Efficacy In Neuropathic Pain Research Articles

Ion Channel Targets and Treatment Efficacy in Neuropathic Pain

Chronic neuropathic pain due to injury or dysfunction of the nervous system remains a formidable treatment challenge in spite of a growing range of medication choices. We review current clinical research supporting the use of ion channel modulators for neuropathic pain states. New modes of local drug delivery, novel Ca 2+ channel targets, and increased choices for drugs with activity at Na +channels are transforming this longstanding therapeutic strategy. Clinical decision making is increasingly informed by a more nuanced understanding of the role of voltage-gated Na +channels (VGSCs) and Ca 2+ channels (VGCCs) in the pathophysiology of nerve injury. Although holding great promise for the future, mechanism-based approaches to treatment will require greater understanding of the analgesic mechanisms of drug action and of the relationships between pathophysiologic mechanisms and clinical presentation. Perspective Treatment options for neuropathic pain targeting ion channels have grown rapidly in the past decade. An evolving body of clinical research supports the widespread use of this longstanding therapeutic strategy. Improved efficacy of ion channel modulators hinges upon further elucidation of the relationship between signs and symptoms of pain and underlying pathophysiology.

Recent advances in the diagnosis and management of diabetic neuropathy

The World Health Organisation estimated that in the year 2000, 150 million people had diabetes mellitus, and it is predicted that this number will rise to 366 million by the year 2030.[1][1] Neuropathy is a common complication of diabetes and is characterised by a progressive loss of peripheral

A Randomized, Placebo-Controlled Trial of Bupropion Sustained Release in Chronic Low Back Pain

Clinical trials of the efficacy of antidepressant drugs in patients with chronic low back pain have had mixed results, possibly because of the different mechanisms of action of the drugs that have been studied. Because bupropion has a mechanism of action that differs from other antidepressants and has shown efficacy in neuropathic pain, a randomized, placebo-controlled, 2-period crossover trial was conducted to evaluate its efficacy in subjects with chronic low back pain. The primary efficacy variable was mean daily diary pain intensity ratings, and secondary pain intensity and relief outcomes included weekly pain intensity ratings, the McGill Pain Questionnaire (MPQ) Present Pain Intensity scale, pain relief ratings, and satisfaction with pain relief ratings. Adverse events were also assessed throughout the trial. Analyses were performed of an intention-to-treat sample of 44 patients, only 3 of whom met criteria for neuropathic low back pain. Daily and weekly pain intensity ratings, the MPQ Present Pain Intensity scale, and pain relief ratings were not significantly different following treatment with bupropion sustained release (SR) vs. placebo. These results suggest that bupropion SR was not significantly better than placebo in the treatment of patients with non-neuropathic chronic low back pain. Perspective Antidepressant medications that have both noradrenergic and serotonergic effects appear to have greater efficacy in patients with chronic low back pain than those with only serotonergic activity. We studied bupropion because it inhibits the reuptake of both norepinephrine and dopamine, but found no evidence of efficacy in patients with non-neuropathic chronic low back pain.

Opioids in Neuropathic Pain

Opiates lack potent analgesic efficacy in neuropathic pain although it is now generally accepted that the poor effect of these drugs reflects a reduction in their potency. Reduction of morphine antinociceptive potency was postulated to be due to the fact that nerve injury altered the activity of opioid systems or opioid specific signaling. Endogenous opioid systems were found to be represented in the regions involved in the nociception and are implicated in chronic pain. Opioid peptides biosynthesis and opioid receptors density in the nociceptive pathways and their functions change under various conditions associated with neuropathic pain following damage to the spinal cord and injury of peripheral nerves. Identification of a role of opioid systems in neuropathic pain and molecular and cellular mechanisms underlying these processes are of importance to understanding of the opioid action in neuropathic pain that will hopefully facilitate development of therapeutic strategies in which effectiveness of opioids in alleviation neuropathic pain is increased.

Topical doxepin hydrochloride reduces neuropathic pain: a randomized, double-blind, placebo controlled study

Tricyclic antidepressants have a proven efficacy in neuropathic pain but their use is frequently complicated by side-effects. In a randomized, double-blind, placebo controlled study we compared the effect of twice daily application of doxepin hydrochloride 5% and placebo in forty patients with neuropathic pain. Results were obtained from 75% of those enrolled. There was a significant reduction in pain scores (linear visual analogue scores, 0-10) in those treated with topical doxepin hydrochloride when compared to placebo (mean fall in doxepin group 1.18, P < 0.01). minor side-effects were seen in 3 patients. there was no significant difference drowsiness levels in the two groups.We conclude that topical doxepin hydrochloride has an analgesic effect in neuropathic pain and its use is not commonly complicated by side-effects.