The general objective of this work was to study the use of general and local anesthetics in patients assisted by a public hospital. The specific objectives were: to detect the prevalence of the use of anaesthetics in hospitalized patients; to study all the ways in which this medication is used, comparing the data found with that in the scientific literature; to detect possible adverse reactions or known and unknown drug interactions among patients using this class of medication; to monitor the appearance of the main known adverse reactions of this class of medication; to record and notify the possible adverse reactions presented by patients using anaesthetics.