Relationship between pain relief and improvements in patient function/quality of life in patients with painful diabetic peripheral neuropathy or postherpetic neuralgia treated with pregabalin.

Abstract

BACKGROUND:

In patients with chronic pain due to diabetic peripheral neuropathy (DPN) or postherpetic neuralgia (PHN), pregabalin treatment results in pain relief and improved patient function/quality of life (QoL). Few studies, however, have examined the exact relationship between pain relief and improvements in patient function/QoL. It is unclear, for example, whether pregabalin has a direct independent effect on patient function/QoL or whether improvements in function/QoL are an indirect consequent of pain relief.

OBJECTIVES:

To determine whether improvements in function/QoL in response to pregabalin treatment are related to the extent of pain relief in patients with neuropathic pain due to DPN or PHN and to determine whether pregabalin has a direct independent effect on patient function/QoL that is distinct from its effects on pain.

METHODS:

Data from 11 randomized, double-blind, placebo-controlled trials of pregabalin for the treatment of DPN or PHN were pooled for this analysis. Changes in patient function/QoL scores were plotted according to the extent of pain relief to assess whether greater levels of pain relief were associated with greater improvement in function/QoL. A novel mediation analysis was used to asses to what extent the effects of pregabalin on function/QoL scores are a direct treatment effect as opposed to an indirect effect mediated through improvements in pain or sleep.

RESULTS:

Moderate-to-substantial pain relief (a ≥30% decrease in pain) in response to pregabalin treatment was associated with significant (P < 0.05) improvements in 36-Item Short Form Health Survey (SF-36) scores (used to assess patient function/QoL). In many patients, greatest improvement in SF-36 scores was reported by patients achieving ≥50% decrease in pain. Analysis of Patient Global Impression of Change scores revealed a similar trend, where >80% of patients who achieved substantial pain relief also reported their status as much or very much improved. A substantial direct pregabalin treatment effect was evident for many SF-36 domains that could not be explained by pain relief or improvement in sleep.

CONCLUSIONS:

In patients with chronic pain due to DPN or PHN, improvements in patient function/QoL in response to pregabalin treatment are correlated with the extent of pain relief. However, such improvements in function/QoL are not mediated entirely through pain relief but are the result of a combination of pregabalin's effects on pain and sleep disturbance and a direct effect on patient function itself.

• Authors: Aaron Vinik, Birol Emir, Raymond Cheung, Ed Whalen
• Journal: Clinical therapeutics (Clin Ther) Vol. 35 Issue 5 Pg. 612-23 (May 2013) ISSN: 1879-114X [Electronic] United States
• PMID: 23541708 (Publication Type: Journal Article, Meta-Analysis, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Elsevier HS Journals, Inc. All rights reserved.

Chemical References

• Analgesics
• Pregabalin
• gamma-Aminobutyric Acid

Topics

• Analgesics (therapeutic use)
• Diabetic Neuropathies (drug therapy, physiopathology)
• Health Surveys
• Humans
• Neuralgia, Postherpetic (drug therapy, physiopathology)
• Pregabalin
• Quality of Life
• Randomized Controlled Trials as Topic
• Sleep Wake Disorders (drug therapy, etiology)
• Treatment Outcome
• gamma-Aminobutyric Acid (analogs & derivatives, therapeutic use)