Joco Today

A Review Of Topical Products For Pain Relief

Pain is a common disabling condition. There is a need for adjunctive, non-addictive, cost-effective interventions, and various topical pain relievers may be effective in filling this role. Topical analgesic drugs are commonly used for a variety of painful conditions.

Some conditions are acute, often strains or sprains, painful tendon conditions, or other aches and pains. Other conditions are longer lasting or chronic, sometimes related to osteoarthritis involving the spine, hip, knees, shoulders, elbows, or wrists. Topical analgesics may have advantages over other pain medications. They are typically non-opiates, which alleviates concerns related to opioid overuse and addiction.

Topical analgesics can be used at home as self-care, and typically do not have the systemic harms associated with the use of oral anti-inflammatory drugs, including gastrointestinal bleeding or negative cardiovascular effects. Dr. Mark Pfefer, a chiropractor, and the director of research at Cleveland University-Kansas City (CUKC), said topical analgesics are readily accessible to consumers.

“Many topical analgesics are available over-the-counter, and many are relatively affordable for a large number of patients,” Pfefer said. “They are commonly recommended by medical doctors, chiropractors, physical therapists, and other manual therapy providers to reduce pain and disability, to allow for improved sleep, and to encourage less pain with movement, activities, and rehabilitative exercises.”

Pfefer, along with Dr. Stuart McIntosh, a chiropractor and an associate professor at CUKC, led a group of faculty colleagues as they performed an umbrella review of the use of topical capsaicin and menthol products for pain in adults. Capsaicin is a chemical component found in chili peppers, and menthol is an organic compound found in the oils of several types of mint. An “umbrella” review is a high-level evidence synthesis that only considers other systematic reviews and meta-analyses in published research, which allows relevant research findings to be compared and contrasted. An umbrella review provides a quick, concise overview of a particular clinical issue.

The aim of this review project was to describe proposed mechanisms and evaluate the effectiveness of topical menthol-based and capsaicin-based over-the-counter pain relievers.  The research team performed a search of medical literature using MEDLINE, CINAHL, Cochrane Central Register, and Index to Chiropractic Literature. All eligible articles were reviewed then scored using the methodology for Joanna Briggs Institute (JBI) Umbrella Reviews. Two independent reviewers performed the scoring of articles. This review paper has been accepted for presentation at the 2023 Association of Chiropractic Colleges Research Agenda Conference.

Numerous publications regarding the mechanisms and effectiveness of topical agents for pain were located. Ultimately, eleven review articles regarding menthol-based agents, and twenty-three review articles regarding capsaicin-based agents were included in this review.

The discovery of novel topical analgesics is becoming an active area of research owing to problems with existing pain-relieving drugs, including addiction, gastrointestinal bleeding, heightened cardiovascular risk, and liver toxicity. Modulators of temperature-sensing transient receptor potential ion channels, in particular TRPV1, TRPV2, TRPM8, and TRPPA1, have reached clinical development. There are potentially a number of modulators of these channels that can be studied related to pain relief including menthol and capsaicin.

Transient receptor potential melastin-8 (TRPM8), a cationic ion channel, generates a normal cooling sensation in mammals. TRPM8 activation by cooling or chemical agonists has been shown to produce profound analgesia in chronic pain states such as neuropathic pain in animals. This provides a molecular basis for understanding the potential action of menthol and other compounds and their ability to produce both a cooling sensation and reduction of pain associated with a variety of painful stimuli and conditions. Capsaicin also activates the transient potential vanilloid 1 receptor of C-type pain sensors in mammals.

The research team found that there is good evidence that topical menthol and capsaicin-based analgesics may represent an effective and safe alternative to oral pain medications. Both menthol and capsaicin have a good safety profile and efficacy, especially in reducing osteoarthritis pain of the hand, knee, hip, or shoulder.

Although capsaicin products are perceived as quite hot to the user, with repeated use, the patients adapt and perceived heat is diminished. Patients using both menthol and capsaicin-based products must to use care in keeping the cream, gel, or liquid away from the eye. It is prudent to use a disposable glove while applying these products to protect sensitive areas.

“These topical products can be quite useful in reducing pain and disability and provide an ongoing self-care, home regimen that can help with sleep and the ability to engage in exercise or activities such as gardening, which can benefit patients with chronic pain.” Pfefer said. “I was involved previously in a pilot study in which a topical menthol-based product was sparingly used on the forehead, temples and neck in patients with significant migraine-related disability.  In this group the patients were highly satisfied with and had moderate pain relief when using a topical menthol-based product.”

Over-the-counter topical menthol and capsaicin products are available in varying dosages and may be promising as a safe and effective adjunctive intervention for ongoing pain relief.  These non-addictive, topically-applied, easy-to-use, conservative options enable consumers to relieve pain without the detrimental side effects associated with oral analgesics or other medicine.

Original source can be found here.