Topical treatment of chronic low back pain with a capsicum plaster.

The efficacy and tolerance of a capsicum plaster in non-specific low back pain was investigated in a double-blind, randomised, placebo-controlled multicentre parallel group study. A total of 320 patients were randomly assigned to two groups of n=160 subjects treated by the active or the placebo plaster. The main outcome measures used were a compound pain subscore of the Arhus low back rating scale (continuous variable), and a response criterion of a reduction in pain subscore=30% from baseline to final assessment (secondary, non-continuous variable). In addition, the partial pain scores, disability and mobility restriction subscores, the total score of the Arhus low back rating scale, the global evaluation of efficacy by investigator and patient, adverse events, a patient questionnaire on use of the plaster, and an evaluation of tolerance by investigator and patient were obtained. After 3 weeks treatment with capsicum and placebo plaster respectively, the compound pain subscore was reduced by 42% (capsicum) and 31% (placebo) from values on entry. Responder rate was 67% versus 49% (p=0.002). The investigators rated efficacy as "excellent" or "good" by 74% and 36%; the patient's efficacy rating "symptomfree" or "improved" reached 82% and 50%. Adverse local drug reactions were found in 12 patients (7.5%) on capsicum and 5 (3.1%) on placebo. No systemic side-effects were observed. The superiority of the treatment of chronic non-specific low back pain with capsicum plaster compared to placebo was clinically relevant and highly statistically significant. The capsicum plaster offers a genuine alternative in the treatment of non-specific low back pain.