D-cycloserine in the Management of Chronic Low Back Pain
Pre-clinical studies in rats suggest that D-cycloserine (DCS) is effective in the management of chronic neuropathic pain. This pilot study will attempt to determine the effect of D-cycloserine in the treatment of neuropathic chronic low back pain. Other aims of this study are to determine the safety of D-cycloserine in the treatment of neuropathic chronic low back pain and to determine which pain measurement scales are best at measuring the efficacy of treatment.
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||D-Cycloserine in the Management of Chronic Low Back Pain: A Double-Blind, Randomized, Placebo-Controlled Pilot Study|
- Change in Numeric Rating Scale (NRS-11) [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]Change in NRS score after 6 weeks of treatment as compared to baseline. The numeric rating scale is an 11-point rating scale wherein participants rated their current lower back pain intensity on a scale from 0 to 10, with 0 meaning no pain and 10 being the worst pain possible. Thus, a larger negative number indicates positive change and a higher efficacy.
- McGill Pain Questionnaire (MPQ) [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]Change in MPQ score after 6 weeks of treatment as compared to baseline. The MPQ score uses a Pain Rating Index from 0 to 20 where 0 is evidence of no pain and 20 indicates the highest pain possible. A lower score is also indicative of a lower quality of pain. Thus, a larger negative number indicates positive change and therefore higher efficacy.
|Study Start Date:||July 2012|
|Study Completion Date:||November 2014|
|Primary Completion Date:||April 2014 (Final data collection date for primary outcome measure)|
D-cycloserine 50mg bid/100mg bid/200 mg bid
D-cycloserine 50 mg bid; D-cycloserine 100 mg bid; D-cycloserine 200 mg bid
Placebo Comparator: 2
Human brain imaging studies indicate that the medial prefrontal cortex activity can predict more than 80% of the variance of chronic back pain intensity. Therefore, the investigators have hypothesized that modulation of brain activity at this site should result in analgesia. D-cycloserine has been shown to potentiate conditioned fear extinction. Based on this the investigators hypothesize that chronic neuropathic pain (back pain with radiculopathy) is partially mediated or potentiated by decreased ability to extinguish the pain memory, which the investigators hypothesize to be mediated through reward/aversion brain circuitry, and specifically through medial prefrontal cortex. They have tested this idea in pre-clinical studies and demonstrated that rats with neuropathic pain show analgesia over the long-term when treated with D-cycloserine. In humans with chronic back pain, the investigators hypothesize that D-cycloserine will enhance extinction of back pain which in turn should result in reduced emotional relevance of the pain, that is reduced suffering. It is quite possible that the overall intensity of the back pain will be unaffected, however, the associated suffering will be significantly attenuated.
This will be a double-blind, randomized, parallel group escalating dose study comparing D-cycloserine twice a day (bid) with placebo bid in patients with neuropathic chronic low back pain. Subjects meeting inclusion criteria will continue baseline medications and be treated for 12 weeks with study drug: 50 mg bid DCS or matching placebo for the first 4 weeks, then 100mg bid DCS or matching placebo for 4 weeks and finally 200mg bid DCS or matching placebo for 4 weeks. Assessments of efficacy and safety will be undertaken every 2 weeks using standard, validated instruments to evaluate change in pain, function, quality of life and adverse events.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00125528
|United States, Illinois|
|Northwestern University Feinberg School of Medicine|
|Chicago, Illinois, United States, 60611|
|Principal Investigator:||Thomas J Schnitzer, M.D., Ph.D.||Northwestern University|
|Principal Investigator:||Vania Apkarian, Ph.D.||Northwestern University|