Transdermal drug delivery is a noninvasive method for delivering analgesics at a predetermined rate across the surface of the skin. There are a few common types of transdermal medications, like patches and gels. Patches containing medication mixed with a contact adhesive on one side are secured to the patient. The patient’s body heat triggers the release of the drug, and the medication is absorbed through the skin into the bloodstream and distributed throughout the body. Gels work much the same but are applied topically to the skin in the form of an ointment or cream.