Objective. To provide recommendations for the core outcome domains that should be considered by investigators conducting clinical trials of the efficacy and effectiveness of treatments for chronic pain. Development of a core set of outcome domains would facilitate comparison and pooling of d

http://www.immpact.org/static/publications/Turk%20et%20al.,%202003.pdf

Core outcome domains for chronic pain clinical trials: IMMPACT recommendations.

Interpreting the Clinical Importance of Treatment Outcomes in Chronic Pain Clinical Trials: IMMPACT Recommendations

http://www.immpact.org/static/publications/Dworkin%20et%20al.,%202005.pdf

Topical Review and RecommendationsCore outcome measures for chronic pain clinical trials: IMMPACT recommendations

Patients with neuropathic pain (NP) are challenging to manage and evidence-based clinical recommendations for pharmacologic management are needed. Systematic literature reviews, randomized clinical trials, and existing guidelines were evaluated at a consensus meeting. Medications were considered for recommendation if their efficacy was supported by at least one methodologically-sound, randomized clinical trial (RCT) demonstrating superiority to placebo or a relevant comparison treatment. Recommendations were based on the amount and consistency of evidence, degree of efficacy, safety, and clinical experience of the authors. Available RCTs typically evaluated chronic NP of moderate to severe intensity. Recommended first-line treatments include certain antidepressants (i.e., tricyclic antidepressants and dual reuptake inhibitors of both serotonin and norepinephrine), calcium channel alpha2-delta ligands (i.e., gabapentin and pregabalin), and topical lidocaine. Opioid analgesics and tramadol are recommended as generally second-line treatments that can be considered for first-line use in select clinical circumstances. Other medications that would generally be used as third-line treatments but that could also be used as second-line treatments in some circumstances include certain antiepileptic and antidepressant medications, mexiletine, N-methyl-D-aspartate receptor antagonists, and topical capsaicin. Medication selection should be individualized, considering side effects, potential beneficial or deleterious effects on comorbidities, and whether prompt onset of pain relief is necessary. To date, no medications have demonstrated efficacy in lumbosacral radiculopathy, which is probably the most common type of NP. Long-term studies, head-to-head comparisons between medications, studies involving combinations of medications, and RCTs examining treatment of central NP are lacking and should be a priority for future research.

/pdf/pharmacologic-management-of-neuropathic-pain-evidence-based-54vtpxvnfe.pdf

Pharmacologic management of neuropathic pain: evidence-based recommendations.

Background and objectives:  This second European Federation of Neurological Societies Task Force aimed at updating the existing evidence about the pharmacological treatment of neuropathic pain since 2005.

Methods:  Studies were identified using the Cochrane Database and Medline. Trials were classified according to the aetiological condition. All class I and II randomized controlled trials (RCTs) were assessed; lower class studies were considered only in conditions that had no top-level studies. Treatments administered using repeated or single administrations were considered, provided they are feasible in an outpatient setting.

Results:  Most large RCTs included patients with diabetic polyneuropathies and post-herpetic neuralgia, while an increasing number of smaller studies explored other conditions. Drugs generally have similar efficacy in various conditions, except in trigeminal neuralgia, chronic radiculopathy and HIV neuropathy, with level A evidence in support of tricyclic antidepressants (TCA), pregabalin, gabapentin, tramadol and opioids (in various conditions), duloxetine, venlafaxine, topical lidocaine and capsaicin patches (in restricted conditions). Combination therapy appears useful for TCA-gabapentin and gabapentin-opioids (level A).

Conclusions:  There are still too few large-scale comparative studies. For future trials, we recommend to assess comorbidities, quality of life, symptoms and signs with standardized tools and attempt to better define responder profiles to specific drug treatments.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1468-1331.2010.02999.x

EFNS guidelines on the pharmacological treatment of neuropathic pain: 2010 revision

Context.—Postherpetic neuralgia (PHN) is a syndrome
of often intractable neuropathic pain following herpes zoster
(shingles) that eludes effective treatment in many patients.Objective.—To determine the efficacy and safety of the
anticonvulsant drug gabapentin in reducing PHN pain.Design.—Multicenter, randomized, double-blind,
placebo-controlled, parallel design, 8-week trial conducted from August
1996 through July 1997.Setting.—Sixteen US outpatient clinical centers.Participants.—A total of 229 subjects were randomized.Intervention.—A 4-week titration period to a maximum dosage
of 3600 mg/d of gabapentin or matching placebo. Treatment was
maintained for another 4 weeks at the maximum tolerated dose.
Concomitant tricyclic antidepressants and/or narcotics were continued
if therapy was stabilized prior to study entry and remained constant
throughout the study.Main Outcome Measures.—The primary efficacy measure was
change in the average daily pain score based on an 11-point Likert
scale (0, no pain; 10, worst possible pain) from baseline week to the
final week of therapy. Secondary measures included average daily sleep
scores, Short-Form McGill Pain Questionnaire (SF-MPQ), Subject Global
Impression of Change and investigator-rated Clinical Global Impression
of Change, Short Form-36 (SF-36) Quality of Life Questionnaire, and
Profile of Mood States (POMS). Safety measures included the frequency
and severity of adverse events.Results.—One hundred thirteen patients received
gabapentin, and 89 (78.8%) completed the study; 116 received placebo,
and 95 (81.9%) completed the study. By intent-to-treat analysis,
subjects receiving gabapentin had a statistically significant reduction
in average daily pain score from 6.3 to 4.2 points compared with a
change from 6.5 to 6.0 points in subjects randomized to receive placebo
(P<.001). Secondary measures of pain as well as changes in
pain and sleep interference showed improvement with gabapentin
(P<.001). Many measures within the SF-36 and POMS also
significantly favored gabapentin (P≤.01). Somnolence,
dizziness, ataxia, peripheral edema, and infection were all more
frequent in the gabapentin group, but withdrawals were comparable in
the 2 groups (15 [13.3%] in the gabapentin group vs 11 [9.5%] in
the placebo group).Conclusions.—Gabapentin is effective in the
treatment of pain and sleep interference associated with PHN. Mood and
quality of life also improve with gabapentin
therapy.

http://www.sunpharma.com.mx/pdfs/gabantin/Rowbotham.pdf

Leslie Magnus-miller

Papers

Gabapentin for the treatment of postherpetic neuralgia: a randomized controlled trial.

Gabapentin for the Treatment of Postherpetic Neuralgia: a Randomized Controlled Study