Emerging drugs in neuropathic pain

Abstract

Neuropathic pain is a personally devastating and costly condition affecting 3 – 8% of the population. Existing treatments have limited effectiveness and produce relatively frequent adverse effects. Preclinical research has identified many promising pharmacological targets; however, reliable predictors of success in humans remain elusive. At least 50 new molecular entities have reached clinical development including: glutamate antagonists, cytokine inhibitors, vanilloid-receptor agonists, catecholamine modulators, ion-channel blockers, anticonvulsants, opioids, cannabinoids, COX inhibitors, acteylcholine modulators, adenosine receptor agonists and several miscellaneous drugs. Eight drugs are in Phase III trials at present. Strategies that may show promise over existing treatments include topical therapies, analgesic combinations and, in future, gene-related therapies. Recent years have heralded an explosion of pharmaceutical development in neuropathic pain, reflecting advanced knowledge of neurobiology and a heightened perception of the commercial value of neuropathic pain therapeutics. In the interest of improving patient care, the authors recommend implementing comparative studies throughout the development process in order to demonstrate the increased value of novel agents.

Keywords::

• chronic pain
• neuralgia
• neuropathic pain
• neuropathy
• radiculopathy

Acknowledgements

The authors wish to thank R Dworkin and M Field for thoughtful comments made on previous versions of this manuscript. This work was supported by CIHR Grant #69422 and Queen’s University Grant #383-861. I Gilron has received research support from Pfizer, Aventis Pharma, Novopharm, PharmaScience and Apotex and he has received honoraria for consultations and speaker fees for educational presentations from Pfizer, Merck-Frosst, Johnson and Johnson, OrthoMcNeill and Janssen-Ortho. T Coderre has received a research contract from Pfizer and is on the Scientific Advisory Board of PainCeptor Pharma.

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