From the Research
The safest way to transition from Seroquel (quetiapine) to olanzapine involves a gradual cross-titration approach under close medical supervision, as recommended by the most recent and highest quality study available 1. Begin by adding olanzapine at a low dose (typically 5-10 mg daily) while maintaining the current Seroquel regimen. After 3-7 days of dual therapy, gradually reduce the Seroquel dose by approximately 25-33% of the original dose every 5-7 days while simultaneously increasing the olanzapine dose as needed (typically to 10-20 mg daily, depending on clinical response). This gradual transition usually takes 2-4 weeks to complete. During this period, monitor closely for withdrawal symptoms from Seroquel, potential side effects from olanzapine, and changes in psychiatric symptoms. The overlap period helps prevent symptom rebound or withdrawal effects while allowing the new medication to reach therapeutic levels. This approach minimizes risks because both medications affect similar neurotransmitter systems (particularly dopamine and serotonin), but have different receptor binding profiles and potential side effects. Some key points to consider during the transition process include:
- Monitoring for metabolic changes, as both Seroquel and olanzapine can affect metabolic parameters 2, 3
- Watching for sedation levels, as both medications can cause sedation, especially during the initial phases of treatment 2, 3
- Assessing for extrapyramidal symptoms, which can occur with the use of antipsychotic medications like olanzapine 4, 2
- Considering the potential for weight gain, which is a common side effect of both Seroquel and olanzapine 2, 3
- Being aware of the potential for other side effects, such as increased sleep hours, drowsiness, and menstrual irregularities in women 2 The study by 1 provides the most recent and highest quality evidence for the transition process, and its recommendations should be prioritized in clinical practice. Additionally, the study by 2 provides valuable information on the efficacy and tolerability of olanzapine, quetiapine, and risperidone in the treatment of early psychosis, which can inform the transition process. However, the primary focus should be on the gradual cross-titration approach recommended by 1, as it is the most recent and highest quality study available.