Treatment-resistant schizophrenic patients respond to clozapine after olanzapine non-response.
BACKGROUND
Treatment-resistance in schizophrenia remains a public health problem. Clozapine has been shown to be effective in about one third of this population, but carries with it medical risks and weekly blood draws. As olanzapine is a drug with a very similar biochemical profile to clozapine, it is important to evaluate whether non-response to olanzapine predicts clozapine non-response.


METHODS
Forty-four treatment-resistant patients received eight weeks of olanzapine, either in a double-blind trial or subsequent open treatment at a mean daily dose of 25 mg/day. Two of 44 patients (5%) responded to olanzapine treatment. Patients who did not respond could then receive clozapine. Twenty-seven subsequently received an 8-week open trial of clozapine.


RESULTS
Patients who did and did not receive clozapine did not differ demographically or in psychopathology. Eleven of 27 (41%) met a priori response criteria during clozapine treatment (mean dose 693 mg/day) after failing to respond to olanzapine.


CONCLUSIONS
This study demonstrates that failure to respond to olanzapine treatment does not predict failure to clozapine. Treatment-resistant patients who fail on olanzapine may benefit from a subsequent trial of clozapine.
Conley
R R
RR
Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore 21228, USA.
Tamminga
C A
CA
Kelly
D L
DL
Richardson
C M
CM
D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001569:Benzodiazepines; D003024:Clozapine / Q000627:therapeutic use*; D004311:Double-Blind Method; D004351:Drug Resistance; D005260:Female; D006801:Humans; D008297:Male; D000077152:Olanzapine; D010890:Pirenzepine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D012559:Schizophrenia / Q000188:drug therapy*; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D001569:Benzodiazepines; D010890:Pirenzepine; D003024:Clozapine; D000077152:Olanzapine