What should I know about lidocaine before using it?

If you are using prescription-strength lidocaine, especially in injection form, a doctor will carefully administer the medication. If you are using over-the-counter lidocaine, follow the directions. If you use lidocaine too much or too often, serious side effects may result from the medication being absorbed through the skin. Be careful if you are using lidocaine on a child because ingesting lidocaine can cause serious side effects. Because you temporarily cannot feel pain in the treated area, be careful not to injure yourself. Chewing gum and eating while numb in the mouth can cause you to hurt your mouth and cause pain once the numbing effect wears off. Because of the possible interactions, tell your doctor about any allergies or health problems you have or any medications you are currently taking.