Recently approved by the FDA, a lidocaine-tetracaine patch (Synera) has a built-in heating component that enhances the medication's analgesic effect. The patch consists of a thin, uniform layer of emulsified medication integrated with an oxygen-activated heating component. Applied to intact skin, the patch provides analgesia during venipuncture and superficial dermatologic procedures such as shave biopsies of skin lesions. Local skin reactions, including erythema, blanching, and edema, are the most common adverse reactions.