title: Skin tolerability of transdermal patches.
abstract: BACKGROUND
  Transdermal patch systems are an effective method of administering active ingredients through the skin, with considerable advantages over other drug delivery routes, for example, maintenance of constant plasma drug levels and avoidance of first-pass metabolism. However, repeated epicutaneous application may be associated with local skin reactions.
  
  
  METHODS
  This review addresses current issues regarding the effective/safe use of transdermal patch systems, and provides a critical analysis of the addition of 'skin-caring' ingredients to patch systems. Effective use of transdermal systems includes choosing an appropriate body area for application, maintaining regular skin care regimens before application and not replacing a patch in the same area (rotation) within 7 days. Another strategy, developed in an attempt to improve the tolerability of transdermal systems, is the addition of assumed 'skin-caring' ingredients (e.g., Aloe Vera) to patch systems. However, at present there is neither proof nor clinical evidence of any benefit. On the contrary, plant-derived ingredients might be associated with allergenic potential.
  
  
  CONCLUSIONS
  Transdermal systems are generally well tolerated; physicians must adequately inform patients of the most effective ways to use these formulations for maximum therapeutic benefit, while minimising local adverse events. Skin-caring agents, including Aloe Vera, cannot be recommended until well-controlled clinical trials with standardised extracts are available.
authors.affiliation: Martin Luther University Halle-Wittenberg, Department of Dermatology and Venereology, Ernst-Kromayer-Str. 5, D 06097 Halle (Saale), Germany. johannes.wohlrab@medizin.uni-halle.de
authors.forename: Johannes
authors.initials: J
authors.lastname: Wohlrab
authors.forename: B
authors.initials: B
authors.lastname: Kreft
authors.forename: B
authors.initials: B
authors.lastname: Tamke
mesh_terms: D000279:Administration, Cutaneous; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D004364:Pharmaceutical Preparations / Q000008:administration & dosage; D012867:Skin / Q000187:drug effects*
chemical_list: D004364:Pharmaceutical Preparations