Clinical trial response and dropout rates with olanzapine versus risperidone.
BACKGROUND
In schizophrenia, comparing treatment dropouts between olanzapine and risperidone can be useful to better understand their relative effectiveness.


OBJECTIVE
To analyze the differences in the rates of dropout from clinical trials and response between these 2 antipsychotics.


METHODS
Literature search was based on MEDLINE (1966-May 2002). Analysis 1 included 4 randomized studies (838 patients), analysis 2 included 2 randomized studies (n = 716), and analysis 3 assessed 5 clinical studies for olanzapine (n = 928) and 3 for risperidone (n = 290). Odds ratios were estimated by the fixed-effect model.


RESULTS
The risk of treatment discontinuation (analysis 1) was significantly greater for risperidone than for olanzapine (42% vs. 33%, respectively). The response rates were identical for the 2 drugs (analysis 2). A slightly better pattern of maintenance of response was found for olanzapine (analysis 3).


CONCLUSIONS
The pattern of dropout and maintenance of remission seems to be better controlled for olanzapine than for risperidone.
Santarlasci
Benedetta
B
Pharmacoeconomic Laboratory, Italian Society of Hospital Pharmacists, Careggi Hospital, Florence, Italy.
Messori
Andrea
A
D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001569:Benzodiazepines; D005260:Female; D006801:Humans; D008297:Male; D000077152:Olanzapine; D010349:Patient Compliance / Q000706:statistics & numerical data*; D010352:Patient Dropouts / Q000706:statistics & numerical data*; D010890:Pirenzepine / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D018967:Risperidone / Q000009:adverse effects / Q000627:therapeutic use*; D012559:Schizophrenia / Q000188:drug therapy; D013997:Time Factors; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D001569:Benzodiazepines; D010890:Pirenzepine; D018967:Risperidone; D000077152:Olanzapine