October 2008

Discussion:

Emuprofen contains 10% ibuprofen, emu oil, and various other purported anti-inflammatory botanicals, including vitamin E, glucosamine sulfate, methylsulfonylmethane cetyl alcohol, Arnica montana extract, rosemary extract, green tea extract, boswella, and bromelain. The product is being marketed as an alternative to oral NSAIDs for numerous conditions, including arthritis, lower back pain, tendonitis, shin splints, shoulder and neck pain, ankle sprains, knee pain, foot pain, plantar fasciitis, carpel tunnel syndrome, and tennis elbow.

Topically administered NSAIDs are associated with decreased systemic absorption and fewer adverse events compared with their oral counterparts. This can be explained by the fact that topically administered NSAIDs do not undergo first-pass metabolism in the liver. Studies examining the pharmacokinetic and pharmacodynamic properties of topical ibuprofen have found that plasma concentrations of active drug ranged from 500 to 1,400 ng/mL after single or multiple applications. In contrast, plasma concentrations of oral ibuprofen at usual doses of about 400 mg were generally greater than 20,000 ng/mL. As a point of reference, systemic adverse events usually occur when plasma concentrations exceed 10,000 ng/mL.

Data suggest that topically administered NSAIDs are at least as effective as the orally administered ones. Higher plasma concentrations in areas of the skin around the source of the pain are usually seen with topically administered NSAIDs. Furthermore, plasma concentrations in the meniscus, cartilage, and tendon sheath are up to several hundred times greater after topical administration.3 It is theorized that direct absorption of the NSAID product through the skin into the tissues of the joint is responsible for these analgesic properties.

Emuprofen product also contains emu oil, which is made from the fat of the emu, a bird native to Australia. Emu oil has been used by Australians for thousands of years as a pain reliever for bone, muscle, and joint disorders. Emu oil is approximately 70% unsaturated fatty acids. The largest component is oleic acid—a monounsaturated fatty acid. Emu oil also contains about 20% linoleic (omega-6) acid and 1% to 2% linolenic (omega-3) acid. The omega oils contained in emu oil are thought to be responsible for its anti-inflammatory properties.

Patient information:

NSAIDs are among the most frequently prescribed prescription and OTC products worldwide and are responsible for approximately 25% of all adverse drug reaction reports. Of patients who use oral NSAIDs, 15% experience gastrointestinal adverse events. This is in part due to the fact that NSAIDs are most frequently used in patient populations already at an increased risk for experiencing gastrointestinal complications, such as the elderly or patients with rheumatoid arthritis. Topically administered NSAIDs offer the advantage of local, enhanced drug delivery to the affected areas with a decreased incidence of systemic adverse events like peptic ulcer disease and gastrointestinal hemorrhages. Adverse events associated with topically administered NSAIDs are primarily cutaneous in nature and include rash and itching at the site of application.

Patient instructions

  • For external use only.
  • Product should not be applied to the face, eyes, mouth, or genitalia.
  • Suggested use is three to four times per day, or as needed.
  • The product should be applied liberally and rubbed (massaged) into the skin. Rubbing the product into the skin increases its absorption.
  • The product should not be applied to areas of the skin that are open or have been damaged. Increased systemic absorption of topically administered medications can occur when they are applied to areas of the skin that are not intact.
  • The most common adverse events associated with topical NSAIDs are rash and itching at the site of application. Such cutaneous reactions occur in approximately 10% to 15% of patients.
  • Patients who are allergic to ibuprofen, emu oil, or any of the other botanicals in this product should avoid using Emuprofen.
  • Patients who are taking oral NSAIDs or products that could interact with NSAIDs should consult with their physician or pharmacist prior to using Emuprofen.
  • The product is not recommended for children younger than 12 years and should not be used during pregnancy or lactation.

—Ellen Whipple Guthrie, PharmD
Contributing writer