© 2008 The Royal College of Psychiatrists
Efficacy and safety of pregabalin in elderly people with generalised anxiety disorder*
Imperial College School of Medicine, University of London, UK
Pfizer Global Research and Development, Sandwich, UK
Pfizer Global Research and Development, Ann Arbor Michigan, USA
Pfizer Inc, New York, New York, USA
Correspondence: Professor Stuart A. Montgomery, PO Box 8751, London W13 8WH, UK. Email: stuart{at}samontgomery.co.uk
This study was sponsored by Pfizer Inc. S.M. has served on advisory boards for Pfizer, has received fees as a consultant to Pfizer, and has been reimbursed for travel-related expenses incurred for scientific meetings. K.C., L.P., E.W. and F.B. are full-time employees of Pfizer.
* Presented in part at the 159th Annual Meeting of the American Psychiatric Association, Toronto, Canada, 20–25 May 2006.
Background
Pregabalin is a novel compound that has been shown to have efficacy in the treatment of generalised anxiety disorder and is licensed for the treatment of the disorder in the European Union.
Aims
The current study was designed to evaluate the safety and efficacy of
pregabalin, an 
2
-ligand, in the treatment of
generalised anxiety disorder in people 65 years and older.
Method
This was a double-blind, randomised (2:1), placebo-controlled, 8-week trial
of pregabalin, in flexible doses of 150–600 mg/day, in the treatment of
DSM–IV generalised anxiety disorder with a baseline Hamilton Rating
Scale for Anxiety (HRSA) total score 
20. The primary outcome was
end-point (week 8 or last visit, with last observation carried forward (LOCF))
change in HRSA total score.
Results
A total of 273 patients (women, 78%; mean age, 72 years (s.d.=6); mean baseline HRSA total score, 26 (s.d.=4.6)) were randomised and received study treatment. On the primary intent-to-treat LOCF analysis, pregabalin was associated with a 2-point greater reduction in HRSA total score than placebo (12.87 v. 10.7; P<0.05). In a post hoc repeated measures mixed-effect model analysis, pregabalin was associated with significantly greater improvement than placebo in the HRSA total score from week 2 (–9.8 (s.d.=0.6) v. –7.2 (s.d.=0.8); P=0.0052) through week 8 (–14.4 (s.d.=0.6) v. –11.6 (s.d.=0.8); P=0.0070). Significant improvement was observed in the pregabalin group on both the HRSA psychic and somatic anxiety factors. There was a significantly greater decrease from baseline in mean Hamilton Rating Scale for Depression (HRSD) score with pregabalin compared with placebo (–5.48 (s.d.=0.46) v. –4.02 (s.d.=0.59); P=0.041). Pregabalin was well-tolerated, with almost all adverse events in the mild-to-moderate range, and self-limiting (median duration of 4–16 days). Discontinuations due to adverse events were similar for pregabalin (10.7%) and placebo (9.4%).
Conclusions
Pregabalin, in doses of 150–600 mg/day, was a safe and effective treatment of generalised anxiety disorder in patients 65 years and older. The anxiolytic efficacy of pregabalin had an early onset (by 2 weeks) and significantly improved both psychic and somatic symptoms of anxiety.