Such interventions would have the potential to reduce the prevalence of chronic pain in the population .
Although certain risk factors can identify individuals who are most likely to develop chronic pain , few interventions to prevent chronic pain have been identified .
To facilitate the identification of preventive interventions , an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain .
We present general design considerations for prevention trials in population s that are at relatively high risk for developing chronic pain .
Effect of early administration of the N-methyl-d-aspartate receptor antagonist amantadine on the development of postmastectomy pain syndrome: a prospective pilot study.
UNLABELLED Postmastectomy pain syndrome ( PMPS ) is a neuropathic pain syndrome that might develop after breast surgery . Like many other forms of neuropathic pain , it is relatively resistant to treatment and negatively affects the quality of life . A double-blind , r and omized , placebo-controlled pilot trial was conducted to study the analgesic efficacy of perioperative administration of the N-methyl-D-aspatrate ( NMDA ) receptor antagonist amantadine in preventing PMPS after mastectomy plus axillary lymph node dissection ( ALND ) . In the study group , a regimen of 200 mg/day of amantadine was started 1 day before surgery and continued for 14 days , whereas the control group received a placebo .  Patients were required to indicate the exact location of their pain and to record its level at 1 , 3 , and 6 months after surgery . Neurologic examination and Quantitative Thermal Testing ( QTT ) were performed 1 and 6 months after surgery . On both the neurologic examination and the QTT , all patients , regardless of the perioperative intervention ( amantadine or placebo ) , presented evidence for nerve injury , manifested primarily by painful hypoesthesia ( anesthesia dolorosa ) in the axilla or inner arm . PMPS persisted for the entire duration of the study in 82 % of the patients who were available for follow-up . The average intensity of the pain was moderate in both groups and tended not to decline over time . No differences between the 2 groups in any of the outcome parameters reached statistical significance . According to the results of the present pilot study , the NMDA antagonist amantadine does not prevent the development of PMPS in patients who undergo breast surgery with ALND . PERSPECTIVE Breast surgery that involves ALND seems to uniformly cause nerve injury , which can not be prevented by the perioperative administration of 200 mg of amantadine . It is most commonly presented by painful hypoesthesia or anesthesia dolorosa in the axillary/inner arm area , which is moderate in intensity and likely to persist for at least 6 months
Such interventions would have the potential to reduce the prevalence of chronic pain in the population .
Although certain risk factors can identify individuals who are most likely to develop chronic pain , few interventions to prevent chronic pain have been identified .
To facilitate the identification of preventive interventions , an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain .
We present general design considerations for prevention trials in population s that are at relatively high risk for developing chronic pain .