Describe the role of the kidney in drug excretion, and the factors affecting this. Briefly outline how you would alter the dosing of gentamicin in a patient with renal impairment.
The main points candidates were expected to cover included a brief definition of renal
clearance followed by a description of the drug factors that affect this (filtration, secretion
and reabsorption), recognition that GFR and protein binding was important in the answer. A
brief description of gentamicin kinetics that affect dosing regimens and a statement that
dosing would be guided by calculated GFR and measured drug levels would round out a good
answer. Correct elaboration of the above factors was rewarded with additional marks.
Candidates failing this question submitted answers where concepts were randomly mentioned
with no attempt to integrate these into a cohesive answer that demonstrated an understanding
of the topic. Writing random words without examples or explanations did not demonstrate
sufficient understanding to be rewarded with marks. Again, many answers lacked sufficient
detail in the answer.
Miners, J. O., et al. "The Role of the Kidney in Drug Elimination: Transport, Metabolism and the Impact of Kidney Disease on Drug Clearance." Clinical Pharmacology & Therapeutics (2017).
Mahasen, Laila M. Aboul. "Evolution of the Kidney." Anatomy Physiol Biochem Int J 1(1) : APBIJ.MS.ID.555554 (2016)
Brater, D. Craig. "Measurement of renal function during drug development." British journal of clinical pharmacology 54.1 (2002): 87-95.
Levy, Gerhard. "Effect of plasma protein binding on renal clearance of drugs." Journal of pharmaceutical sciences 69.4 (1980): 482-483.
Regårdh, Carl G. "Factors contributing to variability in drug pharmacokinetics. IV. Renal excretion." Journal of Clinical Pharmacy and Therapeutics 10.4 (1985): 337-349.