The role of therapeutic Drug Monitoring

The role of Therapeutic Drug Monitoring

Therapeutic Drug Monitoring (TDM) plays a crucial role in ensuring the effectiveness and safety of certain medications that have a narrow therapeutic range. The primary goal of TDM is to tailor the individual dosage to each patient's specific needs. It helps healthcare professionals optimize drug efficacy, minimize the risk of toxicity, and improve overall patient outcomes. Common examples for TDM include antiseizure drugs, immunosuppressants, antibiotics, antipsychotics, and certain cardiovascular medications.

The Importance of Pharmacokinetic and Pharmacodynamics in TDM

Various laboratory techniques, such as immunoassays, chromatography, or mass spectrometry, are employed to accurately determine the drug concentration, typically in the patient’s blood. Once the drug concentration is determined, it is compared to therapeutic ranges or target concentrations, which have been established through extensive clinical research. These ranges define the optimal concentration window in which the drug exhibits maximum efficacy with minimal toxicity. Based on the measured drug levels and the patient’s clinical response, healthcare professionals can make informed decisions regarding dose adjustments, regimen modifications, or the need for alternative therapies.

Thus, the status quo focuses primarily on the pharmacokinetic profile (liberation, absorption, distribution, metabolism, and excretion) of the drug and the defined therapeutic range. However, since the therapeutic range varies between patients, the pharmacodynamic profile of a drug should also be considered. The pharmacodynamic profile of a drug refers to its molecular, biochemical, and physiologic effects or actions and is more relevant for side effects and drug interactions.

Breath TDM challenges the Status Quo

Singh et al., 2021, did not only report that the systemic concentration of both free and total valproic acid (VPA), a common antiseizure drug, can be measured in breath via distinct molecules. In addition, they also gained important insights on the pharmacodynamics with a simple breath test in real time. Several amino acid metabolic pathways were significantly different in patients suffering from severe side effects. Non-responders had a down-regulated tyrosine metabolism. Tyrosine is a precursor of dopamine, an important neurotransmitter that is known for its anti-epileptic action.

Overall, a simple breath test can uncover important pharmacokinetic and pharmacodynamic information, helping to better control and personalize vulnerable drug treatments.

DBI works on solutions for medical research and daily clinical practice by combining SESI-HRMS with advanced machine learning techniques for state-of-the-art breath analysis. Learn more about DBI’s technology & solution.

See the following video about breath research: