DAILY ACETAMINOPHEN USE LINKED TO CHRONIC RENAL DISEASE RISK

DAILY ACETAMINOPHEN USE LINKED TO CHRONIC RENAL DISEASE RISK, according to an article published in the May 11 issue of the New England Journal of Medicine. "We conclude that the long-term, regular use of phenacetin may increase the risk of chronic renal disease," Sandler et al. reported. "The long-term daily use of acetaminophen, the major metabolite of phenacetin, is associated independently with an increased risk of chronic renal disease." Researchers conducted a multicenter, case-control study of 554 patients with newly diagnosed (between 1981 and 1982) kidney disease and 516 patients selected randomly from the same area of central North Carolina. Kidney disease was defined as serum creatinine level of at least 1.5 mg/dL. Use histories of the analgesics phenacetin, acetaminophen and aspirin were obtained by telephone interview. The analgesic medications were classified according to the components in use during the early 1970s, before the removal of phenacetin from most OTC analgesic products. The study found that daily users of analgesics had significantly more renal disease than infrequent users (odds ratio 2.79; 95% confidence interval, 1.85-4.21), with the risk highest in daily users of phenacetin (odds ratio 5.11; confidence interval, 1.76-14.9 after adjustment for the effects of other analgesics). The risk of renal disease also increased with daily use of acetaminophen; after adjustment for the use of aspirin and phenacetin, the odds ratio was 3.21 (confidence interval 0.69-2.51). "Our data suggest a possible risk of renal disease associated with acetaminophen use that deserves more scrutiny," Sandler and his colleagues concluded. They found no increased risk in daily users of aspirin. Noting the $ 1 bil.-plus cost of the federal end-stage renal disease program, an editorial in the same NEJM issue suggests confirming the observations of Sandler et al. in other parts of the country where there is high analgesic use. "In view of the well described adverse effects of nonsteroidal anti-inflammatory drugs on renal function in certain high-risk patients, it would seem prudent to monitor these newer entrants into the OTC market as well," the editorial states. In the case of ibuprofen, the only NSAID currently approved for OTC use, FDA does require the package insert to specify known risk factors for renal dysfunction.