Tuesday, November 28, 2006

Study Shows Pregabalin Effective in Difficult-to-Treat Nerve Pain

November 28, 2006 - 3:38 PM

SYDNEY, Australia, November 28/PRNewswire/ --

- Results Offer Hope to Patients With Excruciating Chronic Pain

Findings from a new study published today in the journal Neurology demonstrate that the oral medication pregabalin is significantly effective in relieving central neuropathic (nerve) pain and improves pain-related sleep disturbance and anxiety in patients with spinal cord injury. Conducted by researchers at the Pain Management Research Institute in Sydney, the study is the largest controlled clinical trial ever of patients with spinal cord injury who suffer from central neuropathic pain, a particularly persistent and severe pain condition.

Results from the study showed that patients using pregabalin (150-600 mg/day) experienced significant improvements in symptoms as early as the first week of treatment and those improvements were sustained throughout the study. Patients taking pregabalin experienced a significant reduction in the average intensity of their pain and significant improvements in pain-related sleep interference as well as a reduction in anxiety compared to those taking placebo.

"Historically it has been extremely difficult to manage patients with central neuropathic pain due to a lack of effective treatments and many people with spinal cord injury have excruciating pain," said Prof. Philip Siddall, lead investigator of the study and Clinical Associate Professor at the Pain Management Research Institute in Sydney. "The study demonstrates that pregabalin is an effective and well-tolerated therapy for treating a range of symptoms that can negatively impact overall quality of life. This study is an important step forward for clinicians trying to improve the lives of patients suffering from difficult-to-treat nerve pains."

Approximately two-thirds of patients with spinal cord injury often suffer from severe central neuropathic pain,[1],[2] which is caused by a lesion or dysfunction in the central nervous system.[3] Patients often describe the symptoms of their pain as burning, tingling, stabbing, shooting, pricking, scalding and freezing.[4],[5],[6] Chronic pain following spinal cord injury may limit a patient's ability to perform daily activities.[7] Consequently, quality of life may be impaired.[8] Central neuropathic pain can occur in patients with spinal cord injury, stroke, multiple sclerosis and neoplasia.

Pregabalin is believed to work by calming hyper-excited neurons or nerve cells which may be an underlying cause for various types of nerve pain.

Based on the results of this study, pregabalin recently became the only therapy to receive European regulatory approval in central neuropathic pain.

About the Study

The study, sponsored by pregabalin (Lyrica(R)) developer Pfizer Inc, was a multicentre, parallel-group, double-blind, randomised clinical trial comparing pregabalin with placebo over a 12-week treatment period in patients with spinal cord injury who had central neuropathic pain as defined by the International Association for the Study of Pain classification. The 12-week treatment period was preceded by a 1-week baseline period during which baseline data were collected. Patients were randomised to receive either flexible dose pregabalin (150-600 mg/day) (n=70) or placebo (n=67) taken twice daily. The primary endpoint of the study was mean pain score as measured by patient pain diary assessments which were completed daily. Patients also rated the extent to which pain interfered with sleep in a daily diary. Changes in anxiety were evaluated using the Hospital Anxiety and Depression Scale (HADS).

Results from the study showed that:

- Patients receiving pregabalin experienced significant improvements in symptoms as early as the first week of treatment and those improvements were sustained throughout the study

- Patients receiving pregabalin experienced a significant reduction in the average intensity of their pain and significant improvements in pain-related sleep interference (p<0.001) as well as a reduction in anxiety (p<0.05) compared to those taking placebo (p<0.001)

- More than 40 percent of patients had greater than a 30 percent reduction in pain as compared to 16 percent of patients on placebo (p=0.001)

- At the end of the study, three times less patients had severe pain in the pregabalin group compared with the placebo group

- Pregabalin was associated with a rapid and significant reduction in pain-related sleep interference (p<0.001) as well as a reduction in anxiety (p<0.05) compared to those patients taking placebo

- The most common adverse events were somnolence and dizziness, which were typically mild to moderate and transient.

About the Pain Management Research Institute

The Pain Management Research Institute (PMRI) is headed by Professor Michael Cousins and brings together around 40 researchers and 40 clinical staff who are involved in pain research and management (http://www.pmri.med.usyd.edu.au/). The Institute also has a strong focus on education and has a number of staff involved in the delivery of a postgraduate degree program in Pain Management through the University of Sydney. This course is delivered on-line and accessible to students internationally. In 2004 the PMRI Educational Program received an international award as an "Exemplary Educational Program". Since 2005, the education program has been available to European and North American students through collaborations with the University of Edinburgh and the University of California, San Francisco.

The pain research program of the PMRI has a broad scope and has a number of teams investigating various aspects of pain epidemiology, neurobiology, psychology and treatment and has gained international recognition for its work in several areas including pain following spinal cord injury. In 1998, the Centre gained one of only eight National Health & Medical Research Council (NHMRC) of Australia awards as a "Centre of Clinical Excellence in Hospital Based Research". In 2005, the PMRI, in collaboration with the University of Queensland (Australia), University College London (UK) and Nagasaki University (Japan) was a recipient of an NHMRC Program Grant (2005-2009). Also in 2005 PMRI was the top level funded institution for a Program Grant from the NSW Health to investigate "Mechanisms and Treatment of Pain Associated with Spinal Cord Injury" (2005 - 2008)

The Pain Management & Research Centre (PMRC) is the clinical arm of the PMRI and conducts clinical treatment programs in acute pain, cancer pain and chronic non cancer pain. PMRC comprises a group of approx 40 multidisciplinary health care practitioners who evaluate all aspects of each patient's pain and recommend treatment options based upon a multidisciplinary approach. PMRC currently provides approx 40,000 episodes of patient care per annum. Each year at least four internationally funded Fellows spend a year of training with PMRC. To date Fellows have been drawn from more than 20 countries.

[1] Bonica JJ. Introduction: Semantic, epidemiologic and educational issues. In: Casey KL, ed. Pain and Central Nervous System Disease. New York: Raven Press, 1991:13-30.

[2] Siddall PJ, Taylor DA, McClelland JM, Rutkowski SB, Cousins MJ. Pain report and the relationship of pain to physician factors in the first 6 months following spinal cord injury. Pain 1999;81(1-2):187-197.

[3] Merskey H, Bogduk N, eds. Classification of chronic pain. Descriptions of chronic pain syndromes and definitions of pain terms. Seattle: IASP Press, 1994:209-212.

[4] Cruz-Almeida Y, Martinez-Arizala A, Widerstrom-Noga EG. Chronicity of pain associated with spinal cord injury: a longitudinal analysis. J Rehabil Res Develop. 2005; 42(5):585-594.

[5] Finnerup N, Johannesen I, Fuglsang-Frederiksen A, Bach FW, Jensen T. Sensory function in spinal cord injury patients with and without pain. Brain. 2003; 126:57-70.

[6] Siddall P, McClelland JM, Rutkowski S, Cousins M. A longitudinal study of the prevalence and characteristics of pain in the first 5 years following spinal cord injury. Pain. 2003; 103:249-257.

[7] Ravensscroft A, Ahmed YS, Burnside IG. Chronic pain after SCI: a patient survey. Spinal Cord. 2000; 38:611-614.

[8] Stensman R. Adjustment to traumatic spinal cord injury: a longitudinal study of self-reported quality of life. Paraplegia. 1994; 32:416-422.

Source: Pain Management Research Institute

For further information, please contact: Resolute Communications, Sejal Sedani, +44(0)20-7357-8187, ext 125, Sejal.sedani@resolutecommunications.com, Lisa O'Sullivan, +44(0)20-7357-8187, ext 134, Lisa.osullivan@resolutecommunications.com

Copyright © 2005 PR Newswire Association LLC. All rights reserved.
A United Business Media Company