Lidocaine and prilocaine periodontal gel is used on the gums to cause numbness or loss of feeling during dental procedures. This gel basically deadens the nerve endings in the gum. Before using this medication, you need to tell your doctor if you have ever had any unusual or allergic reaction to lidocaine and prilocaine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. It is worth noting that Lidocaine and prilocaine may cause serious types of allergic reactions, including anaphylaxis, which can be life-threatening and require immediate medical attention. Therefore, you need to tell your dentist right away if you have a rash, itching, hoarseness, trouble with breathing or swallowing, or any swelling of your hands, face, or mouth after you receive the medicine. Because there are no human safety data on the topical use of this gel during pregnancy, lidocaine and prilocaine should only be used during pregnancy if clearly needed and if the benefits to the mother outweigh the risks to the child. And according to the manufacturers, caution should also be used when the gel in question is used during breast-feeding. For one, Lidocaine and probably prilocaine are excreted in breast milk.