Pain management in knee osteoarthritis is a big challenge for patients as well as therapists. Trans-capsaicin, a high purity synthetic capsaicin has demonstrated a significant improvement in osteoarthritis-associated pain as reported by TRIUMPH study 1 published in 'Arthritis and Rheumatology'. Capsaicin was utilized for its long-term analgesic effect to address the pain issues in knee osteoarthritis. The highly purified injectable form of trans-capsaicin in 1 mg dosage provided great relief from knee pain at 12 weeks with a sustained effect till week 24 compared to placebo.

One seventy two patients of age 45-80 years with radiographic evidence of chronic knee osteoarthritis were enrolled in the study from multiple sites in US. Trans-capsaicin was administered in two doses-0.5 mg and 1 mg and confirmed by ultrasound or joint fluid aspiration. Trans-capsaicin 1mg showed a quicker response with improvement in walking on flat surface, reduced stiffness and improvement in function compared to placebo.

Trans-capsaicin injection did not lead to increased occurrence of adverse effects compared to placebo probably because of very short half life (less than 4 hours) of the drug.

'A single intraarticular injection of trans-capsaicin 1.0 mg provides ≥50% reduction in OA knee pain that persists up to 24 weeks', culminated the study authors.