Final answer:
MDRD is used for estimating kidney function in drug dosing, but it has limitations for patients with some medical conditions. It estimates GFR using serum creatinine, which can vary among individuals and must be adjusted for factors such as age, weight, and comorbidities. Chronic kidney disease also affects drug pharmacokinetics, requiring personalized therapeutic drug monitoring. Option 3.
Step-by-step explanation:
The student's question relates to the routine use of MDRD (Modification of Diet in Renal Disease) for drug dosing. MDRD has been recommended for routine drug dosing; however, it has limitations for patients with some medical conditions. Determination of Glomerular Filtration Rate (GFR) is crucial for assessing how well the kidneys function and ensuring proper drug dosing to prevent toxic accumulations. The most accurate method for measuring GFR is the intravenous administration of inulin, which is cumbersome in clinical practice. Consequently, the GFR is often estimated by measuring serum creatinine levels. The MDRD formula takes into account creatinine levels, age, sex, and race to estimate kidney function. Option 3.
It is important to note that renal function can vary among individuals, and dosing may need to be adjusted due to factors like age, weight, genetic differences, comorbid diseases, and drug-drug interactions. Additionally, patients with chronic kidney disease (CKD) can experience reduced kidney function, which is classified by a GFR of <60 mL/min/1.73 m² for 3 months or more. This reduction can influence the pharmacokinetics of drugs, specifically those eliminated by the kidneys, necessitating tailored therapeutic drug monitoring (TDM) to avoid toxicity.