Risk of extrapyramidal syndromes with haloperidol, risperidone, or olanzapine

Area of Science:

• Pharmacology
• Clinical Psychiatry
• Drug Safety

Background:

• Antipsychotic medications like risperidone, olanzapine, and haloperidol are used to treat various psychiatric conditions.
• Extrapyramidal syndrome (EPS) is a common side effect associated with these drugs, impacting patient adherence and quality of life.
• Understanding comparative EPS risk based on patient history is crucial for informed prescribing.

Purpose of the Study:

• To compare the incidence of extrapyramidal syndrome (EPS) among first-time users of risperidone, olanzapine, and haloperidol.
• To evaluate the influence of prior antipsychotic and antiparkinsonian drug use on EPS risk across these medications.
• To assess the risk of EPS in patients with a history of EPS.

Main Methods:

• Retrospective cohort study using the PHARMO-database (Netherlands, 1986-1999).
• Inclusion of 450,000 community-dwelling individuals, focusing on first-time users aged 15-54.
• EPS defined as first use of antiparkinsonian agents within 90 days; relative risks estimated using Cox models, stratified by treatment history.

Main Results:

• Identified cohorts: 424 haloperidol, 243 risperidone, 181 olanzapine users.
• Prior antipsychotic/antiparkinsonian use was significantly higher in risperidone and olanzapine groups (36.2%, 40.3%) vs. haloperidol (4.5%).
• Risperidone and olanzapine generally showed reduced EPS risk (RR 0.03-0.22) compared to haloperidol, except for risperidone users with prior EPS (RR 1.30).

Conclusions:

• Risperidone and olanzapine appear to have a lower risk of EPS than haloperidol in patients with similar treatment histories.
• The benefit of risperidone in patients with a previous history of EPS requires further investigation.
• Comparative effectiveness and safety profiles are essential considerations in antipsychotic selection.