Posted by ed_uk on February 3, 2005, at 7:44:56
In reply to Re: SEROQUEL, posted by yxibow on February 2, 2005, at 17:20:53
Thanks for the link :-)
I'd generally still suggest taking it twice daily when used for psychosis- it's short half-life suggests that taking it once daily might lead to large fluctuations in the plasma concentration over 24h. Taking the whole dose at night might be optimal for some people though, esp. if it was effective in minimizing day-time drowsiness and/or improving compliance, YMMV!
Here is an interesting study- it's a small study though so I think it would be best to treat its conclusion with caution......
Can J Psychiatry. 2003 Apr;48(3):187-94.
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.
Chengappa KN, Parepally H, Brar JS, Mullen J, Shilling A, Goldstein JM.
Mayview State Hospital, 1601 Mayview Road, Bridgeville, PA 15017-1599, USA.
OBJECTIVE: To evaluate the efficacy and safety of administering quetiapine once vs twice daily. METHOD: 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.