To the Editor.
I find it disconcerting that diazepam, a drug that has been given to millions of people over a many-year period, should be labeled a nephrotoxin based on one case report that was not confirmed by either rechallenge or biopsy.1 The authors of this article fail to mention that renal failure with eosinophilia may be the result of atheroemboli,2 and that eosinophiluria is a nonspecific finding.3 While their patient did not have other features of atheroembolic disease (none were reported), at least his renal disease did occur after coronary angiography. Atheroembolic renal failure may progress over a period of weeks, and spontaneous improvement of renal function can occur. It is a diagnosis that is difficult to exclude in the absence of a renal biopsy. Given the long and benign track record of diazepam, I believe the odds strongly incriminate the angiographic procedure as the cause
Kirschbaum B. Diazepam Labeled Nephrotoxin Based on One Case. Arch Intern Med. 1987;147(10):1845-1849. doi:10.1001/archinte.1987.00370100159030