The effectiveness of antipsychotic medications in patients who use or avoid illicit substances: results from the CATIE study.
OBJECTIVE
This double-blind study compared a second generation (atypical) antipsychotic drugs compared to a representative older agent for patients with schizophrenia who use or avoid illicit substances.


METHODS
Schizophrenic subjects were recruited at 57 U.S. sites and randomly assigned to olanzapine, perphenazine, quetiapine, risperidone or ziprasidone for up to 18 months. The primary aim of this analysis was to delineate differences between the overall effectiveness of these five treatments among patients who used or did not use illicit substances.


RESULTS
There were no significant differences between treatment groups in time to all-cause treatment discontinuation among patients who use illicit drugs (median 3.3 to 6.8 months). Among non-users time to treatment discontinuation was significantly longer for patients treated with olanzapine (median 13.0 months) than perphenazine ( 5.9 months), risperidone (5.6 months), or quetiapine (5.0 months); time to discontinuation for ziprasidone (4.3 months) was even shorter, although the latter difference was not significant. The difference between risperidone and quetiapine, although small, was significant. All remaining differences were non-significant. Similar results were found for discontinuation due to inefficacy. There were no differences between illicit users and non-users in symptom reduction and global improvement, after adjustment for differential duration of treatment. Differences in discontinuation results were attenuated by non-compliance, but the trends persisted after controlling for treatment compliance.


CONCLUSIONS
Among patients with chronic schizophrenia who avoid use of illicit drugs, olanzapine was more effective than other antipsychotics as reflected by longer time to all-cause discontinuation, but illicit substance abuse attenuated this advantage, reinforcing the need for concurrent substance abuse treatment.
Swartz
Marvin S
MS
Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham NC 27710, United States. swart001@mc.duke.edu
Wagner
H Ryan
HR
Swanson
Jeffrey W
JW
Stroup
T Scott
TS
McEvoy
Joseph P
JP
Reimherr
Fred
F
Miller
Del D
DD
McGee
Mark
M
Khan
Ahsan
A
Canive
Jose M
JM
Davis
Sonia M
SM
Hsiao
John K
JK
Lieberman
Jeffrey A
JA
D000328:Adult; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000627:therapeutic use; D002908:Chronic Disease; D015897:Comorbidity; D003987:Dibenzothiazepines / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects*; D008297:Male; D000077152:Olanzapine; D010352:Patient Dropouts; D010546:Perphenazine / Q000627:therapeutic use; D000069348:Quetiapine Fumarate; D018967:Risperidone / Q000627:therapeutic use; D012559:Schizophrenia / Q000188:drug therapy* / Q000453:epidemiology; D012565:Schizophrenic Psychology; D019966:Substance-Related Disorders / Q000453:epidemiology* / Q000523:psychology; D013997:Time Factors; D016896:Treatment Outcome; D016312:Treatment Refusal
D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D013287:Illicit Drugs; D001569:Benzodiazepines; D000069348:Quetiapine Fumarate; D010546:Perphenazine; D018967:Risperidone; D000077152:Olanzapine