Analgesic nephropathy

Proprotein convertase subtilisin/kexin type 6 (PCSK6) is a likely antigenic target in membranous nephropathy and nonsteroidal anti-inflammatory drug use

Drugs are an important secondary cause of membranous nephropathy (MN) with the most common drugs associated with MN being nonsteroidal anti-inflammatory drugs (NSAIDs). Since the target antigen in NSAID-associated MN is not known, we performed laser microdissection of glomeruli followed by mass spectrometry (MS/MS) in 250 cases of PLA2R-negative MN to identify novel antigenic targets. This was followed by immunohistochemistry to localize the target antigen along the glomerular basement membrane and western blot analyses of eluates of frozen biopsy tissue to detect binding of IgG to the novel antigenic target. MS/MS studies revealed high total spectral counts of a novel protein Proprotein Convertase Subtilisin/Kexin Type 6 (PCSK 6) in five of the 250 cases in the discovery cohort. A validation cohort using protein G immunoprecipitation, MS/MS, and immunofluorescence detected PCSK6 in eight additional cases. All cases were negative for known antigens. Ten of 13 cases had a history of heavy NSAID use with no history available in one case. The mean serum creatinine and proteinuria at kidney biopsy were 0.93 ± 0.47 mg/dL and 6.5 ± 3.3 gms/day, respectively. Immunohistochemistry/immunofluorescence showed granular staining for PCSK6 along the glomerular basement membrane, and confocal microscopy showed co-localization of IgG and PCSK6. IgG subclass analysis in three cases revealed codominance of IgG1 and IgG4. Western blot analysis using eluates from frozen tissue showed IgG binding to PCSK6 in PCSK6-associated but not in PLA2R-positive MN. Thus, PCSK6 may be a likely novel antigenic target in MN in patients with prolonged NSAID use.

Interstitial Nephritis: Wherefrom, Wherein, and Whereto

Abnormalities of the renal interstitium were noted early while identifying chronic kidney disease in 1827; however, interest in glomerular and vascular lesions was then distracted from their further study. As a complication of scarlet fever, interstitial lesions attracted attention in 1859 and came to be defined as acute interstitial nephritis in 1898. The chronic form of interstitial nephritis was traditionally attributed to pyelonephritis until the advent of kidney biopsy in the 1950s, when interstitial lesions were recognized as an independent primary cause of chronic kidney disease from studies of analgesic nephropathy and vesico-ureteral reflux. The term tubulointerstitial nephritis was introduced in 1963 and promoted to denote the role of the tubules in the pathogenesis and the clinical presentation of interstitial nephritis as tubular dysfunction. Studies since then have established that fibrotic tubulointerstitial nephritis lesions correlate best with the severity and progression of kidney diseases independent of their etiology.

Provider-directed analgesia for dental pain

INTRODUCTION

Extraction of impacted molar teeth is a common procedure performed by oral surgeons and general dentists, with postoperative pain being a significant adverse event post-surgery. If mismanaged, pain can lead to complications that impact oral and systemic health. The current scourge of the opioid epidemic has ushered in a new era of provider-directed analgesic (PDA) therapy in dentistry.

AREAS COVERED

This article provides an in-depth review on the major pharmacological and therapeutic properties of established and alternative analgesics used to manage dental pain.

EXPERT OPINION

Substantial evidence-based literature shows combination of a non-steroidal anti-inflammatory drug (NSAID; e.g. ibuprofen) and acetaminophen provides superior pain relief than single-agent or combination opioid regimens. However, there are clinical scenarios (e.g. severe pain) when short-course opioid prescription is appropriate in select patients, in which a 2-3-day treatment duration is typically sufficient. Alternative agents (e.g. caffeine, gabapentin, phytotherapies), typically in combination with established agents, can mitigate postoperative dental pain. Some evidence suggests preemptive therapies (e.g. corticosteroids, NSAIDs) reduce amounts of postsurgical analgesic consumption and might lessen opioid prescription burden. In summary, this comprehensive review provides an opportune update on the evolving landscape of pharmacotherapy for acute postsurgical dental pain, informing best practices for PDA in the dental setting.

Pre-transplant donor-specific HLA antibodies and risk for poor first-year renal transplant outcomes: results from the Swiss Transplant Cohort Study

The aim of this study was to analyze first year renal outcomes in a nationwide prospective multicenter cohort comprising 2215 renal transplants, with a special emphasis on the presence of pre-transplant donor-specific HLA antibodies (DSA). All transplants had a complete virtual crossmatch and DSA were detected in 19% (411/2215). The investigated composite endpoint was a poor first-year outcome defined as (i) allograft failure or (ii) death or (iii) poor allograft function (eGFR ≤25 ml/min/1.73 m² ) at one year. Two hundred and twenty-one (221/2215; 10%) transplants showed a poor first-year outcome. Rejection (24/70; 34%) was the most common reason for graft failure. First-year patient's death was rare (48/2215; 2%). There were no statistically significant differences between DSA-positive and DSA-negative transplants regarding composite and each individual endpoint, as well as reasons for graft failure and death. DSA-positive transplants experienced more frequently rejection episodes, mainly antibody-mediated rejection (both P < 0.0001). The combination of DSA and any first year rejection was associated with the overall poorest death-censored allograft survival (P < 0.0001). In conclusion, presence of pre-transplant DSA per se does not affect first year outcomes. However, DSA-positive transplants experiencing first year rejection are a high-risk population for poor allograft survival and may benefit from intense clinical surveillance.

Renal risk profiling in newly diagnosed hypertensives in an urban population in Nigeria

Introduction

Hypertension is a cause and consequence of chronic kidney disease globally. The other factors that work in concert with hypertension to cause CKD are yet to be clearly elucidated. Studies have identified proteinuria, dyslipidemia, obesity, smoking and family history of CKD as renal risk factors. Due to the high morbidity and mortality associated with occurrence of CKD including the enormous financial burden involved in its management, the knowledge of prevention and understanding of the risk factors for development of CKD is highly essential. Therefore, Identifying well defined risk factors that display strong graded association with the occurrence and progression of CKD can help in elucidating potential targets for disease modification.

Objective

The aim of this study was to determine the prevalence of renal risk factors and their impact on kidney function in newly diagnosed hypertensive Nigerians.

Methods

This was a case control study of two hundred and fifty newly diagnosed hypertensive Nigerians recruited from two contiguous hospitals in an urban setting in south western Nigeria. Another group of two hundred and fifty apparently healthy age and sex matched normotensive Nigerians in the same community were recruited as controls.

Results

Seventy (28%) of the newly diagnosed hypertensives had estimated glomerular filtration rate of less than 60ml/min, while 42.4% and 18.8% of the subjects and the controls had microalbuminuria respectively. The newly diagnosed hypertensives had significantly higher prevalence of analgesic use (86.4% versus 41.6%, p < 0.001), alcohol consumption (20.8% versus 12%, p = 0.008), use of canned salted food (18.8% versus 8.4%, p= 0.001) and central obesity (36.1% versus 26.8%, p= 0.025) compared to controls.

Conclusion

There is a significant occurrence of modifiable renal risk factors in newly diagnosed hypertensives and this offers a platform for instituting preventive strategies in the community.

Long-term adverse effects of paracetamol - a review

Paracetamol (acetaminophen) is the most commonly used drug in the world, with a long record of use in acute and chronic pain. In recent years, the benefits of paracetamol use in chronic conditions has been questioned, notably in the areas of osteoarthritis and lower back pain. Over the same period, concerns over the long-term adverse effects of paracetamol use have increased, initially in the field of hypertension, but more recently in other areas as well. The evidence base for the adverse effects of chronic paracetamol use consists of many cohort and observational studies, with few randomized controlled trials, many of which contradict each other, so these studies must be interpreted with caution. Nevertheless, there are some areas where the evidence for harm is more robust, and if a clinician is starting paracetamol with the expectation of chronic use it might be advisable to discuss these side effects with patients beforehand. In particular, an increased risk of gastrointestinal bleeding and a small (~4 mmHg) increase in systolic blood pressure are adverse effects for which the evidence is particularly strong, and which show a degree of dose dependence. As our estimation of the benefits decreases, an accurate assessment of the harms is ever more important. The present review summarizes the current evidence on the harms associated with chronic paracetamol use, focusing on cardiovascular disease, asthma and renal injury, and the effects of in utero exposure.

A case of acetaminophen-induced acute tubulointerstitial nephritis in adult

We report a case of allergic acute tubulointerstitial nephritis (TIN) induced by acetaminophen in a 48-year-old Japanese man with no past medical history. Two days after receiving the non-steroidal anti-inflammatory drug (NSAID) loxoprofen for left shoulder pain, he developed cold symptoms such as fever and sore throat. He then took a 300 mg dose of acetaminophen three times a day and a 100 mg dose of minocycline hydrochloride twice a day for 7 days. Because there was no improvement in his symptoms, he consulted a local clinic again, where blood tests revealed renal insufficiency, and he was, then, referred to our hospital for evaluation of kidney function. Renal biopsy revealed acute TIN, and Ga-67 scintigraphy showed diffuse uptake in bilateral kidneys. A drug-induced lymphocyte stimulation test (DLST) was positive for acetaminophen and negative for loxoprofen and minocycline. Based on these findings, we made a diagnosis of acetaminophen-induced TIN. We treated the patient with three courses of semi-pulse steroid therapy, after which his fever went down, and his serum creatinine level recovered from 2.09 to 1.43 mg/dL. Although we medical doctors think that therapeutic dose of acetaminophen retains high safety, it is important to keep in mind that acetaminophen can cause allergic acute TIN.

Pro: Heat stress as a potential etiology of Mesoamerican and Sri Lankan nephropathy: a late night consult with Sherlock Holmes

Epidemics of chronic kidney disease are now recognized in Central America, Mexico, India and Sri Lanka, and there is also some evidence that similar epidemics may be occurring in the USA, Thailand and elsewhere. A common denominator for each location is manually working outside in extremely hot environments. Here we review the evidence that the primary etiology may be heat stress related to repeated subclinical or clinical acute kidney injury that eventually manifests as chronic kidney disease. In some aspects, the disease may manifest as subclinical heat stroke, subclinical rhabdomyolysis or a subclinical tumor lysis syndrome. While toxins could be involved, it would be difficult to attribute this as a main mechanism, given the wide range of occupations and geographic regions manifesting this disease. While some of the epidemics may be due to better reporting, we believe the most important reasons are increasing heat extremes (heat waves) coupled with hydration with sugary or, less commonly, alcoholic beverages.

Epidemiology, diagnosis, preoperative evaluation and prognostic assessment of upper-tract urothelial carcinoma (UTUC)

PURPOSE

Upper-tract urothelial carcinoma (UTUC) is a relatively uncommon disease with limited available evidence on specific topics. The purpose of this article was to review the previous literature to summarize the current knowledge about UTUC epidemiology, diagnosis, preoperative evaluation and prognostic assessment.

METHODS

Using MEDLINE, a non-systematic review was performed including articles between January 2000 and February 2016. English language original articles, reviews and editorials were selected based on their clinical relevance.

RESULTS

UTUC accounts for 5-10 % of all urothelial cancers, with an increasing incidence. UTUC and bladder cancer share some common risk factors, even if they are two different entities regarding practical, biological and clinical characteristics. Aristolochic acid plays an important role in UTUC pathogenesis in certain regions. It is further estimated that approximately 10 % of UTUC are part of the hereditary non-polyposis colorectal cancer spectrum disease. UTUC diagnosis remains mainly based on imaging and endoscopy, but development of new technologies is rapidly changing the diagnosis algorithm. To help the decision-making process regarding surgical treatment, extent of lymphadenectomy and selection of neoadjuvant systemic therapies, predictive tools based on preoperative patient and tumor characteristics have been developed.

CONCLUSIONS

Awareness regarding epidemiology, diagnosis, preoperative evaluation and prognostic assessment changes is essential to correctly diagnose and manage UTUC patients, thereby potentially improving their outcomes.

Common Analgesic Agents and Their Roles in Analgesic Nephropathy: A Commentary on the Evidence

An association between non-opioid analgesic agents and chronic kidney disease has long been suspected. The presumed development of chronic renal impairment following protracted and excessive use of non-opioid analgesia is known as analgesic nephropathy. Many clinicians accept analgesic nephropathy as a real entity despite the paucity of scientific evidence. This narrative review aims to summarize the literature in the field. The weight of available observational literature suggests that long-term ingestion of paracetamol and combination mixtures of aspirin and paracetamol are likely to contribute to chronic renal impairment. However, there is no convincing data to implicate non-steroidal anti-inflammatory drugs or aspirin monotherapy in the development of analgesic nephropathy. In the absence of high-level evidence, while controversy persists, it may be prudent for physicians to consider all non-narcotic analgesics to be nephrotoxic with long-term use.

Chemical-Induced Nephropathy: A Review of the Renal Tubulointerstitial Lesions in Humans

It is almost ironic that one of the major organs that serves to maintain the “internal milieux” by secretion of various toxic agents, can itself become injured in the process. The pattern of morphologic renal injury is nonspecific and can involve any of the components of the kidney, although the injury and subsequent morphologic changes are most commonly noted in the tubules and/or interstitium. Of course, unless the drug/toxin is commonly or regularly noted to be associated with tubular and/or interstitial injury, the association of the drug with the renal changes may be missed and the correlation may not necessarily identify causation. For example, if a drug is associated with a renal injury in a given individual, it may be quite difficult to prove that the drug is the cause of the injury. This scenario is somewhat reminiscent of the test question—is it “true-true-related,” or “true-true-unrelated”? Sometimes it is only by the accrual of a great many examples or correlations, and or dissection of the pathophysiology, can it be shown that the drug is directly related to the observed morphologic (and subsequent clinical) injury. Renal changes induced by chemicals can affect the tubules, interstitium or both. This review of chemically induced nephropathy in humans considers acute tubular necrosis, interstitial nephritis , and tubulointerstitial nephritis or nephropathy. Because the tubules and the interstitium are so intimately related, injury to 1 of these 2 components may eventually lead to injury of the other, resulting in tubulointerstitial disease.

Analgesic Nephropathy–-A Painful Progression

One of the dreaded complications of long term analgesic intake is nephrotoxicity characterized by chronic interstitial nephritis and papillary necrosis. Much of the literature of its epidemiology dates back to 1960s and its impact on present day society is not well documented. Non steroidal anti inflammatory agents reduce pain by blocking prostaglandin generation. Prostaglandins have renal vaso dilatory effects in states of volume depletion to counteract the vasoconstrictive pressor hormones. Earlier analgesic tablets contained a mixture of aspirin, phenacetin and caffeine. Phenacetin and its metabolites have nephrotoxic potential and incidence of analgesic nephropathy was brought down in countries where it was banned. The concentration of phenacetin and its metabolite acetaminophen is increased at the tip of renal papilla due to counter current concentrating mechanism of the loop of henle. These are potent oxidants leading to cell injury due to lipid peroxidation, though their effects are normally counterbalanced by anti oxidant glutathione. Glutathione deficiency at the medulla can be precipitated by co ingestion of aspirin. The exact dose of analgesics which needs to be ingested is unclear but a daily ingestion of 5–8 tablets over 5 years results in clinical nephrotoxicity. The histopathology is one of chronic interstitial nephritis with renal fibrosis. Clinically the patient presents with polyuria, asthenia and anemia. The diagnosis is suspected in a patient with progressive chronic kidney disease without proteinuria. CT imaging of the kidneys show irregular scarred kidneys with papillary calcification and necrosis. Recently, COX-2 inhibitors are promoted as renal safe drugs, but may not be so given the multiple case reports of renal toxicity in post marketing surveys. The treatment of analgesic nephropathy includes discontinuation of offending drug, protein restricted diet, control of blood pressure and statins. In conclusion analgesic nephropathy is a preventable cause of chronic kidney disease and both the patients and treating physicians should be mindful of the potential nephrotoxcity of nonsteroidal anti inflammatory agents when administered for prolonged periods without monitoring renal function.

Non-steroidal anti-inflammatories and the development of analgesic nephropathy: a systematic review

BACKGROUND

Analgesic nephropathy (AN) is chronic renal impairment as a direct consequence of chronic heavy analgesia ingestion. An association between non-steroidal anti-inflammatory agents and chronic kidney disease (CKD) has long been suspected. Despite ample observational data obtained in recent decades the relationship remains uncertain. This systematic review intends to summarize the available literature and to define the role of non-steroidal anti-inflammatories in the natural history of AN.

METHODS

We conducted a systematic literature search for articles describing the association between non-steroidal anti-inflammatory abuse and renal insufficiency. No restriction was placed on publication date, but papers were limited to English language, observational design, and human studies.

RESULTS

Nine articles met our inclusion criteria and were discussed in this review. This includes 5 cohort studies and 4 case-control trials, with a combined population of 12,418 study subjects and 23,877 controls. Eight of the nine reports failed to identify any increased risk of chronic renal impairment with heavy non-steroidal anti-inflammatory consumption. Study methods were heterogeneous and the overall quality of data was relatively poor.

CONCLUSION

A relationship between non-steroidal anti-inflammatory medicines and the development of CKD has never been proven. Based on the available scientific evidence non-steroidal anti-inflammatory agents do not appear to be implicated in the pathogenesis of AN.

Pain and Kidney Function Decline and Mortality: A Cohort Study of US Veterans

BACKGROUND

Chronic pain is a common condition in the general population. However, large epidemiologic studies examining the role of pain in the deterioration of kidney function, development of chronic kidney disease, and risk for death are lacking.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A nationally representative cohort of 2,360,056 US veterans with baseline estimated glomerular filtration rates (eGFRs) ≥ 60mL/min/1.73m(2), followed up from October 2004 to September 2006.

PREDICTOR

4 pain categories were compared: none (score, 0), mild (1-4), moderate (5-6), or severe (≥7).

OUTCOMES

eGFR decline (determined by eGFR slope) and combined incident eGFR<60mL/min/1.73m(2) or all-cause death.

MEASUREMENTS

We examined the pain management pattern and association of reported pain with (1) rapid eGFR decline and (2) a composite outcome of incident eGFR<60mL/min/1.73m(2) or all-cause death using logistic regression and Cox models adjusted for baseline eGFR, demographics, comorbid conditions, cardiovascular risk factors, and depression.

RESULTS

∼60% of veterans reported pain of any severity during the baseline period. The most commonly prescribed analgesics were opioids. In a dose-response relationship, veterans reporting moderate or severe pain had a higher risk for faster eGFR decline compared with those reporting none (ORs of 1.11 [95% CI, 1.09-1.14] and 1.17 [95% CI, 1.13-1.21] for moderate and severe pain, respectively). In combined analyses, veterans reporting moderate or severe pain both had 30% higher risk of the combined outcome (incident eGFR, 60 mL/min/1.73 m(2) or death) compared with those reporting none (HRs of 1.30 [95% CI, 1.28-1.31] and 1.30 [95% CI, 1.28-1.32] for moderate and severe pain, respectively).

LIMITATIONS

Lack of granular data regarding type and location of pain.

CONCLUSIONS

We observed a high prevalence of pain and analgesic prescription in the US veteran population with normal eGFRs. Pain was associated with a higher incidence of eGFRs<60mL/min/1.73m(2), faster kidney function decline, and higher mortality.

Nonsteroidal antiinflammatory drugs, cyclooxygenase-2, and the kidneys

Nonsteroidal antiinflammatory drugs (NSAIDs) are one of the most commonly used classes of medications in the world, which function by inhibiting the cyclooxygenase (COX) enzymes and downregulating the inflammatory pathway. COX enzymes are constitutively expressed in the kidneys and function to maintain a homeostatic environment in terms of maintaining the glomerular filtration rate, blood pressure, sodium, water, and osmotic regulation. When the COX enzymes are inhibited by NSAIDs, a multitude of renal and vascular complications occur. This article aims to enlighten primary care physicians of the complications that arise with NSAIDs from a renal perspective and to present some management strategies.

Adverse drug reactions in dental practice

Adverse reactions may occur with any of the medications prescribed or administered in dental practice. Most of these reactions are somewhat predictable based on the pharmacodynamic properties of the drug. Others, such as allergic and pseudoallergic reactions, are less common and unrelated to normal drug action. This article will review the most common adverse reactions that are unrelated to drug allergy.

Therapeutic dose of acetaminophen as a possible risk factor for acute kidney injury: learning from two healthy young adult cases

Acetaminophen overdose can lead to severe liver and kidney failure; however, the risk of therapeutic doses in healthy individuals causing acute kidney injury (AKI) is less clear. We herein describe the cases of two young adults with renal biopsy-proven acute tubular necrosis under a therapeutic dose of acetaminophen. The first patient exhibited mild reversible renal insufficiency, whereas, in the second case, the patient demonstrated a slightly increased serum creatinine level and enlarged kidneys and the administration of contrast media and antibiotics may have worsened the renal dysfunction, leading to the need for temporal hemodialysis. Physicians should be aware of the risk of acetaminophen causing AKI and avoid administering other nephrotoxic agents in such cases.

Double-Blind, Randomized Comparison of the Analgesic and Pharmacokinetic Profiles of Controlled- and Immediate-Release Oral Oxycodone in Cancer Pain Patients

Thirty patients with cancer pain completed a double-blind crossover study comparing controlled-release (CR) and immediate-release (IR) oxycodone. In open-label titration (2 to 21 days), these patients were stabilized on IR oxycodone qid. They were then randomized to double-blind treatment with CR oxycodone q12h or IR oxycodone qid for 3 to 7 days followed by crossover at the same daily dose. Mean (+/- SD) pain intensity (0 = none to 10 = severe) decreased from a baseline of 6.0 +/- 2.2 to 2.7 +/- 1.1 after titration with IR oxycodone dosed qid. Pain intensity remained stable throughout double-blind treatment: 2.7 +/- 1.9 with CR oxycodone and 2.8 +/- 1.9 with IR oxycodone. Acceptability of therapy and pain scores correlated with plasma oxycodone concentrations for each interval and were similar for both medications (IR and CR oxycodone). Adverse events were similar for both formulations. Following repeat dosing under double-blind conditions, oral CR oxycodone administered q12h provided analgesia comparable to IR oxycodone given qid.

Chinese herbs nephropathy and Balkan endemic nephropathy: toward a single entity, aristolochic acid nephropathy

Chinese herbs nephropathy (CHN) and Balkan endemic nephropathy (BEN) are chronic tubulointerstitial renal diseases associated with urothelial carcinoma. The clinical expression and pathological lesions observed at different stages of CHN and BEN are strikingly similar. Both have been linked to exposure to aristolochic acid (AA), a powerful nephrotoxin and human carcinogen. Jelaković et al. present molecular epidemiological evidence relating urothelial carcinoma in patients with BEN to dietary exposure to AA. It is time to abandon the terms 'CHN' and 'BEN' and introduce 'aristolochic acid nephropathy' to cover both clinical conditions.

Regular use of nephrotoxic medications is an independent risk factor for chronic kidney disease--results from a Chinese population study

BACKGROUND

Prescription drug abuse is an important global health concern. Our previous survey in Beijing indicates that nephrotoxic medication use is independently associated with chronic kidney disease (CKD).

METHODS

In the present study, the study population consisted of participants from our previous survey with a confirmed history of nephrotoxic medication use. Nephrotoxic mediations included three antipyretic analgesics (58.2%) and three Chinese traditional medicines containing aristolochic acids (CTM-AAs, 47.3%). Prevalence of CKD (defined by presence of albuminuria and/or reduced estimated glomerular filtration rate) as well as markers of tubular injury was analysed, and compared with 109 age- and sex-matched controls.

RESULTS

The prevalence of CKD was higher among medication users compared with controls, which was 18.3% and 8.5%, respectively. Among participants with medication use without CKD, markers of tubular injury including N-acetyl-β-d-glucosaminidase, transferrin and α(1)-microglobulin, were present in 26.6%. CKD was associated with CTM-AA use (cumulative AA-I dose > 0.5 g, OR = 5.625, P < 0.05) and antipyretic analgesic use (cumulative dose > 2.0 kg, OR = 3.848, P = 0.063) in a dose-dependent manner. Albuminuria and tubular injury persisted among CTM-AA users, but not among analgesic users after cessation of drug.

CONCLUSIONS

Our study suggests that education about rational analgesic use and CTM-AA banning may constitute an effective CKD prevention strategy.

Effects of 2-bromoethanamine on TonEBP expression and its possible role in induction of renal papillary necrosis in mice

Chronic analgesic abuse has been shown to induce severe renal injury characterized by renal papillary necrosis (RPN), an injury detectable at late stage. While direct toxicity of the drug may exist, the molecular mechanisms underlying analgesics induction of RPN remain unknown. A major limitation to study the pathogenesis of RPN is the required chronic exposure before detection of injury. Here, we employed 2-bromoethanamine (BEA) to simulate rapid papillary toxicity using inner medullary collecting duct (IMCD3) cells. Although exposure to 10μM BEA had no effect on cellular viability under isotonic conditions, a 50% loss in cell viability was observed in the first 24 h when cells were subjected to sublethal hypertonic stress and nearly complete cell death after 48 h suggesting that BEA exerts cytotoxicity only under hypertonic conditions. Because TonEBP is a transcription factor critical for cell survival during hypertonic conditions, we undertook experiments to examine the effect of BEA on TonEBP expression and activity. Exposure of cells to 10μM BEA resulted in a substantial reduction in TonEBP protein expression after 24 h. In addition, TonEBP was not translocated to the nucleus in BEA-treated IMCD3 cells under acute hypertonic stress for transcription of target genes essential for osmolyte accumulation. Finally, we found a substantial decrease in TonEBP expression in medullary kidney tissues of mice injected with a single ip dose of BEA. Our data suggest that TonEBP is a potential target for BEA leading to the process of papillary necrosis in the settings of hypertonic stress.

Pain management: Part 1: Managing acute and postoperative dental pain

Safe and effective management of acute dental pain can be accomplished with nonopioid and opioid analgesics. To formulate regimens properly, it is essential to appreciate basic pharmacological principles and appropriate dosage strategies for each of the available analgesic classes. This article will review the basic pharmacology of analgesic drug classes, including their relative efficacy for dental pain, and will suggest appropriate regimens based on pain intensity. Management of chronic pain will be addressed in the second part of this series.

Mechanisms of drug-induced nephrotoxicity

Drug-induced nephrotoxicity is a common complication of several medications and diagnostic agents. It is seen in both inpatient and outpatient settings with variable presentations ranging from mild, reversible injury to advanced kidney disease. Manifestations of drug-induced nephrotoxicity include acid-base abnormalities, electrolyte imbalances, urine sediment abnormalities, proteinuria, pyuria, hematuria, and, most commonly, a decline in the glomerular filtration rate. The mechanisms of drug-induced nephrotoxicity may differ between various drugs or drug classes, and they are generally categorized based on the histological component of the kidney that is affected. Aminoglycoside antibiotics, radiocontrast media, conventional nonselective nonsteroidal anti-inflammatory drugs, and selective cyclooxygenase-2 inhibitors, amphotericin B, and angiotensin-converting enzyme inhibitors have been frequently implicated. This chapter reviews the clinical presentation and basic mechanisms of drug-induced nephrotoxicity.

The association of codeine, macrocytosis and bilateral sudden or rapidly progressive profound sensorineural deafness

CONCLUSIONS

Codeine shows a similar association with profound deafness to other opiates. Good cochlear implant outcomes suggest a sensory disorder. Although macrocytosis could be due to confounding factors, the lack of other consistent findings may signify a vascular pathology.

OBJECTIVES

To describe a series of patients identified as codeine users after referral for cochlear implantation.

PATIENTS AND METHODS

This was a retrospective case series review. Patients were identified by the senior audiologist. Information regarding mode of onset of deafness, past medical history, drug and alcohol history, investigations and audiological outcomes following cochlear implantation was collected from hospital records and patient questionnaires.

RESULTS

Ten patients were included in the study. All patients had taken codeine phosphate and paracetamol in combination for several years, usually at greater than recommended daily dose. All patients presented with sudden or rapidly progressive bilateral deafness. All patients had a significant macrocytosis at the time of deafness (mean cell volume (MCV): mean 115 fL; range 105-132 fL). No other investigation was consistently abnormal. Four patients had a history of alcoholism. Seven patients had abnormal liver function tests. Patients usually performed well with cochlear implants (CUNY sentence scores without lip reading >90% in 9 of 10 patients).

Over-the-counter analgesic use

Chronic analgesic nephropathy, particularly chronic interstitial nephritis and renal papillary necrosis, results from daily use for many years of mixtures containing at least two analgesics and caffeine or dependence-inducing drugs. Computed tomography scan can accurately diagnose this disease even in the absence of reliable information on previous analgesic use. The occasion to moderate regular use of aspirin and nonsteroidal anti-inflammatory drugs is without renal risk when renal function is normal. Paracetamol use is less clear although the risk is not great. The continued use of non-phenacetin-combined analgesics with or without nonsteroidal anti-inflammatory drugs is associated with faster progression toward renal impairment. As long as high-risk analgesic mixtures are available over the counter, analgesic nephropathy will continue to be a problem.

Melamine nephrotoxicity: an emerging epidemic in an era of globalization

Recent outbreaks of nephrolithiasis and acute kidney injury among children in China have been linked to ingestion of milk-based infant formula contaminated with melamine. These cases provide evidence in humans for the nephrotoxicity of melamine, which previously had been described only in animals. The consequences of this outbreak are already severe and will likely continue to worsen. Herein we summarize the global impact of the melamine milk contamination, the reemergence of melamine-tainted animal feed, and potential mechanisms of melamine nephrotoxicity. Large-scale epidemiologic studies are necessary to further characterize this disease and to assess its potential long-term sequelae. This epidemic of environmental kidney disease highlights the morbidity associated with adulterated food products available in today's global marketplace and reminds us of the unique vulnerability of the kidney to environmental insults. Melamine is the latest in a growing list of diverse potentially toxic compounds about which nephrologists and other health-care providers responsible for the diagnosis and management of kidney disease must now be aware.

The epidemiology of drug-induced disorders: the kidney

The epidemiology of drug-induced renal disorders is a complex topic. Drug-associated nephrotoxicity accounts for 18 - 27% of all acute kidney injury cases in US hospitals. Medications can affect all aspects of the kidney, and drugs that are associated with renal dysfunction are used commonly in clinical practice. The article reviews six major mechanisms of drug-induced renal dysfunction as well as lists the major medications involved. NSAIDs, aminoglycosides, amphotericin B and calcineurin inhibitors are just some examples of drugs that contribute to renal dysfunction. The medical community must be aware of patient risk factors for nephrotoxicity, as well as the drug's inherent nephrotoxic potential, when prescribing and administering medications.

Non-phenacetin analgesics and analgesic nephropathy: clinical assessment of high users from a case-control study

BACKGROUND

A recent large-scale case-control study on analgesic nephropathy (SAN) [1] found no increased risk of end-stage renal disease (ESRD) in users of combined or single formulations of phenacetin-free analgesics. In a subgroup of 22 high users, however, a dose-dependent increased risk was found, which raised the question if these patients presented or not with analgesic nephropathy (AN).

METHODS

The individual questionnaires of this subgroup of high users were reviewed, and the total lifetime intake of different types of analgesics was calculated. For evidence of AN, the following data were considered: (1) the amount and type of analgesics consumed, (2) the cause of ESRD, as diagnosed by the nephrologist in charge of the patient and (3) renal imaging and other relevant laboratory data.

RESULTS

This group of ESRD patients consumed on average 7.8 kg of antipyretic analgesics (range 30.8-2.7 kg) over an average of 21.5 years (range 35-6 years). Single analgesics were exclusively used by 12 patients (54.5%) and combined analgesics by 5 patients (22.7%), while 5 patients used both. None of the patients was diagnosed as having AN, and a review of the questionnaires did not disclose evidence suggestive of AN. The possibility that, irrespective of AN, the analgesic (ab)use contributed to the progression of existing renal diseases cannot be answered in the absence of well-defined criteria. The data supporting the existence of such an analgesic-associated nephropathy (AAN) are, however, not consistent and most likely due to confounding by indication.

CONCLUSION

In a group of ESRD patients with high use of non-phenacetin analgesics, no evidence of AN was found. There is no evidence that (ab)use of analgesics or NSAIDs other than phenacetin leads to a pathologically or clinically defined renal disease that could be named AN or AAN.

C-reactive protein: the harbinger of cardiovascular diseases

Coronary heart disease remains the major cause of mortality and morbidity in the United States and other western countries despite major advances in its treatment. During the last decades, many markers of coronary artery disease have been found which help predict future risk of cardiovascular events. High-sensitivity C-reactive protein has been studied extensively and was seen to be associated with a higher risk of cardiovascular events in patients with acute coronary syndromes and/or peripheral artery disease. Discussed in this review is the latest literature about this marker and its association with cardiovascular disease, as well as the latest therapeutic options available.

Analgesic nephropathy and renal replacement therapy in Australia: trends, comorbidities and outcomes

BACKGROUND AND OBJECTIVES

This study examined age-specific incidence and prevalence of renal replacement therapy attributed to analgesic nephropathy from 1971 through 2005 and adjusted comorbidity prevalence and survival of patients who had analgesic nephropathy and were on renal replacement therapy (compared with control subjects without diabetes).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study, using data from the Australia and New Zealand Dialysis and Transplant registry, included all patients who were aged 35 to 84 yr and started long-term renal replacement therapy in Australia from 1971 through 2006.

RESULTS

Of 31,654 incident renal replacement therapy patients, 10.2% had analgesic nephropathy. Incidence and prevalence of renal replacement therapy attributed to analgesic nephropathy decreased earlier and faster among younger (age <55 yr) patients. Prevalence of analgesic nephropathy among 75- to 84-yr-old renal replacement therapy patients is still increasing. Compared with control subjects without diabetes, comorbidities (coronary artery, cerebrovascular, peripheral vascular, and chronic lung diseases) were more prevalent among patients with analgesic nephropathy at renal replacement therapy start. All-cause, cardiovascular, infection, and cancer mortality were higher among patients who had analgesic nephropathy and were on renal replacement therapy. For both comorbidities and mortality, the associations were stronger in younger patients.

CONCLUSIONS

Trends in renal replacement therapy attributed to analgesic nephropathy differed by age. Patients with analgesic nephropathy have more comorbidities and poorer survival on renal replacement therapy, especially among younger patients.

Prostaglandin E2 stimulates expression of osmoprotective genes in MDCK cells and promotes survival under hypertonic conditions

The cells of the renal medulla produce large amounts of prostaglandin E2 (PGE2) via cyclooxygenases (COX)-1 and -2. PGE2 is well known to play a critical role in salt and water balance and maintenance of medullary blood flow. Since renal medullary PGE2 production increases in antidiuresis, and since COX inhibition is associated with damage to the renal medulla during water deprivation, PGE2 may promote the adaptation of renal papillary cells to high interstitial solute concentrations. To address this question, MDCK cells were exposed to a gradual tonicity increase in the presence or absence of 20 microM PGE2 prior to analysis of (i) cell survival, (ii) expression of osmoprotective genes (AR, BGT1, SMIT, HSP70 and COX-2), (iii) subcellular TonEBP/NFAT5 abundance, (iv) TonEBP/NFAT5 transcriptional activity and (v) aldose reductase promoter activity. Cell survival and apoptotic indices after raising the medium tonicity improved markedly in the presence of PGE2. PGE2 significantly increased tonicity-mediated up-regulation of AR, SMIT and HSP70 mRNAs. However, neither nuclear abundance nor TonEBP/NFAT5-driven reporter activity were elevated by PGE2, but aldose reductase promoter activity was significantly increased by PGE2. Interestingly, tonicity-induced COX-2 expression and activity was also stimulated by PGE2, suggesting the existence of a positive feedback loop. These results demonstrate that the major medullary prostanoid, PGE2, stimulates the expression of osmoprotective genes and favours the adaptation of medullary cells to increasing interstitial tonicities, an effect that is not explained directly by the presence of TonEs in the promoter region of the respective target genes. These findings may be relevant in the pathophysiology of medullary damage associated with analgesic drugs.

Survival in Hostile Environments: Strategies of Renal Medullary Cells

Cells in the renal medulla exist in a hostile milieu characterized by wide variations in extracellular solute concentrations, low oxygen tensions, and abundant reactive oxygen species. This article reviews the strategies adopted by these cells to allow them to survive and fulfill their functions under these extreme conditions.

Drug Therapy in Dental Practice: Nonopioid and Opioid Analgesics

To prevent patient pain, the clinician may chose from opioid and nonopioid analgesics. It is rational for the practitioner to combine drugs from these classes when managing moderate to severe pain. To select combination regimens wisely, it is necessary to understand the significant pharmacological features of each category alone. Careful selection of an effective analgesic regimen based on the type and amount of pain the patient is expected to have can prevent the stress and anxiety associated with breakthrough pain. The clinician can and should develop a variety of effective, safe analgesic regimens, based on estimates of anticipated pain intensity that use sound pharmacological principles.

Nonsteroidal anti-inflammatory drugs and risk of ARF in the general population

BACKGROUND

Most epidemiological studies evaluating the association between nonsteroidal anti-inflammatory drugs (NSAIDs) and acute renal failure (ARF) found an increased risk for developing ARF while taking NSAIDs. Despite these studies, little is known about the effect of dose and duration of therapy, risk of individual NSAIDs, comorbidity, or concomitant use of other nephrotoxic drugs.

METHODS

This is a nested case-control study using the General Practice Research Database from the United Kingdom. Participants were 386,916 patients aged 50 to 84 years on January 1, 1997, and free of known cancer, renal disorder, cirrhosis, or systemic connective tissue disease. After validation of cases identified from this cohort, 103 patients were confirmed as idiopathic cases of ARF and compared with 5,000 controls frequency matched by age and sex.

RESULTS

Current users of NSAIDs had a relative risk (RR) for ARF of 3.2 (95% confidence interval [CI], 1.8 to 5.8), and the risk declined after treatment was discontinued. Increased risk was present with both short- and long-term therapy and was slightly greater among users of high doses. History of heart failure (HF), hypertension, diabetes, and hospitalizations and consultant visits in the previous year were all associated with a greater risk for ARF. There was a suggestion of a modification of the effect of NSAIDs in patients with hypertension and those with HF. Use of selected cardiovascular drugs was associated with a 5-fold increase in risk for ARF. Diuretics presented the greatest risk. Risk increased with concomitant use of NSAIDs and diuretics (RR, 11.6; 95% CI, 4.2 to 32.2) and NSAIDs and calcium channel blockers (RR, 7.8; 95% CI, 3.0 to 20.5).

CONCLUSION

NSAID users had a 3-fold greater risk for developing a first-ever diagnosis of clinical ARF compared with non-NSAID users in the general population. NSAIDs should be used with special caution in patients with hypertension and/or HF.

Renal Cyclooxygenase-2 (Cox-2)

BACKGROUND/AIMS

The role of COX-2 for renal function during renal development, for physiology and pathophysiology of renal diseases and the side effects of available COX-2 inhibitors, has gained increasing interest. We aimed therefore to review the respective role of renal COX-2.

METHODS

Review of relevant recent publications in the field, and in addition of in part unpublished data obtained in our laboratories.

RESULTS

COX-2 is 'constitutively' localized in the kidney i.e. in macula densa, TALH, interstitial cells, and is of utmost importance for normal renal development. Renal COX-2 is regulated by for example sodium and volume intake, angiotensin II, glucocorticoids often involving specific COX-2 promotor response elements. COX-2 derived prostanoids are required for preservation of renal blood flow and glomerular filtration especially in states of fluid deficit, they promote natriuresis, and furthermore may stimulate renin secretion during low-sodium intake/loop diuretic use. Conversely, COX-2 inhibitors decrease glomerular filtration, and renal perfusion, sometimes even causing acute renal failure. In addition, COX-2 inhibitors cause sodium retention, edema formation, cardiac failure and hypertension. The role of COX-2 derived prostanoids in renal inflammation or failure including diabetic nephropathy and renal transplantation remains at present controversial.

CONCLUSION

COX-2 is one of the major players in renal physiology and pathophysiology. One focus of future work should be placed on COX-2 in primary renal diseases.

Caffeine as a promoter of analgesic-associated nephropathy--where is the evidence?

Individual groups of nephrologists - in their responsibility for their patients - initiated a most controversial discussion whether or not caffeine - coformulated to analgesics - might initiate or sustain analgesic overdosing. The original sources (data) of such suspicion have got lost during the debate of the last two decades. Therefore, it seemed to be appropriate to investigate the original data background and the reasons why nephrologists started to suspect caffeine as a stimulant of analgesic overdosing by employing a systematic and exhaustive review of primary nephrological publications. Their selection followed a precise selection plan, including all epidemiological studies on analgesic-associated nephropathy, the original papers of all groups having been involved in those studies, further originals from the mainly involved countries (academically, politically), and any literature thereof cited as a proof. The following results emerged from the investigation: (i) The epidemiological studies warranted no conclusion about a role of caffeine in prompting excessive analgesic use. (ii) The identified groups of nephrologists provided not substantial data to advocate the said suspicion, except for the observation of a preferential choice of phenacetin-containing combinations, especially powder preparations. (iii) Only two cited original data sources revealed drug-seeking behaviour with phenacetin-containing preparations which subsided, after phenacetin was banned from the respective markets. Conclusively, it appears that there is no substantial data to support a pivotal role of caffeine in initiating or sustaining analgesic overdosing. However, there is strong data that phenacetin, by its psychotropic properties, may have caused drug-seeking behaviour and thus led to analgesic overdosing. This conclusion is convincingly supported by thorough pharmacokinetic investigations. Note: All caffeine-related statements within the reviewed literature have been collected in tables (referred to as Table SX) which are provided in full text for check on the following website: http://www.blackwellpublishing.com/products/journals/suppmat/FCP/FCP174/FCP174sm.htm

Aristolochic acid and 'Chinese herbs nephropathy': a review of the evidence to date

Chinese herbs nephropathy (CHN) is a rapidly progressive interstitial nephropathy reported after the introduction of Chinese herbs in a slimming regimen followed by young Belgian women. It is characterised by early, severe anaemia, mild tubular proteinuria and initially normal arterial blood pressure in half of the patients. Renal histology shows unusual extensive, virtually hypocellular cortical interstitial fibrosis associated with tubular atrophy and global sclerosis of glomeruli decreasing from the outer to the inner cortex. Urothelial malignancy of the upper urinary tract develops subsequently in almost half of the patients. Suspicion that the disease was due to the recent introduction of Chinese herbs in the slimming regimen was reinforced by identification in the slimming pills of the nephrotoxic and carcinogenic aristolochic acid (AA) extracted from species of Aristolochia. This hypothesis was substantiated by the identification of premutagenic AA-DNA adducts in the kidney and ureteric tissues of CHN patients. Finally, induction of the clinical features (interstitial fibrosis and upper urothelial malignancy) typical of CHN in rodents given AA alone removed any doubt on the causal role of this phytotoxin in CHN, now better called aristolochic acid nephropathy (AAN). AAN is not restricted to the Belgian cases. Similar cases have been observed throughout the world, but AA is sometimes incriminated on the basis of the known content of AA in the herbs. The possibility remains that in some individuals in whom AA has not been demonstrated, other phytotoxins might be implicated. Biological and morphological features of AAN are strikingly similar to those reported in another fibrosing interstitial nephropathy of still unknown aetiology, Balkan endemic nephropathy (BEN). Interestingly, AA was incriminated as the cause of BEN many years ago, a hypothesis yet to be fully explored. The intake of AA and the presence of tissular AA-DNA adducts in patients with an unequivocal diagnosis of BEN remains to be demonstrated. The tragic phenomenon of CHN, recognised only 10 years ago, has been at the root of significant research and progress both in nephrology and oncology. It has provided a fascinating opportunity to understand the link between a fibrosing interstitial nephropathy and urothelial carcinoma. It allows the categorisation of interstitial nephritis on the basis of histological findings, of initiating toxic substances and of associated clinical features. Finally, it has led to the withdrawal in several countries of a previously unsuspected carcinogenic and nephrotoxic substance.

18. Immune-mediated renal disease

Immune-mediated renal diseases can be classified by the clinical syndromes they produce, by the attendant renal pathology, or by the dominant immune effector mechanism of renal injury. The major clinical syndromes produced by immune-mediated renal injury include the nephrotic syndrome, the nephritic syndrome, rapidly progressive glomerulonephritis, and acute renal failure. The notion of clinical syndromes facilitates diagnosis and treatment, but does not accurately define disease pathogenesis. In this summary, we discuss pathologically defined immune-mediated renal diseases under the clinical syndrome with which they are most frequently associated. There is overlap between the clinical syndromes, but the syndromes provide a useful framework. Relevant information regarding the proposed pathogenesis of disease entities is included under specific disease entities.

The Renal Effects of Traditional Nonsteroidal Anti-Inflammatory Agents Versus Cyclooxygenase-2 Inhibitors

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for the management of acute and chronic pain as well as for rheumatoid arthritis and osteoarthritis. Although gastrointestinal complications are the most common adverse events associated with the use of these drugs, the renal adverse effects such as acute renal failure, electrolyte abnormalities, nephrotic syndrome, interstitial nephritis, and papillary necrosis can be serious. The cyclooxygenase-2 (COX-2)- selective NSAIDs (celecoxib, rofecoxib) have been associated with a reduced frequency of gastrointestinal adverse events, but questions still remain as to their renal safety. Recent information has suggested an increased role for COX-2 as a constitutive renal enzyme, thus implying its importance for normal kidney homeostasis. Clinical studies and published case reports of renal adverse events associated with COX-2 inhibitors suggest that patients with decreased effective circulating blood volume, salt depletion, and renal insufficiency have an increased likelihood of renal-related adverse events. Because many older patients have conditions that place them in one of the “at-risk” categories, this population should be monitored closely for the development of renal adverse events from any NSAIDs, including COX-2-selective agents.

Opposite effects of cyclooxygenase-1 and -2 activity on the pressor response to angiotensin II

Therapeutic use of cyclooxygenase-inhibiting (COX-inhibiting) nonsteroidal antiinflammatory drugs (NSAIDs) is often complicated by renal side effects including hypertension and edema. The present studies were undertaken to elucidate the roles of COX1 and COX2 in regulating blood pressure and renal function. COX2 inhibitors or gene knockout dramatically augment the pressor effect of angiotensin II (Ang II). Unexpectedly, after a brief increase, the pressor effect of Ang II was abolished by COX1 deficiency (either inhibitor or knockout). Ang II infusion also reduced medullary blood flow in COX2-deficient but not in control or COX1-deficient animals, suggesting synthesis of COX2-dependent vasodilators in the renal medulla. Consistent with this, Ang II failed to stimulate renal medullary prostaglandin E(2) and prostaglandin I(2) production in COX2-deficient animals. Ang II infusion normally promotes natriuresis and diuresis, but COX2 deficiency blocked this effect. Thus, COX1 and COX2 exert opposite effects on systemic blood pressure and renal function. COX2 inhibitors reduce renal medullary blood flow, decrease urine flow, and enhance the pressor effect of Ang II. In contrast, the pressor effect of Ang II is blunted by COX1 inhibition. These results suggest that, rather than having similar cardiovascular effects, the activities of COX1 and COX2 are functionally antagonistic.

Case report: the management of bone demineralization associated with long-term treatment of multiple paraphilias with long-acting LHRH agonists

A patient with multiple paraphilias had been successfully treated for 10 years with a long-acting LHRH agonist with complete suppression of deviant sexual activity. However, during treatment, he demonstrated bone demineralization, as documented by serial bone densitometry studies. A treatment regimen was instituted, which resulted in the cessation or partial reversal of bone loss.

A benefit-risk assessment of caffeine as an analgesic adjuvant

Caffeine has been an additive in analgesics for many years. However, the analgesic adjuvant effects of caffeine have not been seriously investigated since a pooled analysis conducted in 1984 showed that caffeine reduces the amount of paracetamol (acetaminophen) necessary for the same effect by approximately 40%. In vitro and in vivo pharmacological research has provided some evidence that caffeine can have anti-nociceptive actions through blockade of adenosine receptors, inhibition of cyclo-oxygenase-2 enzyme synthesis, or by changes in emotion state. Nevertheless, these actions are only considered in some cases. It is suggested that the actual doses of analgesics and caffeine used can influence the analgesic adjuvant effects of caffeine, and doses that are either too low or too high lead to no analgesic enhancement. Clinical trials suggest that caffeine in doses of more than 65 mg may be useful for enhancement of analgesia. However, except for in headache pain, the benefits are equivocal. While adding caffeine to analgesics increases the number of patients who become free from headache [rate ratio = 1.36, 95% confidence interval (CI) 1.17 to 1.58], it also leads to more patients with nervousness and dizziness (relative risk = 1.60, 95% CI 1.26 to 2.03). It is suggested that long-term use or overuse of analgesic medications is associated with rebound headache. However, there is no robust evidence that headache after use or withdrawal of caffeine-containing analgesics is more frequent than after other analgesics. Case-control studies have shown that caffeine-containing analgesics are associated with analgesic nephropathy (odds ratio = 4.9, 95% CI 2.3 to 10.3). However, no specific contribution of caffeine to analgesic nephropathy can be identified from these studies. Whether caffeine produces nephrotoxicity on its own, or increases nephrotoxicity due to analgesics, is yet to be established.

Renal and cardiovascular effects of selective cyclooxygenase-2 inhibitors

Selective inhibition of cyclooxygenase-2 (COX-2) was proposed as a novel anti-inflammatory and analgesic treatment with a reduced profile of gastrointestinal side effects compared with conventional nonsteroidal anti-inflammatory drugs (NSAIDs). Although perceived as an inducible enzyme by inflammatory and other stimuli, COX-2 is constitutively expressed in the kidney. In this review, we focus on renal and cardiovascular (CV) physiological and pathophysiological characteristics of COX-2 and renal and CV aspects of treatment with selective COX-2 inhibitors. Both clinical and experimental studies have shown that renal and CV effects of COX-2 inhibitors are similar to those of NSAIDs. These effects include sodium, potassium, and water retention and decreases in renal function, as well as mild to modest increases in blood pressure (BP) and edema. These deleterious effects are amplified in patients with volume and/or sodium depletion. The concomitant administration of COX-2 inhibitors may destabilize BP control in hypertensive patients treated with antihypertensive agents. In contrast to the normal kidney, which could constitute a target for adverse actions of COX-2 inhibitors, recent experimental studies showed increased renal COX-2 expression in several models of renal injury, such as the remnant kidney, renovascular hypertension, and diabetes, and implicated COX-2 in the progression of renal failure. This suggests that COX-2 inhibitors may confer a renoprotective effect in diverse renal disorders. These intriguing formulations must be delineated further in appropriately designed prospective clinical trials.