Analgesic nephropathy - Is it caused by multi-analgesic abuse or single substance use?

Analgesic nephropathy is a slowly progressive renal disease, characterised by renal papillary necrosis. Recently, diagnostic criteria for this disease have been defined based on renal computed tomography scanning performed wi thout contrast. The observation of a decreased renal mass of both kidneys, combined with either bumpy contours or papillary calcifications, has been f ound to have high diagnostic specificity and sensitivity. However, the ques tion remains as to what kind of analgesics can cause analgesic nephropathy. In the majority of early reports about this condition, phenacetin was singl ed out as the nephrotoxic culprit. However, during the last decade the neph rotoxic potential of nonphenacetin-containing preparations has become appar ent. It is clear that people who abuse analgesics prefer combination analge sics containing 2 analgesics combined with caffeine and/or codeine. In cont rast, abuse of products containing only aspirin (acetylsalicylic acid) or p aracetamol (acetaminophen) is seldom described and associated renal disease is only occasionally reported. Experimental evidence of the nephrotoxicity of analgesic preparations is no t well established. The results of studies involving analgesic administrati on in animals remain contradictory. Clinical evidence linking high consumption of analgesic preparations with a nalgesic nephropathy is overwhelming. Most patients who admit to over-consu ming analgesics have taken preparation containing more than one compound. I n recent pears, it has become more apparent that preparations not containin g phenacetin also have the potential to cause nephrotoxicity manifesting as identical renal lesions. Further epidemiological evidence of the nephrotox ic potential of analgesic combinations has come from case-control studies p ublished during the last decade and from 2 prospective cohort studies. Effective prevention of analgesic nephropathy consists of the prohibition o f over-the-counter sales of preparation containing at least 2 analgesics as sociated with caffeine and/or codeine.