{"id":12124,"date":"2019-09-06T18:26:41","date_gmt":"2019-09-06T16:26:41","guid":{"rendered":"https:\/\/www.eurekakit.com\/en\/?page_id=12124"},"modified":"2025-06-13T12:51:11","modified_gmt":"2025-06-13T10:51:11","slug":"clinical-pharmacology-lc-ms","status":"publish","type":"page","link":"https:\/\/www.eurekakit.com\/en\/clinical-pharmacology-lc-ms\/","title":{"rendered":"Therapeutic Drug Monitoring LC\/MS"},"content":{"rendered":"

Therapeutic Drug Monitoring LC\/MS<\/h2>\n

Pharmacological treatments and their side effects can have an impact on the patients\u2019 safety or life\u2019s quality. Specifically, the so called ADME (absorption, distribution, metabolism, and excretion) of the drug can be highly influenced by the genetics, environment and administration of other drugs due to co-morbidities. Therefore, in some cases the treatment with a fixed drug dose can turn out risky for patients\u2019 health. For this reason, the Monitoring of a drug therapy which is optimized for a specific case is necessary.
\nOn one hand, this can be particularly needed for drugs that present a narrow therapeutic range, which can be easily exceeded causing many toxic effects and\/or increasing drugdrug interactions (DDIs) (Tuzimski, et al. 2020_review). On the other hand, if the drug concentration is lower than the safety ranges the pharmacological activity might not occur.
\nIn the light of this, Therapeutic Drug Monitoring (TDM) is a strategic way to \u201cadjust\u201d the treatment and the dose based on patient\u2019s clinical case (Kuhlin_cMSpec_2018). In clinical practice, several matrices can be used for TDM: whole blood, serum, plasma, dried blood spots, oral fluid. In serum, the binding between protein and drug can occur so that only a smaller quantity remains unbound and, consequently, it is responsible for the therapeutic effect. Nevertheless, for particular patients it may be necessary to monitor the total drug concentration (Tuzimski, et al. 2020_review).
\nMainly, drug metabolism take place at the hepatic level, thorough Cytochrome P-450 (CYP450) (for review, Patel 2016).
\nUpon metabolism the drugs are usually inactivated. However, in some cases they give rise to drug metabolites which are responsible of pharmacological activity (active metabolites). Such effect can be even higher than the one of the parent drugs. Many drugs or substances might enhance or reduce the enzymatic activity of CYP450 leading to DDIs that may result in higher toxicity or lower pharmacological activity of one of the drugs (Ref. Drug Metabolism by Jennifer Le, https:\/\/www.msdmanuals.com).
\nDDIs might also reduce the formation of pharmacologically active metabolites (Eliasson et al.).<\/p>\n

Here some clinical scenarios of when TDM is required are reported:<\/p>\n