Atypical antipsychotics may help refractory depression

The use of atypical antipsychotics in patients with major depressive disorder (MDD) who have not responded to antidepressant therapy substantially increased clinical response rates at 6 weeks; however the drugs are also much more costly, according to the results of an analysis published in the May issue of The Annals of Pharmacotherapy.

“Major depressive disorder is a chronic and debilitating disease that affects approximately 13-14 million adults in the United States in any given year,” noted lead author Charu Taneja, MPH, senior research associate, Policy Analysis, Inc., Brookline, Mass.,  and colleagues.  “Despite the availability of various antidepressants with established efficacy, up to 50% of patients with MDD fail to respond fully to antidepressant therapy of adequate dose and duration. Patients with inadequate response to antidepressant therapy have significantly higher costs of care.”

In addition, clinical trials of these drugs provide evidence of their clinical utility, but they do not address their comparative cost-effectiveness, the authors wrote.

As a result, the researchers sought to address this knowledge gap by conducting a decision analysis based on data from phase 3 clinical trials. They estimated expected outcomes and costs for patients with MDD who were receiving:

Aripiprazole 2 mg to 20 mg/day plus antidepressant therapy.

Quetiapine 150 mg/day or 300 mg/day plus antidepressant therapy,

A fixed-dose combination of olanzapine 6, 12, or 18 mg/day with fluoxetine 50 mg/day.

Antidepressant therapy alone.

The primary outcome of interest was clinical response at 6 weeks, at which point patients were assumed either responders or nonresponders.

Results of their analysis indicated that antidepressant monotherapy was estimated to increase clinical response rate by 30% at 6 weeks with an estimated cost of $192.

Adjunctive therapy was estimated to increase clinical response to 49% with aripiprazole (estimated cost $847), 34% with quetiapine 150 mg/day (estimated cost $541), 38% with quetiapine 300 mg/day (estimated cost $672), and 45% with olanzapine/fluoxetine (estimated cost $791).

Estimated costs per additional responder over a 6-week period (versus antidepressant therapy) were:

$3,447 for aripiprazole.

$8,725 for quetiapine 150 mg/day.

$6,000 for quetiapine 300 mg/day.

$3,993 for olanzapine/fluoxetine.

Although the authors noted a higher clinical response for aripiprazole, the cost of MDD-related care was also higher.

The short time frame of the study was a limitation, the authors noted, because patients considered nonresponders at 6 weeks may continue therapy to eventually achieve response and likewise, those who respond may continue adjunctive therapy longer-term.

Therefore, they concluded that although the results indicate a higher response rate with antipsychotics and a lower cost-per-additional responder for aripiprazole adjunctive therapy, further research is needed to examine the cost-effectiveness of adjunctive therapy over time and should focus on remission as a measure of effectiveness.