Source: DGNews  |  Posted 4 years ago

By Alison Palkhivala

MONTREAL, CANADA -- November 21, 2007 -- Recent trials on the management of generalised anxiety disorder (GAD) provide an update on currently available guidelines regarding the best options for the management of this condition. These new trials highlight the efficacy of the antidepressants escitalopram and duloxetine as well as the anticonvulsants pregabalin and alprazolam.

According to the 2006 guidelines from the Canadian Anxiety Disorder, first-line options for GAD are escitalopram, paroxetine, sertraline, and venlafaxine XR. Since then, new data have become available that better clarifies the role of the antidepressants escitalopram, venlafaxine, and duloxetine as well as the anticonvulsants pregabalin and alprazolam in GAD.

Jacques Plamondon, MD, Psychiatrist and Clinical Associate Professor, University of Quebec Hospital Centre, Sainte-Foy, Quebec, Canada presented these findings here on November 17 at the 57th Annual Conference of the Canadian Psychiatric Association (CPA).

Among these findings are those of two studies comparing escitalopram directly with paroxetine, which demonstrated the superiority of escitalopram in the treatment of GAD. Specifically, the drug has been found to be superior to paroxetine with respect to overall efficacy as well as tolerability. "What was interesting is that escitalopram 10 mg was more effective than paroxetine 20 mg," said Dr. Plamondon during his presentation.

In these studies, escitalopram was also found to be superior to placebo with respect to reducing the risk of relapse in GAD for up to 18 months. "The risk of relapse was four times higher in the placebo group compared to the escitalopram group," said Dr. Plamondon. "That's a key message when your patient asks you, 'how long should I take this? What will happen if I stop treatment?' Well the answer is, your risk of relapse is four times higher."

With respect to venlafaxine XR and paroxetine, these two agents were compared directly against each other and were found to be similarly effective in the treatment of GAD.

A newer antidepressant, duloxetine, has also shown promise in GAD in recent trials with respect to improvements in patient functioning and anxiety levels. In a head-to-head trial, it has also been shown to be as effective as venlafaxine for this indication.

The anticonvulsant agent pregabalin has been shown to improve anxiety levels in patients with GAD better than placebo. In a head-to-head, placebo-controlled study venlafaxine and pregabalin were both shown to be effective for this indication.

Another anticonvulsant, alprazolam, has been shown to speed improvement in insomnia and global secondary outcome measures when combined with serotonin reuptake inhibitors (SRIs), when compared with SRI monotherapy.

Looking to the future, said Dr. Plamondon, pregabalin will be approved in an increasing number of countries for GAD in the coming years. Duloxetine, tiagabine, pagaclone, as well as investigational agents targeting glutamate and 5-HT_1A are all in phase 3 development for use in GAD.

[Presentation title: The Canadian Anxiety Disorders Treatment Guidelines Initiative: An Update on GAD and OCD. Abstract I04]