Nephrotoxicity Profiles of Commonly Prescribed Antibiotics in Hospitalized Adult Inpatients: A Pharmacovigilance Cohort Across Tertiary Wards with Multivariable Risk Analysis

Acute kidney injury attributable to antibiotic exposure is a frequent yet frequently overlooked adverse event in hospital inpatients. We conducted a prospective pharmacovigilance cohort study across general medical, surgical, and intensive care wards at a tertiary hospital, enrolling 315 adult patients receiving antibiotics with documented nephrotoxic potential over 14 months. AKI by KDIGO criteria occurred in 68 patients (21.6%), with stage 1 in 41 (13.0%), stage 2 in 19 (6.0%), and stage 3 in 8 (2.5%). Incidence varied substantially by exposure: 14.3% with vancomycin alone, 27.8% with vancomycin and piperacillin-tazobactam in combination, 23.6% with aminoglycosides, and 38.5% with colistin. The risk gradient across baseline eGFR strata was steep, with combined exposures yielding AKI in over 40% of patients with baseline eGFR below 30. The strongest independent predictors were severe baseline renal impairment (adjusted HR 7.85), hypotension during exposure (HR 3.84), multiple concurrent nephrotoxin exposure (HR 3.18), and concurrent contrast administration (HR 2.42). Renal recovery to baseline at 60 days occurred in 92% of stage 1, 68% of stage 2, and 38% of stage 3 cases. The findings reinforce the case for structured renal-aware antimicrobial stewardship with dose-adjustment algorithms, hypotension surveillance, and avoidance of preventable combination exposures.