can cause withdrawal symptoms or symptom recurrence
• Patients should be patient when starting treatment, as the full therapeutic effect may take several weeks to reach

It is also important to note that olanzapine is not the only medication that can be used to treat delirium or other conditions, and other options may be available depending on the specific patient and their needs. However, based on the available evidence, olanzapine appears to be a reasonable option for some patients, and its use should be guided by the most recent and highest quality clinical guidelines available.

From the FDA Drug Label

ZYPREXA® (olanzapine) is an atypical antipsychotic indicated: As oral formulation for the: Treatment of schizophrenia. (1.1) Adults: Efficacy was established in three clinical trials in patients with schizophrenia: two 6-week trials and one maintenance trial. (14. 1) Adolescents (ages 13-17): Efficacy was established in one 6-week trial in patients with schizophrenia (14.1).

The primary use of Olanzapine is for the treatment of schizophrenia in adults and adolescents, as well as for the treatment of bipolar I disorder. The dosage and administration vary depending on the condition being treated and the age of the patient. Key points include:

• Schizophrenia in adults: start at 5-10 mg once daily, target 10 mg/day
• Schizophrenia in adolescents: start at 2.5-5 mg once daily, target 10 mg/day
• Bipolar I Disorder: start at 10 or 15 mg once daily for adults, and 2.5-5 mg once daily for adolescents 2

From the Research

Efficacy of Olanzapine

• Olanzapine has proven efficacy against the positive and negative symptoms of schizophrenia, with greater affinity for serotonin 5-HT2A than for dopamine D2 receptors 3.
• Compared to conventional antipsychotics, olanzapine has been shown to be significantly superior in overall improvements in psychopathology rating scales and in the treatment of depressive and negative symptoms 3.
• Olanzapine has also been found to be effective in the treatment of bipolar I disorder, with a combination of olanzapine and samidorphan (OLZ/SAM) providing similar symptom improvements to olanzapine alone, while mitigating olanzapine-associated weight gain 4.

Comparison to Other Antipsychotics

• Olanzapine has been compared to risperidone in several studies, with results showing that olanzapine is significantly more effective in the treatment of negative and depressive symptoms, but not in overall psychopathology symptoms 3.
• A study comparing the effectiveness of different dosing regimens of risperidone and olanzapine found that once-daily dosing was associated with lower mean daily doses and fewer side effects, particularly in patients receiving olanzapine 5.
• Olanzapine has also been compared to quetiapine, with factors such as mania, psychosis, and inpatient treatment being associated with the initiation of these second-generation antipsychotics 6.

Safety and Tolerability

• Olanzapine is associated with significantly fewer extrapyramidal symptoms than haloperidol and risperidone, but is associated with a higher risk of weight gain and metabolic effects 3, 4.
• The combination of olanzapine and samidorphan (OLZ/SAM) has been shown to mitigate olanzapine-associated weight gain, while maintaining similar efficacy and safety profiles to olanzapine alone 4.
• Olanzapine has been found to be safe and well-tolerated for up to 3.5 years of treatment, with a similar safety profile to that of olanzapine, except for less weight gain 4.