Analgesic nephropathy: a significant cause of morbidity in the United States

Association of Opioids and Nonsteroidal Anti-inflammatory Drugs With Outcomes in CKD: Findings From the CRIC (Chronic Renal Insufficiency Cohort) Study

RATIONALE & OBJECTIVE

Safe analgesic choices are limited in chronic kidney disease (CKD). We conducted a comparative analysis of harm from opioids versus nonsteroidal anti-inflammatory drugs (NSAIDs) in CKD.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

3,939 patients with CKD in the Chronic Renal Insufficiency Cohort (CRIC) Study.

EXPOSURES

30-day analgesic use reported at annual visits.

OUTCOMES

A composite outcome of 50% glomerular filtration rate reduction and kidney failure requiring kidney replacement therapy (KRT), as well as the outcomes of kidney failure requiring KRT, hospitalization, and pre-kidney failure death.

ANALYTICAL APPROACH

Marginal structural models with time-updated exposures.

RESULTS

Participants were followed up for a median of 6.84 years, with 391 (9.9%) and 612 (15.5%) reporting baseline opioid and NSAID use, respectively. Time-updated opioid use was associated with the kidney disease composite outcome, kidney failure with KRT, death (HRs of 1.4 [95% CI, 1.2-1.7], 1.4 [95% CI, 1.1-1.7], and 1.5 [95% CI, 1.2-2.0], respectively), and hospitalization (rate ratio [RR], 1.7; 95% CI, 1.6-1.9) versus opioid nonusers. Similar results were found in an analysis restricted to a subcohort of participants reporting ever using other (nonopioid and non-NSAID) analgesics or tramadol. Time-updated NSAID use was associated with increased risk for the kidney disease composite (HR, 1.2; 95% CI, 1.0-1.5) and hospitalization (RR, 1.1; 95% CI, 1.0-1.3); however, these associations were not significant in the subcohort. The association of NSAID use with the kidney disease composite outcome varied by race, with a significant risk in blacks (HR, 1.3; 95% CI, 1.0-1.7). NSAID use was associated with lower risk for kidney failure with KRT in women and individuals with glomerular filtration rate<45mL/min/1.73m² (HRs of 0.63 [95% CI, 0.45-0.88] and 0.77 [95% CI, 0.59-0.99], respectively).

LIMITATIONS

Limited periods of recall of analgesic use and potential confounding by indication.

CONCLUSIONS

Opioid use had a stronger association with adverse events than NSAIDs, with the latter's association with kidney disease outcomes limited to specific subgroups, notably those of black race.

Non-contrast-enhanced computerized tomography and analgesic-related kidney disease: report of the national analgesic nephropathy study

Previous studies suggested that the non-contrast-enhanced computerized tomography (CT) scan is a highly reliable tool for the diagnosis of analgesic-associated renal disease. However, this issue has not been addressed in the US population. A total of 221 incident patients with ESRD from different regions of the United States underwent a helical CT scan and detailed questioning about drug history. Specific renal anatomic criteria were developed to determine whether a constellation of CT findings (small indented calcified kidneys [SICK]) is linked to analgesic ingestion. For approximating use before the onset of renal disease, only analgesic ingestion at least 9 yr before starting dialysis was considered relevant. Fifteen patients met the criteria for SICK. This represented 7% of the enrolled patients and approximately 1% of the total ESRD population. There was a significant increase in the estimated risk among patients with a history of heavy aspirin ingestion (odds ratio [OR] 7.4 [95% confidence interval (CI) 1.2 to 43] for > or =1 kg lifetime; OR 8.8 [95% CI 1.2 to 66] for > or =0.3 kg/yr). Total analgesic ingestion of > or =0.3 kg/yr also was significantly associated with SICK (OR 8.2; 95% CI 1.5 to 45). These findings were accounted for largely by combination products that contained aspirin and phenacetin (used by three patients with SICK), which are no longer available. In addition, the CT finding of SICK was present only in a minority of heavy analgesic users, yielding a sensitivity of 5 to 26%. Findings of SICK are infrequent in the US ESRD population and do not occur among a sufficient proportion of heavy analgesic users to render the non-contrast-enhanced CT scan a sensitive tool to detect analgesic-associated kidney injury.

A review of epidemiologic studies of nonnarcotic analgesics and chronic renal disease

The relationship of long-term and heavy exposure of nonnarcotic analgesics to the risk of chronic renal disease (CRD) has been the object of intensive clinical, pharmacologic, toxicologic, and epidemiologic research for 4 decades. The clinical evidence of an increased risk has been suggestive but inconclusive. The experimental evidence in animal models has been inconsistent, and in any case it cannot be generalized to humans. The epidemiologic evidence has been unsatisfactory for the most part: most of the early studies had severe methodologic limitations; moreover, they related mainly to phenacetin-containing drugs and did not have useful information on other analgesics. Since 1980, 9 analytical epidemiologic studies have attempted to confirm that a causal relationship exists between phenacetin or other analgesics and CRD. In the aggregate, despite methodologic flaws, this work suggests that excessive use of phenacetin-containing analgesics probably causes renal papillary necrosis and interstitial nephritis. In contrast, there is no convincing epidemiologic evidence that nonphenacetin-containing analgesics (including acetaminophen, aspirin, and mixtures of these two compounds) or that nonsteroidal antiinflammatory drugs cause CRD. Moreover, the nature of dose-response relationships, the types of renal disease possibly caused by analgesics, and the cofactors that might be related both to analgesic use and to the development of CRD in humans are still uncertain, and the pathologic mechanisms of analgesic-induced CRD in humans remain unclear. It may take many years before all the outstanding issues are settled. Until they are, as a matter of good clinical judgment it would be prudent to consider all analgesics as potentially nephrotoxic and, as much as possible, to avoid excessive, protracted use.

Case report: analgesic nephropathy: a soda and a powder

Analgesic nephropathy has long been considered a potentially preventable cause of renal disease. Early reports were described in patients who consumed analgesics containing phenacetin. In recent data, the removal of phenacetin from analgesic preparations resulted in a reduction in analgesic-induced end stage renal disease in Europe and Australia. However, a reduction in the incidence of analgesic nephropathy has not occurred uniformly, suggesting that phenacetin is not the sole cause. Current data raise concerns regarding adverse renal effects of acetaminophen and nonsteroidal antiinflammatory drugs. Aspirin taken alone may be of least concern. The diagnosis of analgesic nephropathy is suggested in subjects with chronic renal failure, a history of daily consumption of analgesic preparations, small bumpy kidneys, and renal papillary necrosis or chronic interstitial nephritis. However, the spectrum of disease may be changing, because these agents also may increase the risk of cardiovascular disease and chronic renal disease due to nephrosclerosis, glomerulonephritis, and diabetes mellitus. Potential pathogenetic mechanisms in analgesic nephropathy include direct cellular injury induced by analgesics, prostaglandin inhibition with reduction or redistribution of renal blood flow, and interesting new concepts regarding the role of caffeine in increasing oxygen demand and reducing oxygen supply in the medulla. The primary goal of therapy is discontinuation of analgesic consumption. Because of the association between analgesic intake and uroepithelial tumors, surveillance of patients for neoplasm is suggested.