Duloxetine in the treatment of generalized anxiety disorder

Abstract

Duloxetine, a medication with effects on both serotonin and noradrenaline transporter molecules, has recently been approved for the treatment of generalized anxiety disorder. The evidence for its effi cacy lies in a limited number of double blind, placebo controlled comparisons. Statistically signifi cant improvements in the Hamilton Anxiety Rating Scale from baseline were demonstrated in all studies at doses of 60 to 120 mg per day. The signifi cance of such changes in terms of clinical improvements compared to placebo is less certain, particularly when the effect size of the change is calculated. In comparative trials with venlafaxine, duloxetine was as effective in providing relief of anxiety symptoms. In addition to improvements in clinical symptoms duloxetine has also been associated with restitution of role function as measured by disability scales. Duloxetine use is associated with nausea, dizziness, dry mouth, constipation, insomnia, somnolence, hyperhidrosis, decreased libido and vomiting. These treatment emergent side effects were generally of mild to moderate severity and were tolerated over time. Using a tapered withdrawal schedule over two weeks in the clinical trials, duloxetine was associated with only a mild withdrawal syndrome in up to about 30% of patients compared to about 17% in placebo treated patients. Duloxetine in doses of up to 200 mg twice daily did not prolong the QTc interval in healthy volunteers. Like other agents with dual neurotransmitter actions duloxetine reduces the symptoms of generalized anxiety disorder in short term treatments. Further evidence for its effi cacy and safety in long term treatment is required.

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

“…As concerns safety and tolerability, the dropout rate (15% in the ESC group, 13% in the DUL group) was comparable with data reported in literature (Baldwin and Polkinghorn, 2005;Norman and Olver, 2008). Generally, escitalopram seem better tolerated in the early phases of treatment (first month), whereas in the long term both drugs seem more or less equally manageable.…”

“…Previous research has highlighted the advisability of combined treatment (Ferrero et al, 2007) in subjects with GAD and PD. This study seems to confirm those preliminary evidences, emphasizing the value of psychological treatment in subjects with GAD who failed to respond to medication (Katzman, 2009;Norman and Olver, 2008).…”

“…To maintain a naturalistic setting the subjects (N ¼ 43) were assigned to Escitalopram (ESC,N ¼ 20) or Duloxetine (DUL, N ¼ 23) treatment groups according to the therapist's clinical impression based on previous history of treatment and overall clinical features, taking into account previous treatments with drugs (Norman and Olver, 2008) and individual clinical features (Davidson, 2009).…”

“…Comparative studies on the effectiveness of duloxetine and escitalopram in the treatment of subjects with GAD are somewhat scarce. Available data on duloxetine treatment derived by 10-12 week clinical trials have produced incomplete evidences about extended response and durability of effect; moreover, these trials excluded comorbidity, therefore reducing the generalizability of their results to ''real world'' patients (Norman and Olver, 2008). …”

Trajectories of depression symptom improvement and associated predictor analysis: An analysis of duloxetine in double-blind placebo-controlled trials

“…This effect was most strongly demonstrated in item 1 (depressed mood), a core symptom of depression, and item 10 (anxiety: psychic). Improvement in symptoms of anxiety, even in nonremitters, makes sense given DLX's demonstrated efficacy in the treatment of anxiety (Norman and Olver, 2008).…”