Drugs affecting renal function: Coadministration of Biktarvy with drugs that reduce renal function or compete for active tubular secretion
may increase concentrations of FTC and tenofovir and the risk of adverse reactions.
Its production is relatively constant, and its excretion is primarily through glomerular filtration, although tubular secretion
can become important as serum creatinine rises in renal insufficiency.
glomerular filtration, active tubular secretion
and passive reabsorption.
However, creatinine also undergoes renal tubular secretion
. This process increases with declining glomerular filtration leading to the so-called "creatinine-blind range" between 50 and 90 mL/min/1.73 [m.sup.2], in which moderately decreased glomerular filtration is concealed by tubular secretion
Cisplatin is cleared by the kidney by both glomerular filtration and tubular secretion
and its concentrations within the kidney exceed those in blood suggesting an active accumulation of drug by renal parenchymal cells.
Tenofovir is excreted from the tubular cell by a combination of glomerular filtration and active tubular secretion
; the drug entry to the cell through the basolateral membrane involves organic anion transporters (OATs) mainly OAT1.
However, it has become evident that the creatinine concentration is far from ideal because it is significantly changed by other factors such as muscle mass, diet, gender, age and tubular secretion
. Serum concentration of Cystatin C is independent from muscle mass and gender.
Many drugs and their metabolites are excreted by the kidney by glomerular filtration, by tubular secretion
, or in some cases by both.
Among antidiabetic drugs, OCT2 is involved in proximal tubular secretion
of metformin, and OAT3 transports sitagliptin [9, 11].
The Icahn/Mount Sinai team reminds colleagues that drugs affecting tubular secretion
of creatinine also sway creatinine-based kidney function estimates.
In this aspect, the kidney performs three basic functions: glomerular filtration, tubular reabsorption, and tubular secretion
.The kidney function can be evaluated by a number of methods, including the assessment of urinary enzymes.
Also in dogs creatinine is excreted by glomerular filtration with only negligible renal tubular secretion
or extrarenal metabolism, however creatinine clearance is equivalently used as GFR.