title: Expert opinion on emerging drugs: chronic low back pain.
abstract: BACKGROUND
  It is difficult to overestimate the personal and socioeconomic impact of chronic low back pain (CLBP). It is the leading cause of years lost to disability and poses the highest economic toll among chronic illnesses. Despite the strong need for extensive research efforts, few drugs have consistently demonstrated effectiveness for this condition.
  
  
  METHODS
  In this review, the epidemiology, rationale for mechanism-based treatment, competitive environment and market trends, and the preclinical and clinical evidence supporting over 15 different classes of analgesic medications studied for CLBP or related pain conditions are discussed. Treatments are divided by drug category, type of CLBP they are likely to treat (e.g., neuropathic or mechanical), and whether they are new formulations of existing treatments, new indications for existing treatments or represent novel mechanisms of action. Databases searched included MEDLINE, Embase, Pharmaprojects and various clinical trial registries.
  
  
  CONCLUSIONS
  Many barriers exist for the development of medications for CLBP including difficulties in identifying pathophysiological mechanisms, biologic resiliency secondary to multiple concurrent pain pathways and off-target and sometimes serious side effects. Nevertheless, the volume and diversity of novel molecular entities has continued to surge and includes possible disease-modifying therapies such as gene and stem cell therapy.
authors.affiliation: Oregon Health and Science University School of Medicine , Portland, OR , USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Hsu
authors.forename: Sunberri
authors.initials: S
authors.lastname: Murphy
authors.forename: David
authors.initials: D
authors.lastname: Chang
authors.forename: Steven P
authors.initials: SP
authors.lastname: Cohen
mesh_terms: D000700:Analgesics / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D059350:Chronic Pain / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology; D015195:Drug Design; D006801:Humans; D017116:Low Back Pain / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology
chemical_list: D000700:Analgesics
keywords: low back pain; mechanical back pain; mechanism-based treatment; pharmacotherapy; radiculopathy; sciatica