Regular analgesic intake and the risk of end-stage renal failure

The strength of the association between regular analgesic intake (RAI) and end-stage renal failure (EF) has been insufficiently established until now. A case-control study was conducted to estimate the relative risks (RR) of EF after RAI (defined as consumption of 15 or more analgesic doses per month for a continuous period of at least 1 year) for cumulative drug intake, single-ingredient analgesics, combinations, and specific compounds. The case group included all patients with EF undergoing renal replacement therapy in the area of West Berlin (1984-1986, n = 921). Control subjects, matched to cases by sex, age, and nationality, were selected from a group of patients in outpatient clinics. Matching was possible for 517 cases. The RR of EF after RAI of any analgesic was 2.44 (95% confidence interval: 1.77-3.39) and after RAI of combination drugs 2.65 (95% confidence interval 1.91-3.67). No significant increase was found, however, after RAI of single-ingredient analgesics. The RR after RAI of combination drugs and for the most preferred analgesic ingredients (phenacetin, paracetamol, acetylsalicylic acid, phenazones, caffeine) increased with dose. Furthermore, a dose-time-related RR after RAI of the longest used preparation was found. Thus, the results clearly show an increased RR of EF after RAI related to both dose and exposure time of mixed analgesic compounds, but not for the use of only single-ingredient analgesics.