RT Book, Section A1 Nelson, Lewis S. A2 Hoffman, Robert S. A2 Howland, Mary Ann A2 Lewin, Neal A. A2 Nelson, Lewis S. A2 Goldfrank, Lewis R. SR Print(0) ID 1108438718 T1 Special Considerations T2 Goldfrank's Toxicologic Emergencies, 10e YR 2015 FD 2015 PB McGraw-Hill Education PP New York, NY SN 9780071801843 LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1108438718 RD 2024/03/19 AB Applying a xenobiotic to the skin to treat a systemic medical condition is not new. Ointments and other salves have been applied topically for thousands of years for the treatment of local and systemic diseases. During World War I, dynamite workers used nitroglycerin applied to their hatbands to prevent angina when they were away from work and no longer exposed to organic nitrates.31 Mustard seed plaster for chest congestion, releasing allyl isothiocyanate, and topical elemental mercurials for syphilis are other examples from the early 20th century.24 Over the past 30 years, an increasing number of medications have been formulated in transdermal delivery systems or patches to allow for systemic delivery of a xenobiotic. The first commercially available patch delivered scopolamine for motion sickness (1979), which was followed by nitroglycerin for chronic angina (1981) and then fentanyl for chronic pain management (1990). In the United States, the nicotine patch remains the most widely used transdermal delivery system both because of the high need for smoking cessation and its nonprescription availability. Certain medicinal xenobiotics, such as testosterone, can be administered topically without a patch as a spray or gel.18 Furthermore, nonmedicinals can be absorbed transdermally, as occurs with nicotine after direct exposure to moist tobacco leaf in patient with "green tobacco sickness" or with organic phosphorus pesticides.3