Patch therapy provides similar pain relief as oral medications for patients with osteoarthritis (OA) knee pain

Researchers from the Altoona Arthritis and Osteoporosis Center have announced that data presented at the 24th Annual Scientific Meeting of the American Pain Society suggest that patch therapy provides similar pain relief as oral medications for patients with osteoarthritis (OA) knee pain. The research involved a head to head comparison of applying the lidocaine patch 5% (Lidoderm) or taking celecoxib (Celebrex) 200 mg per day.

Results showed that at six weeks 54 % of patients treated in the lidocaine patch 5% (Lidoderm) group (N=56) and 62 % of patients in the celecoxib (Celebrex) group (N=63) experienced a 30 % or greater improvement in pain intensity. A 30 % or greater reduction in pain intensity is considered clinically meaningful to pain patients.

"These findings are encouraging for OA knee pain patients wanting alternatives to current oral medications," said Dr. Alan J. Kivitz, founder and lead physician, Altoona Arthritis and Osteoporosis Center, and study author. "With medication safety being on the minds of many people, it's promising for patients and their physicians that there are non-systemic therapies being studied for OA pain which may provide future options."

OA affects more than 20 million Americans annually and generates more than seven million physician visits per year. If left untreated, chronic pain conditions such as OA can have significant physical, psychological and financial consequences by impacting daily functioning and quality of life.

Analyzing results from 143 patients experiencing OA pain of either one or both knees, the randomized, open-label, active-control, parallel-group study found that clinically meaningful reductions in pain were noted in the lidocaine patch 5% and the celecoxib groups at week 12. In this study, 71 percent of patients in the lidocaine patch 5% group (N=24) and 72 percent of patients in the celecoxib group (N=39) experienced a 30 percent or greater improvement in average daily pain intensity.

In the study, both treatments were well tolerated, with adverse events reported in eight patients in each group. The most common adverse events were itchiness or redness at the patch site. Additionally, three patients in the Lidoderm group discontinued the study due to adverse events (typically other pain, not being treated). There were no discontinuations due to treatment-related adverse events in the Celebrex group.

However, due to recent safety concerns regarding the entire COX-2 inhibitor class, the sponsor of the study, Endo Pharmaceuticals Inc., voluntarily elected to prematurely halt the study prior to reaching the original enrollment target of 200 patients. These results therefore need to be confirmed with further randomized controlled trials.

"This is the first clinical study that compares a prescription topical patch with a COX-2 inhibitor," said Dr. Kivitz. "The results are encouraging and establish the foundation for further studies into non-systemic options for the treatment of OA pain."

Lidoderm is topical analgesic patch, approved by the U.S. Food and Drug Administration (FDA) in 1999 to treat the pain associated with post-herpetic neuralgia (PHN), a chronic condition resulting from nerve damage caused by shingles. As it is a non-systemic treatment, Lidoderm has demonstrated a minimal risk of side effects and drug-to-drug interactions. Celebrex is a COX-2 inhibitor indicated for the treatment of arthritis pain including OA.