Effect of losartan on the recoverability of renal function in anuric and oliguric patients with a solitary obstructed kidney: a double-blind randomized placebo-controlled trial.

Abstract

To assess the role of the angiotensin receptor blocker losartan on the recoverability of renal function after de-obstruction in patients with anuria and oliguria. This was a double-blind randomized placebo-controlled trial in anuric or oliguric patients with calcular obstruction of solitary kidney. Patients with an anomalous kidney or those with an American Society of Anesthesiology score of >3 were excluded. After relief of obstruction, patients were allocated to receive either losartan potassium 25mg or placebo for 3months. Serum creatinine (sCr) and renographic glomerular filtration rate (GFR) were measured at nadir and after 3months. Changes in sCr and renographic GFR were calculated by subtracting the values at nadir from those at 3months. Improvement, stabilization or deterioration of sCr and renographic GFR were defined as percentage increase or decrease from nadir ≥10%, while changes <10% were considered as stabilization. A total of 76 patients completed 3months of follow-up. Demographics and peri-operative data were comparable in the two groups. The median (range) sCr change was -1.05 (-1.8, 0.4) and -0.5 (-1.3, 0.1) mg/dL in the losartan and placebo, groups, respectively (P = 0.07). In the losartan group, renographic GFR had improved in 26 (59.1%) and deteriorated in six (13.6%) patients, while, in the placebo group, it had improved in eight (25%) and deteriorated in 10 patients (31.3%; P = 0.01). Losartan also enhanced renographic GFR improvement vs placebo by a median (range) of 6.9 (-9, 44) vs 1.4 (-10, 32) mL/min (P = 0.004). In patients with anuria and oliguria, losartan treatment contributes to renal function recoverability after relief of calcular obstruction of the solitary kidney.