How to cross-taper from risperidone to olanzapine?

Cross-Tapering from Risperidone to Olanzapine

To cross-taper from risperidone (0.5mg AM and 0.75mg QHS) to olanzapine, discontinue the morning 0.5mg risperidone dose and start olanzapine 2.5mg daily, then gradually reduce the evening risperidone dose while increasing olanzapine to target dose over 1-2 weeks.

Initial Cross-Taper Strategy

• Discontinue the morning 0.5mg risperidone dose and start olanzapine 2.5mg daily 1
• Continue the evening 0.75mg risperidone dose for the first week 2
• After one week, reduce risperidone to 0.375mg (half the evening dose) while increasing olanzapine to 5mg daily 2, 3
• After another week, discontinue risperidone completely and increase olanzapine to 7.5-10mg daily (target dose) 1, 3

Rationale for This Approach

• Gradual cross-tapering over 2 weeks is associated with higher retention rates and fewer discontinuation symptoms compared to abrupt switching 2
• The initial target dose of olanzapine should be 7.5-10mg daily for most patients 1
• Starting with a lower dose of olanzapine (2.5mg) while maintaining partial risperidone coverage minimizes the risk of psychotic symptom exacerbation during transition 3
• A gradual withdrawal strategy is recommended when discontinuing antipsychotics to minimize potential discontinuation effects including dyskinesias, parkinsonian symptoms, and dystonias 1

Monitoring During Cross-Tapering

• Assess for extrapyramidal side effects during the transition, as these should be avoided to encourage future medication adherence 1
• Monitor for sedation, which may be more prominent with olanzapine compared to risperidone 1
• Evaluate sleep quality, as both medications can affect sleep patterns differently 1
• Watch for metabolic effects, particularly weight gain which may be more significant with olanzapine 1

Special Considerations

• If the patient experiences breakthrough symptoms during the cross-taper, consider slowing the risperidone taper by extending each step to 10-14 days 1, 2
• If sedation becomes problematic with olanzapine, consider administering the full dose at bedtime rather than in the morning 4
• For patients with difficulty tolerating the transition, the cross-taper period can be extended, as withdrawal should be gradual, in most cases extending over a period greater than one month for antipsychotics 1
• Once-daily dosing of olanzapine is preferred over twice-daily dosing due to comparable efficacy but potentially better side effect profile and adherence 4

Common Pitfalls to Avoid

• Avoid abrupt discontinuation of risperidone, which can lead to withdrawal symptoms and increased risk of relapse 1, 2
• Don't start with too high a dose of olanzapine (>10mg), as this increases the risk of side effects without proportional efficacy benefits 1
• Be cautious about drug interactions if the patient is on other psychotropic medications that might affect the metabolism of either medication 5
• Don't neglect to inform the patient about potential side effect differences between the medications, particularly regarding sedation and weight gain 1