Medications are administered in multiple ways, utilizing every bodily orifice and further, by establishing temporary routes by intravenous (IV), intramuscular (IM) and subcutaneous (SQ) means. The chemical qualities of individual medications — such as solubility, acidity, metabolism and other factors — often limit the means by which they can be safely administered. After years of research, pharmacology companies began to market a number of different types of medications in patch form in the early years of the 21st century. High blood pressure, pain, anti-nausea and contraceptive medications can all be administered through the skin or dermis. Advantages of medications in patch form include less frequent administration, more consistently even levels of therapeutic drug amounts and less complicated drug regimens; disadvantages to medications in patch form include dermatologic side effects, special skin preparation before application and care of the patch after application.
Administration of medications in patch form takes place every one to three days, as opposed to many drugs requiring that many dosages per day, thus providing a significant advantage in terms of time and personnel needed for medication administration. Patch medications can also be utilized without complications in patients who are unable to take medications orally or who require medication to either be crushed or in liquid form. The use of anti-nausea medications in patch form is particularly appropriate as many patients are unable to tolerate any medication in their stomachs without vomiting. Patch medications are also helpful with patients for whom maintenance of an intravenous line would be difficult, such as chronically ill or elderly patients who wish to continue medical care in their home environments. Pain medications in patch form are also appropriate and safely administered to hospice patients whose appetites have passed and whose periods of consciousness are brief.
There are some disadvantages of medications in patch form. Some individuals can develop an allergic contact dermatitis at the site of the patch administration, either from the medication itself or from components of the skin adherence system. Either the patient or a responsible party must ensure that the patch is administered on the correct schedule and that the older patch is removed and disposed of properly. Prior to applying the patch to a chosen skin site, the area should be washed and dried gently to remove natural oils that might decrease the adherence of the patch and administration of the intended dose of medication while after removal of a used patch, the area should also be washed and dried gently to remove any remaining medication or patch glue. Areas with a great deal of body hair or perspiration, or those which are adjacent to heat sources — such as heating pads — should be avoided when applying medication patches.