Benzodiazepines (BZDs) represent an important class of compounds with a wide range of pharmacological effects and therapeutic uses. This project discusses the classification, mechanism of action, main pharmacological effects and adverse reactions of BZD. It also reports on the chemical synthesis and important physicochemical properties of BZD. The influence of modifying the chemical structure of BZD on drug potency, physicochemical characteristics, pharmacokinetics and drug metabolism was clarified. A problem of pharmacological abuse of BZD alone or in combination with other central nervous system (CNS) depressants has been examined. Forensic analysis of BZD in biological specimens for screening and confirmation of BZD abusers in forensic settings has been demonstrated, and the most important analytical techniques used for screening and measurement of BZD in forensic laboratories have been described. In this project, selected gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) spectra of diazepam (MS laboratory, Prof M. Abdel-Hamid) are selected for confirmation and quantification of diazepam. presented.1. Introduction: BZDs are a group of chemically synthetic compounds that were first synthesized in the late 1950s. BZDs share common chemical structural characteristics and their importance is related to their effect on the central nervous system. BZDs are known to act by depressing the central nervous system and show an important role when used for different purposes such as hypnotics, sedatives, antiepileptics and muscle relaxants. The appearance of benzodiazepines seemed to be very useful due to their powerful effect and low toxicity compared to barbiturates. Although they are relatively safe compounds, the drugs depend...... middle of paper......ad/201105_import/20110509050.pdf20. Fitzgerald, R., Rexin, D., & Herold, D. (1994). Detection of benzodiazepines: immunoassays versus gas chromatography/negative chemical ionization mass spectrometry. CLINICAL CHEMISTRY, 40(3), 373-380.21. Boeck, G., Samyn, N., Morris, M., & Wood, M. National Institute of Criminalistics and Criminology (NICC), Toxicology (2002). Development of a rapid and sensitive method for the quantification of benzodiazepines in human plasma by LC-MS/MS. Manchester, UK: MICROMASS.22. Jones, C., Wlans, F., Martinez, L., & Merritt, G. (1989). Benzodiazepines identified by capillary gas chromatography-mass spectrometry, with specific ion screening used to detect benzophenone derivatives. Clinical Chemistry, 35(7), 1394-1398. Figure 3. Structure-activity relationships of 1,4-benzodiazepines, adapted from (6)