Focal glomerulonephritis and interstitial nephritis in methicillin-treated, heroin-related infective endocarditis.

A drug addict with staphylococcal endocarditis treated with methicillin, who developed massive proteinuria and acute nephritic syndrome is described. Discontinuation of methicillin therapy and appropriate antibiotic treatment of endocarditis led to clinical improvement, emphasizing the need to promptly discontinue potential nephrotoxic agents when abnormalities in renal function appear. The clinical course and results of renal biopsy studies suggest multiple causes of the renal lesions in this patient.