Medication products to pack for spring break travel

With the pounding that Old Man Winter gave much of the United States this season, many children and adults are no doubt looking forward to getting away to warmer climates over spring break. Appropriate planning for spring break travel — reserving travel arrangements, taking enough money and a few good books to read — is certainly beneficial. Packing suitcases with the right personal items, including medication products, is also important.

Insect repellents

Insect repellent products are likely to be one of the medical products spring break travelers will pack into their suitcases and carry-ons. These products are most needed for travel to areas where potentially dangerous infectious diseases can be transmitted by indigenous mosquitoes, including dengue fever, West Nile virus and malaria. Active ingredients found in insect repellent products are not regulated by the FDA, as are commonly used medicines. It is the Environmental Protection Agency that regulates active ingredients found in insect repellent products for efficacy and safety. Seven active ingredients are registered with the EPA as insect repellents (for direct application to skin). Most of these active ingredients are commonly available in various products, and include DEET (N,N-diethyl-m-toluamide), picaridin, oil of lemon eucalyptus, oil of citronella, and IR3535. Oil of lemon eucalyptus, oil of citronella and IR3535 are considered “biopesticide repellents,” as they are produced from natural materials. These ingredients may appeal to users who prefer to apply natural products. Some commercially available insect repellent ingredients are not required to be registered with the EPA, including peppermint, peppermint oil and soybean oil. Although these active ingredients have been previously evaluated for safety and found to possess minimal risk from use, the EPA has not evaluated them for effectiveness. The EPA is, however, currently re-evaluating this regulatory process.

DEET

DEET is likely the most commonly available and used insect repellent in the United States. The CDC said that DEET and picaridin have demonstrated greater efficacy than other insect repellent active ingredients. Although the active ingredients listed above that are registered with the EPA have all demonstrated some degree of efficacy, several factors can affect their clinical efficacy. These factors include: the species of mosquito that protection is desired against (some species are more aggressive than others); ambient temperature and amount of perspiration (eg, DEET efficacy decreases with increasing outdoor temperature); humidity; wind speed; and potential removal factors (such as swimming). DEET is often described in the lay and medical literature as the most effective insect repellent available, although few data are available from controlled, comparative trials. An important useful factor to describe insect repellent efficacy is duration of action, and this has been compared among insect repellent products with differing active ingredients in several published studies.

In 2002, Fradin compared several active ingredients from 16 products on 15 volunteers from repelling Aedes aegypti mosquitoes in a controlled laboratory environment. The three most effective products all contained DEET, in decreasing concentrations and duration of protection: 23.8%; 20%; 6.65%; and 301 minutes; 234 minutes; 112 minutes, respectively (all P,.05). One product tested contained soybean oil (Bite Blocker, HOMS) and provided 95 minutes of protection. Soybean oil, as described above, is not registered with the EPA as an ingredient with proven efficacy.

Two wristband products containing 9.5% DEET provided no protection (less than 1 minute). In a similar, but seemingly less controlled study, Consumer Reports magazine tested 18 products on four volunteers in 2006. The seven most effective products also contained DEET in decreasing concentrations and effectiveness. The longest-acting product contained 98% DEET and yielded a duration of protection of 12 hours, as compared with durations of 7.3 hours and 6.4 hours for products containing 34% and 30% DEET, respectively. Some data from other published studies indicate that the duration of protection from DEET may plateau at a concentration of 50%, although the uncontrolled study published in Consumer Reports refutes this. One product line, Ultrathon (3M), is advertised to provide up to 12 hours of protection (through slower-timed release of DEET), and contains 34% DEET. This product provided 7.3 to 9.5 hours of protection (depending upon the mosquito species tested) in the Consumer Reports study.

Adverse events

Although DEET has been shown to be an effective insect repellent, with long durations of effect from several products, some parents may be concerned with the potential for adverse effects, especially when DEET is on the skin for many hours. These concerns, however, are not supported by the medical literature. DEET has been used as a commercially available insect repellent for more than 50 years, and in this time (and considering how commonly it is likely been used), relatively few reports of significant adverse effects or toxicity have been reported. In a recent review of insect repellents, Katz describes 43 case reports of DEET toxicity during a 50-year period. Although several deaths due to DEET toxicity have been reported, all were caused by ingestion or inappropriate use. Most reported adverse effects have also been attributed to inappropriate use.

Several other reviews of DEET toxicity, such as reviews of poison center data, have also concluded that risk of toxicity from use of DEET is very low in children. Examples of inappropriate use of DEET identified in several studies include leaving DEET on skin overnight and direct application to the face (in which increased absorption may occur through mucous membranes). No data currently exist to identify a correlation between DEET concentration and risk of toxicity. In a recently published description of DEET-related adverse effects from a DEET Registry (1995-2001), 36 cases were assessed to be probably related to DEET use. Osimitz and colleagues concluded that the risk for serious neurological adverse effects from use of DEET is low. Thus, with appropriate use, DEET can be used safely and effectively as an insect repellent.

The AAP commented on the use of DEET in infants and children in 2003. The AAP states that DEET is the most effective insect repellent and recommends its use at concentrations of 10% to 30%. DEET can be used on infants as young as 2 months of age, according to the AAP. Some users may not like the oily feel that DEET can impart to skin once applied. DEET can also damage some clothing fabrics, including spandex, rayon and certain leathers. It may also damage some plastics (such as on watches and eyeglasses) and vinyl.

Picaridin has more recently become available in the United States and has been described as an effective, non-DEET insect repellent. It is available in several products at 7% and 20% concentrations. Duration of protection is approximately 4 to 5 hours with 20% concentration.

Sunscreens

Sunscreens may be the medical products most commonly used for many spring break travelers. As ultraviolet (UV) light is composed of UVA and UVB, protection from UVA (phototoxicity and photoaging) and UVB (sunburn) is important. Both UVA and UVB can produce DNA changes and skin cancer. The SPF (sun protection factor) commonly seen on sunscreen products refers to protection from UVB, not UVA. Several specific chemical agents are contained in sunscreen products. They function to absorb differing wavelengths of UV radiation (primarily UVB). Nearly all sunscreen products include more than one chemical agent. Products containing several ingredients, which together are capable of absorbing UV radiation in varying ranges (UVA and UVB), are referred to as broad spectrum and are preferred products. The FDA has recently proposed new regulations that would rate a product’s ability to provide protection against UVA radiation, besides protection from UVB, using a star rating system (1 star is “low,” 4 stars is “high”). The SPF acronym may also be altered to “sunburn protection factor,” listed adjacent to UVB, to indicate that the SPF reflects UVB sunburn protection. These proposed regulations are currently under consideration by the FDA.

Numerous sunscreen products are available to consumers. Many of these products are targeted toward children and include many dosage forms (lotions, foams, gels, sticks, creams, oils and lip balms). The AAP and American Academy of Dermatology recommend use of a sunscreen with a SPF rating of at least 15. Sunscreen products labeled as “broad-spectrum” should be used, as they would provide greater protection from UVA and UVB. Regardless of the specific sunscreen product used, its appropriate use is especially important to discuss with families. It is likely that many users of sunscreens do not use them properly. Sunscreens should be applied 30 minutes before sun exposure, as this allows time for the sunscreen to be absorbed.

Perhaps most important for users to understand and appreciate is the amount and frequency of application. Most sunscreen users do not apply enough sunscreen, nor apply it frequently enough. For an average-sized adult, at least 1 oz to 2 oz (2-4 tablespoons, or 1-2 shot glasses full) should be applied, and this amount should be re-applied every 2 to 4 hours while in the sun. Several studies have shown that decreased amount of sunscreen applied equates to decreased protection (eg, application of 50% of an appropriate amount of SPF 4 sunscreen results in protection equivalent to SPF 2).

Product choices

Product choice can be guided by SPF rating, broad-spectrum protection and price. Many products are marketed for use in children (eg, brightly colored lotions), and these products can be useful, as children may allow them to be used frequently. Prices of sunscreen products can vary widely. Many inexpensive, generic products can be used appropriately and effectively. Products that combine sunscreens and insect repellents together generally should not be used, as an insect repellent should not be applied as often as sunscreens. If sunscreens and an insect repellent are used concomitantly, sunscreen should be applied first, followed by application of the insect repellent. Insect repellents containing DEET often only need to be applied once. If the initial application has been on the skin for some time and insects continue to bite, another application is appropriate.

For more information:

• American Academy of Pediatrics. Follow safety precautions when using DEET on children. Available at: aapnews.aappublications.org/cgi/content/full/e200399v1. Accesed Feb. 17, 2011.
• Faurschou A. Br J Dermatol. 2007;156:716-719.
• Fradin MS. N Engl J Med. 2002;347:13-18.
• Insect repellents – which keep bugs at bay? Consum Rep. 2006;71:6.
• Katz TM. J Am Acad Dermatol. 2008;58:865-871.
• Osimitz TG. Regul Toxicol Pharmacol. 2010;56:93-99.
• Schalka S. Photodermatol Photoimmunol Photomed. 2009;25:175-180.

Edward A. Bell, PharmD, BCPS, is a Professor of Clinical Sciences at Drake University College of Pharmacy, Blank Children’s Hospital and Clinics in Des Moines, Iowa.

Disclosure: Bell reports no relevant financial disclosures.