Although topical capsaicin therapy has been shown clinically to relieve arthritis pain, the recommended four times a day (QID) application schedule is difficult for some patients to maintain. Therefore, this study was conducted to determine if the analgesic effect achieved on a QID regimen could be maintained with a twice-daily (BID) regimen. Fifty-nine adults with primary osteoarthritis (OA) of the hand were enrolled in this 9-week, double-blind, randomized, parallel-group, vehicle-controlled study consisting of two phases: phase I, QID; and phase II, BID. Patients were treated with either 0.025% capsaicin cream or vehicle cream in the standard regimen (ie, QID) for 3 weeks, and then switched to a “maintenance” regimen of BID for the duration of the study. Capsaicin administered QID was significantly better than vehicle in relieving articular tenderness at weeks 1 and 3 (P = .046 and .018 respectively). When the BID maintenance regimen was begun. capsaicin-treated patients experienced a transient increase in articular tenderness and a decrease in pain relief (visual analog scale). Pain control was reestablished by week 9 as evidenced by a significant reduction (P = .013) in articular tenderness and pain relief (visual analog scale). Local stinging and burning, which were self-limited, were the most common adverse effects. No systemic side effects were noted. Given these findings, it may be prudent to taper the regimen gradually to avoid the decrease in pain relief seen with an abrupt decrease in dosage. This maintenance regimen will likely enhance long-term patient compliance and also result in cost savings to the patient.
- Capsaicin: osteoarthritis
- substance P
ASJC Scopus subject areas
- Anesthesiology and Pain Medicine