A non-inferiority comparison of duloxetine and venlafaxine in the treatment of adult patients with generalized anxiety disorder

Abstract

The present study is a non-inferiority comparison of duloxetine 60-120 mg/day and venlafaxine extended-release (XR) 75-225 mg/day for the treatment of adults with generalized anxiety disorder (GAD). The non-inferiority test was a prespecified plan to pool data from two nearly identical 10-week, multicentre, randomized, placebo-controlled, double-blind studies of duloxetine 60-120 mg/day and venlafaxine 75-225 mg/ day for the treatment of GAD. An independent expert consensus panel provided six statistical and clinical criteria for determining non-inferiority between treatments. Response was defined as > or =50% reduction in Hamilton Anxiety Rating Scale (HAMA) total score. In the pooled sample, patients were randomly assigned to duloxetine (n = 320), venlafaxine XR (n = 333) or placebo (n = 331). For the non-inferiority analysis, the per-protocol patients who were treated with duloxetine (n = 239) or venlafaxine XR (n = 262) improved significantly more (mean HAMA reductions were -15.4 and -15.2, respectively) than placebo-treated patients (n = 267; -11.6, P < or = 0.001, both comparisons). Response rates were 56%, 58% and 40%, respectively. Discontinuation rate because of AEs was significantly higher for duloxetine (13.4%, P < or = 0.001) and venlafaxine XR (11.4%, P < or = 0.01) groups compared with placebo (5.4%). Duloxetine 60-120 mg/day met all statistical and clinical criteria for non-inferiority and exhibited a similar tolerability profile compared with venlafaxine XR 75-225 mg/day for the treatment of adults with GAD.

An open, non‐randomised comparison of escitalopram and duloxetine for the treatment of subjects with Generalized Anxiety Disorder

“…Illness duration does not seem to affect the patients' recovery, whereas the presence of a Cluster C personality disorder apparently reduces the effectiveness of both medication treatments. These data seems to confirm the effectiveness of both medications as first-line treatments in GAD (Davidson, 2009), for the treatment of anxiety and depressive symptomatology (de Berardis et al, 2008;Pigott et al, 2007), as well as in terms of better psychosocial functioning of GAD patients (Allgulander et al, 2008).…”

“…For these reasons, greater interest has arisen in recent years for the so-called ''dual acting'' antidepressants or SNRIs (venlafaxine, duloxetine, milnacipran) and mirtazapine (Gambi et al, 2005). According to recent non-inferiority trials the effectiveness of duloxetine is equivalent to that of venlafaxine (Allgulander et al, 2008;Davidson, 2009;Hartford et al, 2007) in the treatment of GAD.…”

Therapeutic Effectiveness of Galphimia glauca vs. Lorazepam in Generalized Anxiety Disorder. A Controlled 15-Week Clinical Trial

“…This reduction is greater than that obtained in other clinical assays which administered different anxiolytics for 10 weeks, such as Lavandula sp. (an herbal product), duloxetine (an SNRI), venlafaxine (an SNRI), or citalopram (an SSRI), achieving a HAM-A scale reduction of between 13 and 15 points (56-59 %) [9,28,29]. Another interesting finding is that the greatest effect of the herbal product is observed with the Hamilton psychological anxiety subscale because, on comparing this effect with that of the somatic anxiety subscale, we observed significant differences from week 6 of administration.…”

Canadian clinical practice guidelines for the management of anxiety, posttraumatic stress and obsessive-compulsive disorders

“…Antidepressants ( SSRIs & SNRIs ) : Evidence from RCTs supports the use of SSRIs including escitalopram [544-552] and sertraline [556,559-561], as well as the SNRIs duloxetine [566-571] and venlafaxine XR [548,553,570-580] (all Level 1) for the first-line treatment of GAD. Similar evidence exists for paroxetine [546,547,553-558] supporting its use as a first-line option.…”