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.
Chengappa
K N Roy
KN
Mayview State Hospital, 1601 Mayview Road, Bridgeville, PA 15017-1599, USA.
Parepally
Haranath
H
Brar
Jaspreet S
JS
Mullen
Jamie
J
Shilling
Ann
A
Goldstein
Jeffrey M
JM
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