Final answer:
The purposes of TDM are to maximize therapeutic benefit and identify when the drug is outside the therapeutic range to prevent toxicity and optimize dosing.
Step-by-step explanation:
The purposes of Therapeutic Drug Monitoring (TDM) are to ensure that the drug dosage provides the maximum therapeutic benefit and to identify when the drug is outside the therapeutic range. Identifying when the drug concentration falls outside the therapeutic window is crucial to avoid both sub-therapeutic levels and potential drug toxicity. TDM involves the measurement of drug concentrations in plasma or serum and adjusting the dosage accordingly to individual patient needs, factoring in variables like age, weight, genetic polymorphism, co-morbid diseases, and drug-drug interactions. This personalized approach aims to optimize efficacy, minimize side effects, and reduce therapeutic costs. TDM is especially important for drugs with a narrow therapeutic range, significant variability in absorption and disposition among individuals, and a clear correlation between blood levels and therapeutic effects.