A Meta-Analysis of the Efficacy of Pregabalin in the Treatment of Generalized Anxiety Disorder

Abstract

Objective: Generalized anxiety disorder (GAD) is a chronic anxiety disorder that leads to significant functional impairment and reduced quality of life. Pregabalin is a novel analogue of the inhibitory neurotransmitter gamma amino butyric acid, which has been proposed as a treatment for a range of conditions including GAD. This study examined the efficacy of pregabalin for GAD across published trials, using a meta-analytic method.Method: This study examined the 7 published placebo-controlled trials of GAD using pregabalin, and, using meta-analytic techniques, we calculated the effect size of treatment with pregabalin (compared with placebo) on a total of 1352 people. Results:The overall effect size of pregabalin in the treatment of GAD was Hedges' g = 0.364, with an effect size of 0.349 on psychic anxiety symptoms and of 0.239 on somatic anxiety symptoms. Conclusion:Pregabalin is an efficacious therapy for GAD, although effect sizes are smaller than those from earlier studies. Limitations and future research directions are discussed.Can J Psychiatry. 2011;56(9):558-566. Clinical Implications• Pregabalin is an effective treatment for GAD in adults, supported by a body of 7 randomized controlled trials (RCTs).• Pregabalin exerts a greater effect against psychic anxiety symptoms, compared with somatic anxiety symptoms. Limitations• The current meta-analysis is based only on participants taking the largest doses of pregabalin during the RCTs.• The current meta-analysis incorporated a range of dosing regimes into a single analysis.• The published RCTs of pregabalin in GAD all received financial support from Pfizer and have all been conducted by a small number of independent research teams.

Alpha2delta ligands, gabapentin, pregabalin and mirogabalin: a review of their clinical pharmacology and therapeutic use

“…A meta-analysis of 7 placebo-controlled trials of pregabalin for the treatment of generalized anxiety disorder found the overall effect of pregabalin to be significant but small, with a Hedges' g of 0.364, and similarly small for psychic anxiety symptoms (0.349) and somatic anxiety symptoms (0.239) [107]. Using a Bayesian meta-analytic approach, Baldwin et al evaluated the comparative efficacy and tolerability of several drugs for the treatment of GAD, including SSRIs, SNRIs, lorazepam, pregabalin and tiagabine [108].…”

Effectiveness of Pregabalin as Monotherapy or Combination Therapy for Neuropathic Pain in Patients Unresponsive to Previous Treatments in a Spanish Primary Care Setting

“…Pregabalin use is becoming widespread in psychiatry and addiction-related treatments. Evidence derived from different studies suggests that pregabalin is an efficacious therapy for GAD [35] and social anxiety disorder [36], with some preliminary evidence for its efficacy in relapse prevention. It is also used as adjunctive therapy in many other psychiatric conditions, such as obsessive compulsive disorder [37], post-traumatic stress disorder, schizophrenia, bipolar mania [38], and major depression [39].…”

Pregabalin augmentation of antidepressants in older patients with comorbid depression and generalized anxiety disorder—an open‐label study

“…Although pregabalin has demonstrated a significant advantage over placebo in treating GAD in adults, the effect sizes demonstrated to date are small to moderate and psychic symptoms show a greater improvement compared with somatic anxiety symptoms. In contrast, our study found that somatic symptoms seem to improve more (Boschen, 2011). In addition, most studies only evaluate the initial phase of treatment (6-8 weeks), whereas GAD is generally regarded as a long-term condition requiring long-term treatment.…”