Elevated serum creatinine levels in three patients treated with phenacemide

Three adolescent patients with severe seizure disorders were treated with phenacemide. All three patients showed elevated serum creatinine and normal blood urea nitrogen values while on phenacemide. Simultaneous urea and creatinine clearance studies performed on each patient demonstrated normal urea clearances and decreased creatinine clearances. Inulin clearance performed in one patient was normal. The medication was discontinued in two of the patients because of co-existing neutropenia. Serum creatinine values returned to normal after phenacemide treatment was terminated. The elevation in serum creatinine values with phenacemide appears to be dose related, reversible, and unrelated to impairment of glomerular filtration.