Effectiveness of Lidoderm in Reducing Pain in Post-Op Unilateral Knee Replacement

AUSTIN, TX—Arash Nafissi, DO, and colleagues of Hospital for Joint Disease, New York University, report that placing a topical Lidoderm patch provides an effective adjunct treatment in post-operative pain management. Results were presented at the American Pain Society’s 30th Annual Scientific Meeting.

This randomized, double-blind, placebo-controlled trial was designed to assess the effectiveness of Lidoderm (lidocaine 5%) patch in reducing pain and opioid use in post-operative unilateral knee replacement patients. One Lidoderm or placebo patch was cut in half and placed on either side of the incision of the operated knee, for 12 hours on and 12 hours off each day. Both groups received their regular pain medications as needed, which included acetaminophen/codeine, acetaminophen/hydrocodone, acetaminophen 325mg/oxycodone 5mg (Percocet), hydromorphone, tramadol, or celecoxcib. Pain levels were based on a 10-point numerical analog scale and were assessed daily for seven days.

A total of 87 patients were randomized, 44 in the Lidoderm group and 43 in the placebo group. The mean amount of Percocet used was 24.76 (SD=16.45) in the Lidoderm group and 27.76 (SD=22.35) in the placebo group (P=0.64). The mean amount of Percocet used per day was 3.53 (SD=2.34) in the Lidoderm group and 3.90 (SD=3.21) in the placebo group (P=0.71). The mean decrease in pain scale for the Lidoderm group was 3.01 (SD=2.42) and 2.08 (SD=1.70) for the placebo group, and was significant (P=0.003). No side effects reported.

The investigators concluded that patients using Lidoderm patches had an overall lower pain level that was statistically significant over a seven-day post-operative period. Also, the average total and daily Percocet use was lower in the Lidoderm group.