Match each clinical scenario with the most accurate description of its expected primary pharmacokinetic alteration.
- Administration of an oral high-extraction ratio drug (e.g., propranolol) to a patient with advanced cirrhosisIncreased systemic bioavailability resulting from diminished first-pass extraction
- Measurement of serum phenytoin in a patient with end-stage renal disease and severe hypoalbuminemiaReduction in total serum drug levels despite a disproportionately elevated unbound fraction
- Administration of a highly lipophilic medication (e.g., diazepam) to a patient with morbid obesityExpansion of the volume of distribution leading to an extended elimination half-life
- Steady-state dosing of a renally cleared hydrophilic drug (e.g., cephalexin) in a patient in the third trimester of pregnancyLower steady-state plasma concentrations driven by augmented renal clearance
Answer
The correct matches pair cirrhosis with increased bioavailability due to bypassed first-pass metabolism; ESRD with decreased total drug concentration but elevated free fraction for phenytoin; morbid obesity with increased volume of distribution and prolonged half-life for lipophilic drugs; and third-trimester pregnancy with decreased steady-state levels due to augmented glomerular filtration.
Each clinical state alters a distinct, predictable pharmacokinetic variable: cirrhosis impairs first-pass metabolism, uremia disrupts protein binding, obesity expands the volume of distribution for lipophilic molecules, and pregnancy augments renal clearance.
Step-by-Step Solution
Key Concept
Pharmacokinetic alterations driven by specific physiologic or pathologic states dictate necessary therapeutic dose adjustments.
Estimated Time:1m 30s