Acute tubulointerstitial nephritis/drug induced acute kidney injury; an experience from a single center in Pakistan

Introduction: There is no information in literature specifically on the prevalence and clinicopathological characteristics of acute tubulointerstitial nephritis/drug induced acute kidney injury (AKI) from Pakistan. Objectives: We aim to report a series of cases from patients developing AKI after exposure to some medications or finding of interstitial nephritis on histopathology. Patients and Methods: This is an observational study of patients identified as having AKI after exposure to medications. AKI was defined according to RIFLE criteria and all patients fell from risk to loss category on arrival. On ultrasonography, all patients had normal size non-obstructed kidneys. Renal biopsy findings were consistent with tubule interstitial nephritis. Results: Mean age of patients was 36.41 ± 17.40 years. Among total of 155, 80 were male and 75 female. Regarding drugs, most common was exposure to aminoglycoside in 34 (22%) followed by use of non-steroidal anti-inflammatory analgesics in 28, contrast induced agents in 11. Renal biopsy was performed in 58 patients. In half of these, insulting agent was not known and in rest either multiple medications were ingested or there was denial to substance use or recovery was delayed despite discontinuation of responsible medication. Renal replacement therapy was required on arrival in 119/155 (hemodialysis = 115, peritoneal dialysis = 4) cases. Complete renal recovery was observed in 71%, while 7.7% expired during acute phase, partial renal recovery was seen in 15% and 5% disappeared after first discharge from the hospital. Conclusion: Tubulointerstitial nephritis may occur with many drugs of common use. Early and intensive efforts must be made to consider and then timely correct the injury to the kidney.