RESUMEN
OBJECTIVE: To report a case of possible cloxacillin-induced acute tubulo interstitial nephritis (AIN). CASE SUMMARY: A 15-year-old male patient presented with hypertension, edema, lumbar pain, sterile pyuria, eosinophiluria (ten percent), and severe renal dysfunction three months after the ingestion of cloxacillin. A renal biopsy revealed diffuse edema and inflammatory infiltrate of the interstitium (five percent eosinophils). He received four sessions of peritoneal dialysis with dramatic improvement in urinary output and renal function. His biochemical parameters returned to normal values 21 days after admission, without the use of glucocorticosteroids. DISCUSSION: Published case reports on AIN induced by penicillin and related drugs are reviewed and compared. The role of interstitial edema in acute renal failure associated with drug-induced AIN is mentioned. CONCLUSIONS: AIN is a rare but significant complication of therapy with penicillin and related drugs. The clinical picture is similar for all of these drugs, but skin rash and fever are absent in AIN induced by cloxacillin and cloxacillin-related drugs. Dialysis improved the patient's urinary output and renal function. Beta-lactam antibiotics should be avoided in patients with cloxacillin-induced AIN.
