Acute effects of gentamicin on glomerular and tubular functions in preterm neonates

Abstract

It has been reported that gentamicin causes natriuresis, magnesuria and calciuria in neonates. The aim of this study was to determine the acute effects of trough and peak levels of gentamicin on the values of serum creatinine (SCr), urine albumin/urine creatinine (UA/UCr), fractional excretion of sodium and potassium (FENa, FEK) and urine calcium/urine creatinine (UCa/UCr) in preterm neonates treated with gentamicin for suspected infection. Baseline levels of serum and urine Cr, Na and K and urine albumin and Ca levels together with trough and peak gentamicin levels were measured in 61 preterm neonates at the start of the therapy, on the day of the third gentamicin dose and 48-72 h after the cessation of the gentamicin therapy. Therapeutic trough and peak levels were recorded in 56 (91.8%) and 39 (63.9%) of the preterm neonates, respectively, whereas high trough (>2 mg/dl) and peak (>9.99 mg/dl) levels were recorded in five (8.1%) and 11 (18%) of the 61 preterm neonates, respectively. Trough and peak levels of gentamicin were positively correlated with SCr, UA/UCr, FENa, FEK and UCa/UCr values. The UA/UCr, FENa and UCa/UCr values recorded during treatment were statistically significantly different from sub-therapeutic, therapeutic and high peak gentamicin levels. Gentamicin was found to have a serum peak level-dependent microalbuminuric, natriuric and calciuric effect in preterm neonates. Based on these results, we suggest that when the monitoring of serum gentamicin levels is not possible, the monitoring of UA/UCr, FENa and UCa/UCr can be useful as a noninvasive alternative.

Evaluation of Novel Biomarkers of Nephrotoxicity in Two Strains of Rat Treated with Cisplatin

“…Therefore, in the absence of glomerular injury, which can cause an increased filtered load that can saturate proximal tubular reabsorption mechanisms resulting in frank proteinuria, the presence of small amounts of albumin in urine is considered indicative of reduced functional (reabsorptive) capacity in the proximal tubules (Russo et al 2007). Microalbuminuria, defined as a urinary albumin loss of 30-300 mg/24 hours, has also been reported in humans treated with cisplatin (Kern et al 2000;Koch Nogueira et al 1998), ifosfamide (Koch Nogueira et al 1998, methotrexate (Koch Nogueira et al 1998), and gentamicin (Tugay et al 2006). However, microalbuminuria may also occur in the setting of vigorous exercise, urinary tract infection, and dehydration .…”

Biomarkers of nephrotoxic acute kidney injury

“…Therefore, microalbuminuria may prove to be a useful marker of AKI and concomitant proximal tubular cell damage. Microalbuminuria has previously been reported with shortterm and long-term administration of nephrotoxic chemotherapeutics (Koch Nogueira et al, 1998;Kern et al, 2000) and antibiotics (Tugay et al, 2006). Microalbuminuria, however, may also occur in the setting of vigorous exercise, hematuria, urinary tract infection, dehydration, fever, and poor glycemic control.…”

Effect of intravenous gentamicin on urinary calcium excretion in newborns

“…Tugay et al showed gentamicin administration in preterm newborns increase urine calcium excretion from day 3 onwards. 15 …”

“…1,2 Some studies in newborns and animals have shown that gentamicin increases urinary calcium excretion. [11][12][13][14][15] Injection every 36-48 hours is a new recommendation for intravenous gentamicin treatment in newborns. 3 Following this new recommendation, there have been no further studies on the effects of extended gentamicin dosage on urinary calcium excretion in newborns.…”