A study, published in Pain Medicine, found that hyperalgesia and the absence of nonpain symptoms, such as tingling or numbness, predicted response to pregabalin among patients with chronic posttraumatic neuropathic pain (PTNP).
This study was a secondary analysis of data from an international, multicenter, placebo-controlled randomized clinical trial of pregabalin (Clinical Trails.gov Identifier: NCT01701362). The trial included patients with PTNP (N=539) who received a 3-week dose optimization of 150, 300, 450, or 600 mg per day pregabalin followed by 12 weeks of treatment or placebo (randomized 1:1). At week 15 the primary efficacy of mean daily pain was evaluated using a 10-point numerical rating scale.
For this secondary analysis, pain outcomes were evaluated on the basis of baseline sensory phenotype due to cause of pain (surgical vs trauma), induced pain (hyperalgesia vs allodynia vs neither), and sensory symptoms (tingling vs numbness/paresthesia vs neither).
Patients were aged mean 53 years, 49% had postsurgical pain, and baseline pain score was 6.45 points. The original trial found that pregabalin did not improve pain scores at week 15 compared with placebo (P =.18).
At baseline, the sensory phenotype assessment found that 55% had hyperalgesia, 52% allodynia, and 92% numbness/paresthesia.
A significant treatment effect for hyperalgesia or allodynia (estimate, -0.5831; P =.0073) and a treatment-by-hyperalgesia interaction (estimate, -0.9495; P =.0067) were observed. The change in pain scores were -0.76 among patients with hyperalgesia compared with 0.19 for those without hyperalgesia.
In addition, the subset of patients without tingling, numbness, or paresthesia sensory symptoms were found to have a significant response to pregabalin (estimate, -1.3596; P =.02998). The change in pain scores were -1.40 among those without nonpainful sensory symptoms compared with -0.24 for those with symptoms.
This study may have been limited by the sensory phenotype assessment which was based on neurologic exam rather than a quantitative sensory test-based approach.
This study found that the subset of patients with PTNP who have hyperalgesia or those without nonpainful sensory symptoms may be better responders to pregabalin. These findings should be confirmed among an independent cohort.
Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.
Gewandter JS, Sohn MB, De Guzman R, et al. Predicting treatment response with sensory phenotyping in post-traumatic neuropathic pain. Pain Med. 2022;pnac045. doi:10.1093/pm/pnac045