Quetiapine in the treatment of acute mania: target dose for efficacious treatment

Abstract

Objective: To analyze the available evidence from randomized clinical trials regarding the effective dose range and optimal dose of quetiapine when treating bipolar I disorder patients with acute mania.

Methods: Patients with acute mania were treated with quetiapine as monotherapy (for 12 weeks) or in combination with lithium (mean serum concentration 0.76 mEq/L) or divalproex (mean serum concentration 69.5 microg/mL) (Li/DVP) (for 3-6 weeks) in four double-blind, placebo-controlled studies according to a predetermined dosing schedule. Guidance for the dosing of quetiapine involved increasing the first day's dose (100 mg/day) by 100 mg on a daily basis until Day 4 (400 mg/day), then adjusting the dose up to 600 mg/day at Day 5, and up to 800 mg/day thereafter. Pooled data from the two monotherapy studies and the two combination therapy studies have been used to evaluate the effective quetiapine dose range. As the dose was flexible, effective dose was estimated by the mean last-week dose among responders. The mean last-week dose was defined as the median dose during the 7 days before the last available Young Mania Rating Scale (YMRS) assessment. Patients who achieved a > or = 50% decrease in the YMRS total score from baseline to end of treatment with quetiapine were considered responders. Tolerability was assessed from direct patient reports.

Results: According to randomized clinical trials, administration of quetiapine compared with placebo achieved a statistically significant improvement in change from baseline YMRS score within the first week and onward, as monotherapy or in combination with Li/DVP. The average quetiapine dose (+/-SD) in responders during the last week of treatment was 575 (+/-175) at Day 21 and 598 (+/-198) mg/day at Day 84 for monotherapy, and 584+/-208 mg/day at Day 21 for combination therapy, with most responders receiving doses within the range of 400-800 mg/day. Dose escalation was rapid, with 92% of patients treated with monotherapy and 80% of patients treated with combination therapy reaching doses of 400 mg/day by Day 4, in accordance with protocol-defined dosing guidance. This dose administration schedule was generally well tolerated.

Conclusions: The mean last-week median dose among responders suggests that 600 mg/day of quetiapine is an effective target dose in acute mania.