There is limited high-quality randomized controlled trial (RCT) evidence specifically comparing Zyprexa (olanzapine) or Seroquel (quetiapine) for the treatment of stimulant-induced psychosis (SIP), including cocaine-induced psychosis. However, some RCTs and observational studies provide useful insights:
Olanzapine (Zyprexa)
- RCT Evidence:
- A 2022 meta-analysis of antipsychotic treatments for stimulant-induced psychosis included olanzapine and found it to be effective in reducing positive psychotic symptoms, often comparable to haloperidol but with a better side effect profile (less extrapyramidal symptoms) 11.
- A double-blind RCT comparing olanzapine vs. haloperidol in methamphetamine-induced psychosisfound that both were effective at reducing PANSS (Positive and Negative Syndrome Scale) scores, but olanzapine was associated with better tolerability 22.
- Another RCT in methamphetamine-induced psychosis compared olanzapine and risperidone, showing similar efficacy but better tolerability with olanzapine 33.
Quetiapine (Seroquel)
- RCT Evidence:
- A small RCT in methamphetamine-induced psychosis found that quetiapine was effective but tended to require higher doses to achieve symptom resolution 44.
- A retrospective study on cocaine-induced psychosis suggested that quetiapine may help reduce symptoms, but data is weaker compared to olanzapine or risperidone 55.
- Quetiapine has also been studied as an option for reducing cocaine cravings, but results are mixed and it is generally less preferred for acute agitation compared to faster-acting options like olanzapine.
Head-to-Head Comparison
There is no direct RCT comparing olanzapine vs. quetiapine for stimulant-induced psychosis, but based on available data:
- Olanzapine is generally preferred for acute agitation and psychosis because of its faster onset and greater D2 blockade.
- Quetiapine may be useful in milder cases or for individuals needing sedation, but higher doses are often required.
Clinical Implications
- For acute stimulant-induced psychosis, olanzapine (5–10 mg IM or PO) is a common first-line option due to rapid onset and favorable side effect profile.
- Quetiapine (200–400 mg PO) can be considered, particularly for patients needing sedation or those with comorbid conditions like bipolar disorder.
- Other antipsychotics with strong evidence include risperidone and haloperidol (though the latter has more extrapyramidal risk).
After reviewing the available literature, direct randomized controlled trials (RCTs) comparing olanzapine (Zyprexa) and quetiapine (Seroquel) for stimulant-induced psychosis (SIP), including cocaine-induced psychosis, remain scarce. However, some studies provide relevant insights:
Olanzapine (Zyprexa):
- Efficacy: A randomized, double-blind trial compared olanzapine and haloperidol in patients with amphetamine-induced psychosis. Both medications effectively improved psychotic symptoms in the short term, with olanzapine showing a faster onset of action.
Quetiapine (Seroquel):
- Efficacy: A double-blind RCT compared haloperidol and quetiapine for methamphetamine-induced psychosis. While both medications reduced psychotic symptoms, quetiapine appeared to have a more favorable profile in reducing certain symptoms over time.
Indirect Comparisons:
- First-Episode Psychosis: A 52-week randomized, double-blind study evaluated olanzapine, quetiapine, and risperidone in early psychosis patients. All three antipsychotics demonstrated comparable effectiveness, as indicated by similar rates of treatment discontinuation.
Conclusion:
While direct RCT evidence comparing olanzapine and quetiapine specifically for stimulant-induced psychosis is limited, existing studies suggest that both medications are effective in managing such conditions. Olanzapine may offer a faster onset of symptom relief, whereas quetiapine might present a more favorable side effect profile. Clinical decisions should be individualized, considering factors such as patient history, specific symptomatology, and potential side effects.
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