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.

Objectives: 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.

Materials And Methods: 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 25 mg or placebo for 3 months. Serum creatinine (sCr) and renographic glomerular filtration rate (GFR) were measured at nadir and after 3 months. Changes in sCr and renographic GFR were calculated by subtracting the values at nadir from those at 3 months. 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.

Results: A total of 76 patients completed 3 months 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).

Conclusions: In patients with anuria and oliguria, losartan treatment contributes to renal function recoverability after relief of calcular obstruction of the solitary kidney.