Therapeutic Drug Monitoring; Measures the Amount of Certain Medicines in the Blood

 

Therapeutic drug monitoring (TDM) is testing that measures the amount of certain medicines in the blood. It is done to make sure the amount of medicine people are taking is both safe and effective. The monitoring involves not only measuring drug concentrations, but also the clinical interpretation of the result. This requires knowledge of the pharmacokinetics, sampling time, drug history, and the patient's clinical condition. The results are impacted by factors that affect pharmacokinetics and pharmacodynamics, such as age, gender, nutrition, pharmacogenetics, disease, pregnancy, body weight, disease, and drug-drug and food-drug interactions. It is done to make sure the amount of medicine people are taking is both safe and effective.

Therapeutic Drug Monitoring should be performed when the patient has achieved steady-state concentration, has changed drug therapy, or has had a change in response to treatment. It is a discipline of pharmacology and clinical biology that studies the concentration of therapeutic compounds in the blood. Its primary focus is on highly selective drugs with a narrow therapeutic spectrum, for example, drugs that are usually under or over-toxic to patients. It is measured using analyzers and computer programs. The primary objective of therapeutic drug monitoring is the monitoring of the concentration and levels of various compounds in the blood, to evaluate the effects and risks of new therapeutic agents and their potential use in medical practice.

The process also involves studying the effects of these drugs on human health and related risks. The primary component of therapeutic drug monitoring is the development and application of laboratory instruments for determining concentrations of selected therapeutic drugs in human plasma. The instruments used in clinical practice comprise analyzers that are based on different models of molecular biology processes and capable of measuring the concentration, mobility, and solubility of the analytics. Moreover, various assays based on parameters such as platelet-specific gravity, electrophoresis, blotting, and turbidity are also used in clinical practice. There are many ways of therapeutic drug monitoring.

One of them is the direct measurement of drug concentrations in a solution. This method is applied for the evaluation of the concentration of a specific drug against a standard curve and is very useful for measurements of concentrations over time. It can measure the concentration and recovery of administered agents. The recovery of drug concentrations is also important in providing reliable data for the toxicities of therapeutic drugs in human plasma. The biophysical technique is an alternative method of therapeutic drug monitoring and measures the concentration of a drug in a sample, usually serum or blood, at any time during the entire course of a patient's therapy. The blood monitoring of plasma drug concentration is another important and reliable clinical method of therapeutic drug monitoring.

The therapeutic range of medicine is the dosage range or blood plasma or serum concentration usually expected to achieve the desired therapeutic effect. Therapeutic drug monitoring helps in designing patient-specific dosage regimens; aids in enhancing the efficacy of drugs, reducing the toxicity of drugs, and for diagnostic purposes, by individualizing drug therapy. TDM is the clinical practice of measuring specific medicines at designated intervals to maintain a constant concentration in a patient's bloodstream, thereby optimizing individual dosage regimens.