A random-assignment, double-blind, clinical trial of once- vs twice-daily administration of quetiapine fumarate in patients with schizophrenia or schizoaffective disorder: a pilot study.
OBJECTIVE
To evaluate the efficacy and safety of administering quetiapine once vs twice daily.


METHODS
Utilizing a double-blind design, 21 hospitalized adult men or women with DSM-IV schizophrenia or schizoaffective disorder, who had received unchanged doses (for 2 weeks) of either 400 or 600 mg daily of quetiapine administered in 2 doses, were randomly assigned to once- or twice-daily administration for 4 weeks and then crossed over to the opposite dosing regimen for an additional 4 weeks. Standard psychopathology and safety measures were used in the study.


RESULTS
Nearly 70% (15/21) of the subjects met the a priori efficacy responder criteria with no statistical differences in response between those assigned to once- or twice-daily quetiapine administration. Statistical analyses confirmed that most subjects maintained efficacy during the switch to once- or twice-daily administration with quetiapine. A minority (15%) did experience worsening of symptoms or orthostatic hypotension during the crossover. Quetiapine was generally well tolerated at either twice- or once-daily administration.


CONCLUSIONS
These pilot data suggest that it is clinically feasible to switch most quetiapine-treated subjects receiving a therapeutic twice-daily dosing schedule to a once-daily regimen. A minority may experience worsening of symptoms or orthostatic hypotension during the switch. This strategy of administering quetiapine entirely at bedtime may promote improved adherence to treatment.
Mayview State Hospital, 1601 Mayview Road, Bridgeville, PA 15017-1599, USA.
K N Roy
KN
Chengappa
Haranath
H
Parepally
Jaspreet S
JS
Brar
Jamie
J
Mullen
Ann
A
Shilling
Jeffrey M
JM
Goldstein
D000293:Adolescent; D000328:Adult; D000368:Aged; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D014150:Antipsychotic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D018592:Cross-Over Studies; D003987:Dibenzothiazepines / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005650:Fumarates / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000523:psychology; D000069348:Quetiapine Fumarate; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology
D016588:Anticarcinogenic Agents; D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D005650:Fumarates; D000069348:Quetiapine Fumarate; C032005:fumaric acid