Mar 22, 2016Topical Solutions
When an athlete has minor pain, topical analgesics can be a great solution. But how do you sort out the different choices and options?
By Dr. Brent Mangus & Dr. Dustin Mangus
Brent Mangus, EdD, ATC Ret., is Dean of the College of Education and Human Services at Texas A&M University-Commerce. He is also the co-author of Concepts in Athletic Training and Pharmacology Applications in Athletic Training and can be reached at: [email protected]. His son Dustin Mangus, MD, is a Fellow in cardiothoracic anesthesiology at Loma Linda (Calif.) University Medical Center.
The use of topical analgesics has become increasingly common in athletics during recent years. This is primarily due to the easy accessibility of these compounds as most can be bought over the counter (OTC). Many people also feel more comfortable using topical analgesics when compared to systemic medications, which may include more adverse side effects.
But the full effects of OTC topical analgesics depends on the type of injury, the athlete’s innate healing process and underlying pathology, and guidelines from the person supervising the application and use of the medication. On this last point, it is important to note that there may not be anyone supervising use. Many athletes decide to administer on their own without consulting an athletic trainer or physician, and this can be a problem.
Athletes need to understand that these medications are not magic elixirs that will cure whatever ails them. Each type has a specific purpose and the solution to another athlete’s injury may not be the right one for theirs.
Athletes should be reminded that contrary to popular belief and practice, they should not be indiscriminately applying a topical analgesic anytime they have some soreness after practice or a game. Instead, OTC topical analgesics should be used by athletes for temporary pain relief from musculoskeletal strains or sprains. Since many different variables exist that can enhance or reduce the effectiveness of these medications, it is important that athletic trainers have a basic understanding of the different products on the market so that they can make sure their athletes use them wisely and effectively.
HOW ANALGESICS WORK
OTC topical analgesics come in many different formulations, but they can be divided into two basic groups: salicylates and counterirritants. Salicylates are generally found in cream form or as ready-to-apply patches. Counterirritants are sold as creams, patches, wraps, gels, sprays, and balms.
Prescription-strength topical analgesics are also available. In certain cases, an athlete’s physician might find it appropriate to prescribe one of these stronger pain relievers for severe discomfort.
Salicylates are chemical compounds known to have analgesic properties. When included in a topical compound and rubbed on the skin, salicylates can provide localized pain relief. This is accomplished primarily by inhibiting the enzyme cyclooxygenase from producing prostaglandins and thromboxane, which act as messengers in the inflammatory process. In other words, salicylates help decrease inflammation.
Counterirritants, on the other hand, essentially create an abnormal sensation at the skin level that overrides pain impulses. Many counterirritants produce a sensation of temperature alteration in local tissues, making them feel hot or cold. These temperature signals distract the central nervous system by overriding other pain signals and creating a blocking mechanism. This is referred to as “excessive traffic confusion” in the central nervous system.
Think of it by picturing a number of freeways merging into one. All the vehicles want to get to the same place, but the smaller vehicles are typically able to pass the larger trucks, merge, and get to their final destination much sooner. This is similar to the way the central nervous system processes the variety of messages it constantly receives from receptors throughout the body. The temperature signal from the counterirritant overrides the pain signal from the injury.
There are many active ingredients listed on topical analgesic packages, which can be overwhelming or confusing for athletes. The following is a rundown of those they are most likely to see:
Methyl salicylate, also known as oil of wintergreen, is a close relative to the frequently administered oral form of salicylic acid, commonly referred to as aspirin, and helps to treat joint and/or muscle pain. Once absorbed into the body, methyl salicylate is converted into other active salicylate compounds, including salicylic acid. It is reported to be able to penetrate the skin without the need of a carrier to get the drug into the body. However, the exact mechanism of direct tissue penetration is currently unknown.
Methyl salicylates should not be used on multiple joints at one time as this increases the amount absorbed into the bloodstream and can result in toxicity. Use of this product should be limited to five consecutive days to limit absorption.
Trolamine salicylate is another topically administered salicylate marketed as a product that penetrates the skin to provide an analgesic effect, much like methyl salicylate. Manufacturers say that it is good for temporary relief of muscle soreness and recommend it for use after practice or a game.
Capsaicin is an extract from hot chili peppers and is marketed as both an analgesic and anti-inflammatory topical application. It targets the nerve endings just under the surface of the skin, stimulating them to send messages to the central nervous system that there is a slight burning sensation on the skin. Current studies suggest that capsaicin essentially defunctionalizes nociceptive fibers through a variety of biochemical pathways.
It has been reported that repeated application of capsaicin or application in high concentrations can cause desensitization and lead to long lasting sensory deficits. Applying a product containing capsaicin over multiple areas of the body for more than seven days can lead to the inhibition of sensory messages. If this practice is continued excessively, long term sensory deficits may arise.
Menthol is mainly derived from the mint plants (peppermint, wild mint, corn mint), but it is also produced synthetically. It produces a counterirritant effect by eliciting a cooling sensation through the inhibition of calcium currents in the neuronal membranes. It should be noted that there is no actual drop in skin temperature upon application. Rather, it activates specific receptors in the skin, which imitate a cooling sensation.
Camphor comes from the wood of the camphor laurel tree and is often included with menthol in OTC topical analgesics. Camphor appears to work as an analgesic through desensitizing local pain receptors. An athletic trainer may suggest that athletes alternate between camphor and capsaicin products to determine which is more effective for their specific injury.
Iron particles have a counterirritant effect and can often be found in heat patches. When exposed to air, iron undergoes a chemical reaction that, when applied to the skin, creates a feeling of heat radiating to the area covered by the patch.
The iron particles in these patches generally dissipate or become inactive after a few hours and the heating effect is dramatically reduced over time. However, if an athlete has sensitive skin or an allergic reaction to a heat patch, it is possible to cause damage to the skin.
Prescription medications come in cream form or ready-to-apply patches, but can only be prescribed by a physician who will monitor an athlete’s use. Included in this category are salicylates, local anesthetics, and non-steroidal anti-inflammatory drugs (NSAIDs), which have been shown to be effective in multiple reviews. Commonly prescribed NSAIDs include topical diclofenac, ibuprofen, ketoprofen, and piroxicam.
Though OTC topical analgesics are often used by older adults for single-joint osteoarthritis pain, athletes most commonly use them for handling the pain associated with a soft tissue injury like a sprain or strain. Strains often benefit from controlled tissue movement during the healing process, which can be painful. A topical analgesic can help dull that pain as the tissue remodels, and allow the athlete more movement so they can heal properly.
OTC topical analgesics are intended for use by athletes experiencing mild pain for up to seven days. If lengthier application is warranted, use should be prescribed and monitored by a physician.
Topical analgesics may be most helpful if applied when the injury is close to being fully healed. Once the athlete is within five days of a return to competition, the combination of the massaging action from applying a topical analgesic cream, gel, or balm may be helpful. If done correctly, massaging can increase blood flow to the injured area and assist with the proper alignment of collagen fibers that have been laid down in the healing process.
WORDS OF CAUTION
Athletes should be constantly reminded that a topical analgesic shouldn’t be used in order to allow them to return to play before an injury is healed. It should only be used to help them manage pain during the healing process, if warranted.
Some athletes may want to use topical analgesics before competition to produce a “warming” sensation in their muscles, creating a pseudo feeling that their muscles are ready to work. This can be dangerous for athletes, especially those who play sports that require explosive bursts or ballistic movements by the muscles. Mentally, the athlete may believe their muscles are warmed up and they are ready to compete when they’re feeling a masked effect from the counterirritant.
For example, soccer players often rub a counterirritant onto their inner thighs to warm up tight groin muscles as a part of their pregame routine. But these only provide the feeling of heat and do little to warm the muscle tissue. Few players who have experienced groin pulls during a match ever reported a reduction in pain from the use of counterirritants. Most, if not all of the soccer players using these products to relieve tightness in their groin muscles, indicated the use was more helpful for “mental” pain relief than the actual relief of muscle tightness.
Football players have also been known to apply a counterirritant before practice to help the muscles feel warm and stay warm throughout the practice. Some apply so much of the product that there is a visible layer on the skin before they wrap the area with elastic wrap. There are many anecdotal reports of damage to the skin–sometimes severe–when this much product is applied, covered, then left on the skin for hours.
A heating device should never be used in conjunction with a topical analgesic either. If one were to malfunction or be left on the skin too long, severe damage could result to the skin since the appropriate pain messages may not be relayed to the brain.
Finally, the warnings on the packaging ring true. Topical treatments should not be used if the skin is not healthy. Any damage to the skin can allow a foreign substance to enter the body, and toxicity can result. And if any blistering or abnormal reaction to application occurs, the athlete should immediately stop use and consult a physician before further action is taken or another topical treatment is initiated.
When recommending the use of topical analgesics, keep in mind that these products are not always well understood by athletes. But when implemented correctly and at the right times, they can be helpful for pain management. As an athletic trainer, you can help athletes use them the right way, and for the right reasons.
To view references for this article, go to: www.Training-Conditioning.com/references.