Research article

Analgesics use and ESRD in younger age: a case-control study

Fokke J van der Woude^{^ 1} , Lothar AJ Heinemann² , Helmut Graf³ , Michael Lewis⁴ , Sabine Moehner² , Anita Assmann² and Doerthe Kühl-Habich⁴

¹Nephrology, 5. Med. Klinik, Klinikum Heidelberg-Mannheim, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany

²Centre for Epidemiology & Health Research Berlin, Invalidenstr. 115, 10115 Berlin, Germany

³Neprologie, Krankenanstalt der Stadt Wien, Rudolfstifting, 3. Med. Abteilung, Juchgasse 25, 1030 Wien, Austria

⁴EPES Epidemiology, Pharmacoepidemiology and Systems Research GmbH, Wulfstr. 8, 12165 Berlin, Germany

author email corresponding author email^Deceased

BMC Nephrology 2007, 8:15doi:10.1186/1471-2369-8-15

Published:	5 December 2007

Abstract

Background

An ad hoc peer-review committee was jointly appointed by Drug Authorities and Industry in Germany, Austria and Switzerland in 1999/2000 to review the evidence for a causal relation between phenacetin-free analgesics and nephropathy. The committee found the evidence as inconclusive and requested a new case-control study of adequate design.

Methods

We performed a population-based case-control study with incident cases of end-stage renal disease (ESRD) under the age of 50 years and four age and sex-matched neighborhood controls in 170 dialysis centers (153 in Germany, and 17 in Austria) from January 1, 2001 to December 31, 2004. Data on lifetime medical history, risk factors, treatment, job exposure and intake of analgesics were obtained in a standardized face-to-face interview using memory aids to enhance accuracy. Study design, study performance, analysis plan, and study report were approved by an independent international advisory committee and by the Drug Authorities involved. Unconditional logistic regression analyses were performed.

Results

The analysis included 907 cases and 3,622 controls who had never used phenacetin-containing analgesics in their lifetime. The use of high cumulative lifetime dose (3^rd tertile) of analgesics in the period up to five years before dialysis was not associated with later ESRD. Adjusted odds ratios with 95% confidence intervals were 0.8 (0.7 – 1.0) and 1.0 (0.8 – 1.3) for ever- compared with no or low use and high use compared with low use, respectively. The same results were found for all analgesics and for mono-, and combination preparations with and without caffeine. No increased risk was shown in analyses stratifying for dose and duration. Dose-response analyses showed that analgesic use was not associated with an increased risk for ESRD up to 3.5 kg cumulative lifetime dose (98 % of the cases with ESRD). While the large subgroup of users with a lifetime dose up to 0.5 kg (278 cases and 1365 controls) showed a significantly decreased risk, a tiny subgroup of extreme users with over 3.5 kg lifetime use (19 cases and 11 controls) showed a significant risk increase. The detailed evaluation of 22 cases and 19 controls with over 2.5 kg lifetime use recommended by the regulatory advisors showed an impressive excess of other conditions than analgesics triggering the evolution of ESRD in cases compared with controls.

Conclusion

We found no clinically meaningful evidence for an increased risk of ESRD associated with use of phenacetin-free analgesics in single or combined formulation. The apparent risk increase shown in a small subgroup with extreme lifetime dose of analgesics is most likely an indirect, non-causal association. This hypothesis, however, cannot be confirmed or refuted within our case-control study. Overall, our results lend support to the mounting evidence that phenacetin-free analgesics do not induce ESRD and that the notion of "analgesic nephropathy" needs to be re-evaluated.