Skin tolerability associated with transdermal drug delivery systems: an overview

As transdermal patches become more widely prescribed, it is important that clinicians understand: (a) the common causes of skin reactions with these medications; (b) how to minimize these reactions; and (c) how to manage the signs and symptoms. Here we review published data for skin reactions with patch medications approved within the past decade. Overall, the most common application site signs and symptoms appear to be localized redness (erythema) or itching, sometimes accompanied by swelling (edema). Typically, these are mild to moderate in severity, transient in nature, and occur in 20% to 50% of patients. Most are localized to the area of application, and resolve spontaneously within several days following patch removal. Discontinuations due to these types of event are infrequent, ranging from 1.7% to 6.8% in the 6-month trials reviewed here. Based on expert opinion, the majority of these skin reactions would be a form of irritant contact dermatitis, with infrequent cases of allergic contact dermatitis. These types of reactions usually cause minimal pain or discomfort to the patient, and are unlikely to be of medical concern. Signs and symptoms of irritant contact dermatitis may be minimized by rotation of the application site, careful removal of the patch, and appropriate use of moisturizers and topical corticosteroids. In conclusion, the potential advantages of transdermal patches usually outweigh any additional skin issues; however, further research into treatment and management strategies is required.