Jasem therapeutic drug monitoring (TDM) method introduces a procedure for detecting drugs of abuse such as benzodiazepines, antidepressants, atypical antipsychotics, over-the-counter cold medicines as well as routinely used prescription drugs by follow up patients, in serum samples by LC/MS-MS. Jasem-TDM method facilitate the confirmatory of drugs implementing straightforward sample preparation (just protein precipitation) protocol. The list of analytes could be enlarged on customer request. LC-MS/MS is currently the best technique available for the correct quantification of therapeutic drug monitoring (TDM). According to customer needs, Jasem clinical toxicology kit is suitable to extend the drug list with new compounds.