The addition of Pfizer's Lyrica (pregabalin) capsules CV to other generalised anxiety disorder (GAD) treatments significantly improved the symptoms of the condition in patients who responded only partially to previous treatments, according to a study presented at the American Psychiatric Association annual meeting in San Francisco, California. In this study, patients treated with Lyrica showed significant improvements in both their psychological and physical symptoms of anxiety.

Generalized anxiety disorder is a chronic, debilitating anxiety disorder affecting nearly seven million Americans and is characterized by persistent, excessive, uncontrollable worry about everyday things. Patients also frequently experience physical symptoms such as muscle tension, fatigue, sleep disturbance, and other aches and pains.

The condition is complex and often difficult to treat, with 40 per cent to 60 per cent of patients failing to achieve remission after six months of treatment in clinical studies with serontonin reuptake inhibitors (SSRIs) or serotonin norepinephrine reuptake inhibitors (SNRIs) - two common classes of FDA-approved GAD treatments.

"These data are very encouraging for the high percentage of GAD patients who still struggle with debilitating symptoms despite treatment," said Dr Rakesh Jain, one of the study's investigators and director, adult and child psycho-pharmacology research, R/D Clinical Research, Inc. "It is clear we need additional effective, well-tolerated options to address this difficult to treat condition."

This is the first large, placebo-controlled trial to demonstrate the efficacy of an add-on therapy strategy in patients who had failed to respond to two different courses of GAD monotherapy with a SSRI, SNRI or benzodiazepine.

The study found that patients treated with Lyrica in addition to their baseline SSRI/SNRI therapy had a significantly greater improvement in overall anxiety symptoms as well as individual psychological and physical symptoms compared to baseline therapy alone as measured by the Hamilton Anxiety Scale (HAM-A), an interview scale that measures the severity of a patient's anxiety. Over the eight week treatment period, patients receiving add-on Lyrica therapy had, on average, an anxiety score that was 1.2 points lower on the HAM-A compared to baseline therapy alone (P=0.012).

Significantly more patients receiving add-on Lyrica treatment (50 per cent) showed at least a 50 per cent reduction in their anxiety symptoms compared to SSRI/SNRI treatment alone (37 per cent) (P=0.023). Lyrica was also shown to be well tolerated as an add-on therapy in this study.

In the United States, Lyrica is approved for the management of fibromyalgia, painful diabetic peripheral neuropathy, postherpetic neuralgia (pain after shingles), and for the adjunctive treatment of partial onset seizures (a type of epilepsy) in adults. Lyrica is not approved for GAD in the US.