Jeffrey Gudin, MD, is board certified in pain management, anesthesiology, addiction medicine and palliative care. He is affiliated with Englewood Hospital and Medical Center and Rutgers New Jersey Medical School’s Department of Anesthesiology, and is an author, researcher and opinion leader in pain management.
Could you share your perspective on the use of topical analgesics as first-line treatments?
Numerous guidelines recommend topical analgesics for various painful conditions. In its guidance on nonopioid treatments for chronic pain, the CDC recommends topical analgesics as first-line alternatives since they are thought to be safer than systemic medications. In their recently issued guidelines for the management of acute pain from non-low back pain, due to musculoskeletal injuries, the American College of Physicians (ACP) and American Academy of Family Physicians (AAFP) recommend the first-line use of topical NSAIDs with or without Menthol. At least four other guidelines, including those issued by the American College of Rheumatology, recommend topical NSAIDs first-line for patients with osteoarthritis. Regarding the risks associated with oral medications, opioids have received the most attention, but oral NSAIDs have serious risks associated with their use as well, including gastrointestinal bleeding and increased risk for cardiovascular events and renal injury. Even acetaminophen, the most commonly used oral over-the counter (OTC) pain reliever, has a narrow therapeutic window, posing the serious risk for hepatotoxicity.
Can you tell us about the Salonpas Pain Relief Patch LARGE?
The Salonpas Pain Relief Patch LARGE is an OTC topical patch containing two active ingredients, menthol 3% and methyl salicylate 10%, which have been associated with significant pain relief with minimal adverse events. These ingredients provide analgesia by acting on nociceptors via multiple mechanisms of action, including acting on transient receptor potential vanilloid subtype 1 (TRPV1) channels. Methyl salicylate is hydrolyzed to the NSAID salicylic acid in the skin and surrounding tissue, providing local anti-inflammatory effects and increasing the threshold for nerve firing. In addition to multiple mechanisms of action, the patch itself is novel, with two-way stretch flexibility that optimizes adhesion throughout the eight- to 12-hour period of application. This analgesic patch starts to work within an hour and provides long-lasting relief for up to 12 hours.
Can you speak to the clinical and regulatory support behind the product?
The Salonpas Pain Relief Patch Large is the first OTC topical analgesic to be FDA approved via the rigorous New Drug Application process, and is the first OTC analgesic approved for mild and moderate pain. The pivotal study that supported this broad indication was conducted by Yoshinobu Higashi et al, which assessed the efficacy and safety of the product in adult patients with mild to moderate pain. This study was a randomized, double-blind, parallel-group, placebo-controlled, multicenter study, involving 208 patients. Importantly, it was this study that showed that the product provided a clinically meaningful analgesic effect starting within the first hour of application and for up to 12 hours. The product was highly effective, providing 40% additional pain relief compared with placebo. Satisfaction with treatment was rated as good, very good or excellent by 58% of patients.
Can you speak to the safety or risks with this product?
In general, the main benefit of topical analgesics is targeting medication delivery to the local site of pain and minimizing systemic exposure/plasma concentrations compared with oral dosing. In the pivotal study mentioned above, the number of patients experiencing any type of adverse event was comparable between the active and placebo study groups, and no serious adverse events were reported during the study. Salonpas was safe and well tolerated.
Dr. Gudin, you’re the lead investigator of the RELIEF Study, a study involving a topical analgesic, the Salonpas Pain Relieving Patch containing Methyl Salicylate 10%, Menthol 6%, and Camphor 3.1%, can you tell us what compelled you to study this analgesic?
The CDC recommends topical agents as alternative first-line treatments, stating they may be safer than systemic medications. Safety is important, but so is efficacy. The RELIEF Study, evaluated both, as well as quality of life and the use of concomitant pain medications. This is especially important to document as the advocacy of topical analgesics is mounting. The RELIEF study assessed patients with arthritic, neurologic, and musculoskeletal pain.
Can you tell me about the RELIEF Study?
The RELIEF Study was a 14 day duration observational study with a 152 patient group treated with the Salonpas Pain Reliving Patch and a 47 patient control group. In addition, after being in the control group for 14 days, a 34 patient cross-over group, was treated with the Salonpas Pain Relieving Patch for 14 days. Patients in each group could also use oral pain medications including: other OTC medications, prescription NSAIDs, opioids and anticonvulsants. This observational design gave us the ability to see how the Salonpas Pain Relieving Patch performed in a real-world setting, accessing measures including: pain severity, pain interference with key quality of life measures, side effects, and the potential reduction of use of oral pain medications.
How did the Salonpas Pain Relieving Patch do?
Recognizing that this was an observational, and not a randomized, controlled, blinded efficacy trial, the results were quite impressive. Patients treated with the Salonpas® Pain Relieving Patch reported an almost 50% reduction in pain severity and a substantially better quality of life, with a 58% reduction in overall pain interference scores with comparable reductions in interference in each key measure including: general activity, mood, ability to walk, normal work, social relationships, sleep, and life enjoyment. Additionally, there were no reported side effects, and 89% of patients in the treatment group reported using less, or a lot less oral pain medications. The pain management community has shown significant interest in the study, it was published in the Journal of Pain Research and abstracts of the study have been accepted for presentation at the recent World Institute of Pain, the International Association for the Study of Pain, and PainWeek.
Very impressive results Dr. Gudin, I am not surprised there is significant interest in the RELIEF Study and topical analgesics in general. Thank you for taking the time to discuss it with us today.