Topical Analgesics

New formulations and dosage forms are available for the self-treatment of pain, and pharmacists can help patients choose the one that meets their needs.

For the treatment and management of musculoskeletal injuries and disorders, many patients commonly use nonprescription topical analgesics. Available in several different formulations, including gels, ointments, creams, lotions, sprays, and patches, and as single entity or combination formulations, these products may have local analgesic, anesthetic, antipruritic and/or counterirritant effects.¹

Counterirritants are approved by the FDA for the topical treatment of minor pains and muscle and joint aches, and are often used for the treatment of acute musculoskeletal injuries, such as simple backache, arthritis pain, strains, bruises, and sprains. In addition, these agents are also often used as adjuncts in the treatment of chronic musculoskeletal disorders.¹ Unlike other external analgesics, with counterirritants, pain relief results more from nerve stimulation than depression.¹ Counterirritants can be further categorized into 4 subgroups and can be used alone or in conjunction with oral analgesics when appropriate and warranted (Table 1).¹ External analgesic products may contain 1 or more of the following ingredients: methyl salicylate, camphor, menthol, methyl nicotinate, capsicum, and trolamine salicylate.

Topical heat therapy patches, such as ThermaCare (Wyeth), can also treat joint and muscle pain. ThermaCare patches, which are available in a variety of sizes that provide 8 to 12 hours of continual heat, work by using iron particles that react with air to give off heat.²

New Products

Some of the newest topical analgesic products on the market include Icy Hot Naturals (sanofi-aventis), which contains natural menthol; Icy Hot Power Gel; Icy Hot Medicated Spray; Tylenol Precise Pain Relieving Cream, which contains menthol and methyl salicylate; and Tylenol Precise Pain Relieving Heat Patches (McNeil PPC). Other new products include Bengay Cold Therapy (Johnson & Johnson), a menthol pain relieving gel, and Bengay Pain Relief and Massage Gel.

Counseling Points

Pharmacists should advise patients that nonprescription topical analgesics are intended to treat mild to moderate pain for no longer than 7 days unless otherwise directed by a physician.¹ Factors that may be considered when selecting a nonprescription topical analgesic include dosage form, cost, ease of use, odor, and the patient’s medical history, including possible allergies.¹ Patients who are taking anticoagulation therapy should be cautioned not to use topical products that contain salicylates (aspirin, methyl salicylate, and trolamine salicylate), as concomitant use has been associated with prolonged prothrombin time.¹

Patients should be counseled on the proper use of these products, which include using them as directed and only applying topical products to intact skin. Hands should always be washed after applying topical products and before touching the eyes or mucous membranes.

Tight bandages or occlusive dressing should not be applied to skin treated with counterirritants. Patients should also be cautioned not to use heating devices while using topical counterirritants.¹ If a patient experiences excessive redness or blistering of the skin, the product should be discontinued.

Patients should be advised to consult their primary health care provider if pain changes in severity or persists after 7 days of self-treatment.

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.

References

1. Wright E. Musculoskeletal injuries and disorders. In: Berardi R, Newton G, McDermott JH, et al, eds. Handbook of Nonprescription Drugs. 16th ed. Washington, DC: American Pharmacists Association; 2006:94-113.

2. ThermaCare product information. Pfizer Web site. www.thermacare.com/Faq.aspx. Accessed July 18, 2011.