SAVANNAH, Ga. – Despite minor adverse skin reactions in 20%-50% of patients, the advantages of modern transdermal drug-delivery patches outweigh potential skin problems, according to a literature review.
The skin problems associated with transdermal patches are usually mild to moderate and rarely lead to treatment cessation, Dr. George T. Grossberg, St. Louis University, and colleagues reported in a poster presented at the annual meeting of the American Association for Geriatric Psychiatry.
A growing number of medications are now available in the transdermal patch form, including rotigotine for Parkinson’s disease, rivastigmine for Alzheimer’s disease, selegiline for major depressive disorder, and oxybutynin for overactive bladder (Adv. Ther. 2009;26:920-35).
Transdermal delivery offers several benefits over oral delivery, including smooth, continuous drug delivery, increased bioavailability, and reduced drug-drug interactions. Patches can be easily applied by the caregiver, and they provide a visual cue that the medication has been administered.
The researchers reviewed the literature on the subject from March 1999–March 2009 using PubMed, the U.S. National Institutes of Health online database of published medical research. The search identified 96 articles, 14 of which contained skin tolerability data from studies evaluating transdermal medications.
The most common symptoms were localized redness, itching, and edema. They lasted from a few days to a few weeks, and resulted in cessation of the treatment in only 1.7%-6.8% of patents in 6-month trials.
“These signs and symptoms were usually mild, localized and transient in nature, resolving spontaneously after patch removal,” Dr. Grossberg and his colleagues wrote. Skin reactions were typically either irritant contact dermatitis or, less commonly, allergic contact dermatitis. Most studies, however, did not classify the nature of the reaction or determine whether they were caused by the patch materials or the drug itself, investigators reported.
Irritant contact dermatitis, a common complications can be caused by damage to the skin during patch removal; blocking of sweat ducts; irritation to residual soap, lotion, etc.; or friction. It may be related to patch size, patch type, treatment duration, the environment, or the application site.
Allergic contact dermatitis occurs infrequently; it is typically caused by an immunologic reaction to the patch or the drug.
Treatment can include moving the patch; applying moisturizers or calamine lotion to reduce itching, or using corticosteroid creams to reduce allergic contact dermatitis. Sedative antihistamines can address itch-related sleep impairment, but they should be used with caution in the elderly and those at risk for falls, Dr. Grossberg and his colleagues warned.
“The advantages of transdermal medications over oral administration outweigh any potential skin issues, particularly if these are correctly managed and treated,” they concluded.
Novartis provided funding for the research.