Dose–response relationship of duloxetine in placebo-controlled clinical trials in patients with major depressive disorder
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- Bech, P., Kajdasz, D.K. & Porsdal, V. Psychopharmacology (2006) 188: 273. doi:10.1007/s00213-006-0505-1
The optimal dose for achieving the maximum antidepressive effect of selective serotonin reuptake inhibitors (SSRIs) or serotonin-noradrenalin reuptake inhibitors (SNRIs) remains a controversial issue. The varying sensitivity of scales that measure the severity of depression is one of the many factors affecting the evaluation of the dose–response relationship with antidepressants.
To determine if the 6-item Hamilton rating scale for depression (HAM-D6) demonstrates a clearer association between dose and antidepressive effect compared with the 17-item Hamilton rating scale for depression (HAM-D17) for fixed doses of duloxetine hydrochloride (40, 60, 80, and 120 mg daily) from six double-blind, randomized, placebo-controlled clinical trials assessing safety and efficacy in the acute treatment of patients with DSM-IV-defined major depressive disorder (MDD).
Mantel–Haenszel adjusted effect sizes were determined by dose for change from baseline to endpoint in HAM-D6 and HAM-D17 scores from the six studies. To confirm, assessments were repeated on the subset of the population corresponding to the 70% of patients with the longest duration of treatment regardless of study, treatment, dose, geography, or completion status.
For the majority of assessments, HAM-D6 effect sizes were numerically larger than those estimated from the HAM-D17. Findings support that duloxetine 60 mg daily is the best effective dose.
In this assessment of patients with MDD, the HAM-D6 was shown to be more sensitive compared with the HAM-D17 at detecting treatment effects. These findings are consistent with published results of other effective antidepressants.