N-Acetylcysteine in Patients With Leptospirosis

The goal of this clinical trial is to learn whether oral N-acetylcysteine (NAC) can reduce markers of kidney tubular injury, oxidative stress, and inflammation in adults with non-severe leptospirosis. The main questions it aims to answer are: * Does NAC result in a greater reduction in urinary kidney injury molecule-1 (KIM-1) levels from Day 1 to Day 5 compared with placebo? * Does NAC result in a greater reduction in serum reactive oxygen species (ROS) and C-reactive protein (CRP) levels from Day 1 to Day 5 compared with placebo? Researchers will compare NAC with a placebo to determine whether NAC produces greater changes in these biomarkers. Participants will: * Receive oral NAC 800 mg three times daily or a matching placebo for five days in addition to standard treatment for leptospirosis. * Have urinary KIM-1, serum ROS, and CRP measured before treatment and on Day 5.