Several different medications can be used for anesthesia. The most common brands used are Lidocaine or Septocaine. Lidocaine and Septocaine are used with epinephrine to prolong the effect of the anesthesia. Carbocaine is another anesthetic commonly used that does not contain epinephrine, which decreases the time of which the anesthetic will have its effect. Lastly, depending on the situation, nitrous oxide sedation may be used. All of these depend on the severity of the infection, the location of the tooth, and the patients health history. If the medicine does not suit you the most likely complications are anxiety attacks and possible heart palpitations. However, heart palpitations are unlikely.