Biocaine 2 % Injection rarely shows any side effects. However, you may experience injection site pain, redness, or swelling. Avoid receiving this medicine if you are allergic to it. It may make your reflexes slow or cause drowsiness sometimes. Biocaine 2 % Injection contains Lidocaine that is used to numb a specific area of your body to reduce pain and discomfort caused by surgical procedures such as needle punctures, insertion of a catheter or breathing tube, dental procedures, etc.