Which of the following best defines therapeutic drug monitoring (TDM)?

Therapeutic drug monitoring (TDM) is best defined as the practice of ensuring individualized drug dosing through measurement of drug levels. This approach is crucial because it allows healthcare providers to tailor medication regimens to the specific needs of each patient, taking into account factors such as drug metabolism, clearance rates, and potential drug interactions. By measuring the concentration of a drug in the blood, clinicians can assess whether a patient is within the therapeutic range, above it, or below it, which is vital for optimizing treatment efficacy while minimizing toxicity.

For many medications, particularly those with narrow therapeutic windows or significant inter-individual variability in pharmacokinetics, TDM helps in making evidence-based adjustments to dosing strategies. This individualized approach enhances the overall safety and effectiveness of drug therapy, as it ensures that patients receive the most appropriate doses based on their unique physiological responses.