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>>STOCKHOLM, Sweden, July 2 /PRNewswire/ -- A new study published in the British Journal of Psychiatry demonstrates that venlafaxine extended-release, a novel antidepressant that exhibits dual reuptake inhibition, provides successful long-term treatment of generalized anxiety disorder (GAD). The study evaluated the medication's efficacy in the treatment of GAD for up to six months(1). The findings support previous research, including a landmark June 2000 JAMA study(2), that showed venlafaxine extended-release provided significant improvements in symptoms of GAD for up to six months(3,4).
``Because the symptoms of GAD are so severe and incapacitating and take a much larger toll than everyday anxiety, long-term treatment may optimize a person's chances of not only controlling their symptoms, but achieving the optimal goal of treatment -- remission -- the virtual elimination of symptoms,'' said Christer Allgulander, M.D., Associate Professor of Psychiatry at Karolinska Institutet in Stockholm, Sweden, and lead investigator. ``This study shows that venlafaxine extended-release is effective for use over the long term, giving patients the best chance to return to their normal range of functioning.''
GAD, which affects an estimated 183 million people worldwide(5), is a chronic, debilitating condition marked by overwhelming and excessive worry, anxiety, and tension that persist for at least six months(6). However, for some, the condition can last for years. In fact, on average, patients in the study had been suffering from GAD for as long as 10 years.
Venlafaxine extended-release works simultaneously on the neurotransmitters serotonin and norepinephrine, two of the neurotransmitters implicated in depression and anxiety(7,8). It is believed serotonin enhances mood, thus affecting, for example, impulse, appetite, and feelings of aggression. Norepinephrine affects motivation.
Efficacy maintained for up to six months
The 24-week, placebo-controlled, double-blind study evaluated three fixed doses of venlafaxine extended-release (37.5 mg, 75 mg, and 150 mg). The primary outcome measure -- efficacy of each dose compared to placebo at week 24 -- was determined by the Hamilton Rating Scale for Anxiety (HRSA) total, HRSA psychic anxiety factor, Hospital Anxiety and Depression (HAD) anxiety sub-scale, and the Clinical Global Impression -- Improvement (CGI-I) rating. HRSA is a widely used and accepted outcome measure to evaluate anxiety, with 14 items each rated on a 5-point scale, ranging from 0 (anxiety not present) to 4 (severe anxiety).
At six months of treatment, patients taking venlafaxine extended-release (75 mg or 150 mg) showed significant differences in mean change on HRSA total score from baseline(9). Specifically, patients on venlafaxine extended-release 75 mg showed a mean change of 15.5 and patients on venlafaxine extended-release 150 mg showed a mean change of 16.4, compared with a mean change of 11.0 for patients on placebo (p<0.001). In addition, patients reported on the Self-Rated Social Adjustment Scale that their social functioning had improved at six months of treatment with venlafaxine extended-release.
The findings also showed that venlafaxine extended-release (37.5 mg, 75 mg, and 150 mg) is effective by the second week of treatment, compared to placebo (p?0.05)(10). ``Other pharmacologic treatment options, such as the benzodiazepines, bring quick symptom relief but are associated with side effects and potential dependence, which may hinder compliance,'' said Dr. Allgulander. ``Other antidepressant treatments for GAD, including the selective serotonin reuptake inhibitor (SSRI) paroxetine, have demonstrated only short-term (up to eight weeks) improvement in symptoms. Venlafaxine extended-release is backed by extensive efficacy and safety research, as well as widespread therapeutic use, that demonstrate it can sustain treatment in patients with GAD over the long term.''
About GAD
GAD is the most common anxiety disorder in primary care and the second most frequent mental disorder(11). Unlike normal, transient anxiety, the key characteristic of GAD is patients' loss of control over their worrying(12). The worry also typically persists for months and years, resulting in sleeplessness, irritability, poor concentration, and hypervigilence(13). The worry and anxiety associated with GAD are so intense they may impair sufferers in virtually all social roles, from relationships to occupational functioning(14). GAD often worsens and exacerbates co-existing health conditions, leading to further distress, disability, and demoralization, as well as depression(15). In fact, GAD often is associated with chronic depression, other anxiety disorders, and a wide range of medical conditions(16). Due to the chronic nature of the disorder and its negative impact on overall health, GAD is gaining recognition as a serious disorder in its own right, spurring the need for accurate diagnosis and effective treatment, as well as increased public outreach.
About the study
This study, ``Venlafaxine extended release (ER) in the treatment of generalised anxiety disorder: twenty-four-week placebo-controlled dose-ranging study,'' involved 541 patients from 55 European sites who had been diagnosed with GAD using DSM-IV criteria. Short-term efficacy was measured at eight weeks, and long-term efficacy was measured at 24 weeks (six months). There was no difference between venlafaxine extended-release and placebo in terms of the number of patients who dropped out of the study due to adverse events.
About Karolinska Institutet
Karolinska Institutet was founded in 1810 when army surgeons working among wounded soldiers needed training. Today it is a modern medical university with resources exceeding those of the battlefield.
Karolinska Institutet was founded in 1810 on the initiative of King Charles XIII after the defeat in the Finnish war against Russia of 1808 - 1809. At that time one third of the wounded died in field hospitals. The army surgeon's medical knowledge was obviously insufficient.
References
(1) Allgulander C, Hackett D, Salinas E. Venlafaxine Extended-Release
(ER) in the Treatment of Generalized Anxiety Disorder. Study
Abstract.
(2) Gelenberg A, et al. Efficacy of Venlafaxine Extended-Release Capsules
in Nondepressed Outpatients With Generalized Anxiety Disorder: A
6-Month Randomized Controlled Trial. Journal of the American Medical
Association, 283;23.
(3) Haskins JT, Rudolph R, Aguiar L, et al. Venlafaxine XR (V-XR) is an
Efficacious Short- and Long-Term Treatment for Generalized Anxiety
Disorder. Study Abstract.
(4) Hackett D, Parks V, Salinas E. A 6-Month Evaluation of 3 Dose Levels
of Velafaxine Extended-Release in Non-Depressed Outpatients with
Generalized Anxiety Disorder. Study Abstract.
(5) Figure calculated from data from International Programs Center, U.S.
Bureau of the Census (total population of the world projection
[6,100,401,574]) and generalized anxiety disorder prevalence data from
"Epidemiology of Generalized Anxiety Disorder" abstract, HU Wittchen
et al, Max Planck Institute of Psychiatry, 2000.
(Approx. 3 percent of worldwide population suffers from 12-month
generalized anxiety disorder).
(6) Venlafaxine XR Primary Data for Generalized Anxiety Disorder Executive
Summary. Wyeth-Ayerst data, 2000.
(7) Dubovsky SL. Beyond the serotonin reuptake inhibitors: rationales for
the development of new serotonergic agents. J Clin Psych, 1994; 55:2
(suppl).
(8) Brunello N, Racagni G. Rationale for the development of noradrenaline
reuptake inhibitors. Human Psychopharmacology, 1998; 13, S13-S19.
(9) Allgulander C, Hackett D, Salinas E. Venlafaxine Extended-Release
(ER) in the Treatment of Generalized Anxiety Disorder. Study
Abstract.
(10) ibid.
(11) Papp LA, Gorman JM. Anxiety Disorders, p. 1238. Comprehensive
Textbook of Psychiatry/VI, vol. 1, sixth edition. Ed. Kaplan H and
Sadock B. 1995.
(12) Diagnostic and Statistical Manual of Mental Disorders Fourth Edition
(DSM-IV), American Psychiatric Association. Generalized Anxiety
Disorders. 2000.
(13) ibid.
(14) ibid.
(15) Bell J. Generalized Anxiety Disorder, p. 88. Psychiatric Secrets. Ed.
Jacobson JL and Jacobson AM. 1995.
(16) National Institute of Mental Health (NIMH), "Facts about Anxiety
Disorders." 1999. National Institutes of Health (NIH) Fact Sheet.
SOURCE: Karolinska Institutet Neurotec <<
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