Abstract
Objective: Analyze studies regarding the use of local anesthetics, emphasizing the use of solutions in systemically compromised patients and the adverse reactions that may happen. Bibliographic Review: The discovery of substances that cause loss of sensitivity, caused a milestone for medicine and through this enabled the evolution of local anesthetics that would later be used in dental clinics. The choice of a local anesthetic is defined by the patient's systemic characteristics or complications that he has acquired during his life. The professional must take into account the time of the procedure, the toxicity that the anesthetic may have and its level of concentration. Systemic adverse reactions to local anesthetics are divided into three categories: toxic, psychogenic and allergic, according to the study done, allergic reactions by these local anesthetics can occur, and the dentist's lack of mastery over the subject can cause a complication to the patient. Final Considerations: It is important that the dental surgeon seeks continuous learning in order to have the best conduct during dental care.