Quetiapine: a pharmacoeconomic review of its use in bipolar disorder.
Author(s): Plosker GL.
Affiliation(s): Adis, Auckland, New Zealand. demail@adis.co.nz
Publication date & source: 2012, Pharmacoeconomics. , 30(7):611-31
This article briefly summarizes the burden of bipolar disorder and the clinical
profile of quetiapine (Seroquel®) in the management of bipolar disorder, followed
by a detailed review of pharmacoeconomic analyses. Quetiapine is an atypical
antipsychotic that is available in numerous countries as immediate-release and
extended-release tablets for the treatment of major psychiatric disorders,
including bipolar disorder. Randomized, double-blind, placebo-controlled trials
with quetiapine have demonstrated its efficacy in bipolar I and II disorders, and
the drug has been generally well tolerated in clinical trials. Three
cost-effectiveness analyses of maintenance therapy in bipolar I disorder, which
used similar Markov models and incorporated data from key clinical trials and a
number of other sources, showed that quetiapine, as adjunctive therapy with mood
stabilizers (lithium or divalproex), was a cost-effective treatment option from
the healthcare payer perspective in the UK and the US. Quetiapine either
dominated comparators (typically mood stabilizers alone) or was associated with
incremental cost-effectiveness ratios that were usually well below widely
accepted thresholds of cost effectiveness. One of the studies evaluated
extended-release quetiapine, although clinical efficacy data used in the Markov
model were for the immediate-release formulation. In another analysis, which used
a discrete-event simulation model and was conducted from the perspective of the
UK healthcare payer, quetiapine monotherapy was cost effective compared with
olanzapine monotherapy as maintenance treatment for all phases of bipolar I or II
disorder. In this model, favourable results were also shown for quetiapine (with
or without mood stabilizers) compared with a wide range of maintenance therapy
regimens. Another modelled analysis conducted from the UK healthcare payer
perspective showed that quetiapine was dominated by haloperidol in the short-term
treatment of a manic episode in patients with bipolar I disorder. Both favourable
and unfavourable results have been reported in cost analyses of quetiapine in
bipolar disorder (type I or type not specified). Possible explanations for some
of the variability in results of the pharmacoeconomic analyses include
heterogeneity among the models in terms of input parameters or assumptions in the
base-case analyses, country- or region-specific differences in estimates of
healthcare resource use and associated costs, variability in treatment
alternatives, and differences in the year of costing and discounting used in the
analyses. In addition, some of the studies had short time horizons and focused on
acute manic episodes only, whereas others were longer-term analyses that
considered the full spectrum of health states in patients with bipolar disorder.
Various limitations of the studies have been recognized, and results from one
country may not be applicable to other countries. In conclusion, results of
available pharmacoeconomic analyses provide evidence of the cost effectiveness of
quetiapine as an adjunct to mood stabilizers for maintenance therapy in
(primarily type I) bipolar disorder from a healthcare payer perspective in the UK
and the US. Some evidence is available to support the cost effectiveness of
quetiapine monotherapy or the use of extended-release quetiapine as adjunctive
therapy with mood stabilizers in this setting, although further analyses appear
to be warranted. Whether these findings apply to other geographical regions
requires further study. Evidence for the long-term (>2-year) cost effectiveness
of quetiapine in bipolar disorder is currently limited and further studies are
also needed to address the cost effectiveness of quetiapine from a societal
perspective and in bipolar II disorder.
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