Leptospirosis-associated acute kidney injury: penicillin at the late stage is still controversial

What is known and Objective: Some antimicrobial agents are active in vitro against Leptospiras. The use of penicillins at the late stage of leptospirosis is still controversial. We aimed to evaluate the use of penicillin in patients with leptospirosis-associated acute kidney injury (AKI). Methods: A retrospective study was conducted of patients with leptospirosis admitted to two hospitals in Fortaleza city, Brazil, between 1985 and 2008. AKI was defined according to the RIFLE and AKIN classifications. Patients were divided in two groups according to whether they were treated with a penicillin or not. Results: Two hundred and eighty-seven patients were included, with an average age of 36.8 +/- 15.6 years and mostly male (80.8%). One hundred and twelve patients (39%) received a penicillin. Patients treated with a penicillin were younger (32 +/- 14 years vs. 39 +/- 16 years, P = 0.0002) and had a shorter hospital stay (8.4 +/- 5.0 vs. 11 +/- 7.7 days, P < 0.0001). There was no difference in the onset of symptoms before hospital admission between the two groups (6.5 +/- 3.0 vs. 7.7 +/- 4.7, P = 0.33). Systolic blood pressure was lower in the penicillin group (111 +/- 21 vs. 119 +/- 22 mmHg, P = 0.04). AKI, need of dialysis and renal recovery at the time of hospital discharge were more frequent in patients who did not use a penicillin (P < 0.05). Mortality was similar in both groups (11.6% vs. 13.7%, P = 0.60). Conclusion: Treatment of leptospirosis with antibiotics, including the penicillin, remains controversial. The main benefit of using penicillin in the present study was a reduction in the length of hospital stay and fewer complications, such as AKI, but its use was not associated with a decrease in mortality. On balance of risks and benefits, we recommend the use of penicillin in late-stage leptospirosis.