Lidoderm is a classified as a local anesthetic, and it works by causing temporary numbness around the point of application. Lidoderm reduces discomfort and sharp, burning and aching pain caused by shingles, according to WebMD. Lidocaine is the generic name for Lidoderm.
Lidoderm patches are adhesive and measure 10 centimeters by 14 centimeters. Each Lidoderm patch contains 700 milligrams of lidocaine, as well as other inactive ingredients, according to RxList. Side effects include uneven heartbeats, drowsiness, tremors, seizure and blurred vision. Irritation, redness and swelling around area of application are also possible side effects. Allergic reactions include hives, difficulty breathing and swelling of the face, lips, tongue and throat.