A nationwide nested case-control study indicates an increased risk of acute interstitial nephritis with proton pump inhibitor use

Emerging dilemmas in the diagnosis and management of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is common, but less so than widely reported because of inconsistencies in definition. In clinical practice, the diagnosis is usually based on a symptom assessment without testing, and the extent of diagnostic testing pursued should be limited to that which guides management or which protects the patient from the risks of a potentially morbid treatment or an undetected early (or imminent) esophageal adenocarcinoma or which does both. When testing is pursued, upper gastrointestinal endoscopy is the most useful initial diagnostic test because it evaluates for the major potential morbidities (Barrett's, stricture, and cancer) associated with GERD and facilitates the identification of some alternative diagnostic possibilities such as eosinophilic esophagitis. However, endoscopy is insensitive for diagnosing GERD because most patients with GERD have non-erosive reflux disease, a persistent diagnostic dilemma. Although many studies have tried to objectify the diagnosis of GERD with improved technology, this is ultimately a pragmatic diagnosis based on response to proton pump inhibitor (PPI) therapy, and, in the end, response to PPI therapy becomes the major indication for continued PPI therapy. Conversely, in the absence of objective criteria for GERD and the absence of apparent clinical benefit, PPI therapy is not indicated and should be discontinued. PPIs are well tolerated and safe, but nothing is perfectly safe, and in the absence of measurable benefit, even a miniscule risk dominates the risk-benefit assessment.

Proton Pump Inhibitors in Gastroesophageal Reflux Disease: Friend or Foe

PURPOSE OF REVIEW

Proton pump inhibitor (PPI) use in gastroesophageal reflux disease (GERD) has been redefined, in light of recent advances highlighting GERD phenotypes that respond to PPIs, and fresh revelations of potential risks of long-term PPI therapy.

RECENT FINDINGS

Erosive esophagitis predicts excellent response to PPI therapy, but non-erosive reflux disease (NERD) with abnormal reflux parameters on ambulatory reflux monitoring also demonstrates a similar response. In contrast, response is suboptimal in the absence of abnormal reflux parameters. In this setting, if an alternate appropriate indication for PPI therapy does not coexist, risks may outweigh benefits of PPI therapy. Adverse events from long-term PPI therapy continue to be reported, most based on association rather than cause-and-effect. Appropriate indications need to be established before embarking on long-term PPI therapy. Future research will define true risks of long-term PPI therapy, and develop alternate management options for acid peptic diseases.

Association Between Proton Pump Inhibitor Use and Risk of Progression of Chronic Kidney Disease

BACKGROUND & AIMS

Proton pump inhibitors (PPI) have been associated with acute kidney injury and recent studies suggest that they may be associated with the risk of chronic kidney disease (CKD).

METHODS

We performed a retrospective analysis using the Stockholm creatinine measurements database, which contains information on diagnoses, dispensation claims, and laboratory test results for all citizens in the Stockholm region from 2007 through 2010. We identified new users of PPIs (n = 105,305) and new users of H₂ blockers (H₂B; n = 9578); data on renal outcomes were collected for a median 2.7 years. The primary outcome was progression CKD, defined as doubling of creatinine or decrease in estimated glomerular filtration rate of 30% or more. Secondary outcomes were end-stage renal disease and acute kidney injury. Complete collection of repeated PPI and H₂B dispensations at pharmacies in Sweden allowed modeling the time-dependent risk associated with cumulative PPI exposure.

RESULTS

Users of PPIs, compared with users of H₂Bs, had an increased risk for doubled levels of creatinine (1985 events; adjusted hazard ratio [HR], 1.26; 95% CI, 1.05-1.51) and decrease in estimated glomerular filtration rate of 30% or more (11,045 events; 1.26; 95% CI, 1.16-1.36). PPI use also associated with development of end-stage renal disease (HR, 2.40; 95% CI, 0.76-7.58) and acute kidney injury (HR, 1.30; 95% CI, 1.00-1.69). There was a graded association between cumulative exposure to PPIs and risk of CKD progression. This was not the case for cumulative H₂B use.

CONCLUSIONS

Initiation of PPI therapy and cumulative PPI exposure is associate with increased risk of CKD progression in a large, North European healthcare system. Although consistent, the association was modest in magnitude, and cannot exclude residual confounding.

Adverse effects of proton-pump inhibitor use in older adults: a review of the evidence

Proton-pump inhibitors (PPIs) are a widely prescribed class of medications used to treat acid-related disorders and use has significantly increased over the last few decades. PPIs are often inappropriately prescribed and since they have been on the market, a number of post-marketing studies have been published demonstrating associations between longer duration of PPI therapy and a number of adverse effects that are a concern in older adults. The objective of this review is to discuss the existing literature of potential adverse effects with long-term PPI use in older adults and to summarize the implications in clinical practice. A PubMed search was conducted to identify studies evaluating the potential long-term adverse effects of PPI therapy in older adults, and publications were selected based on relevant criteria. PPIs have been associated with an increased risk of a number of adverse effects including osteoporotic-related fractures, Clostridium difficile infection, community-acquired pneumonia, vitamin B12 deficiency, kidney disease, and dementia, demonstrated by a number of case-control, cohort studies, and meta-analyses. Older adults should be periodically evaluated for the need for continued use of PPI therapy given the number of potential adverse effects associated with long-term use.

Simvastatin dose and acute kidney injury without concurrent serious muscle injury: A nationwide nested case-control study

Background

Inconsistent findings from four observational studies suggest that the risk of acute kidney injury (AKI) may increase with increasing statin dose or potency, but none of the studies took statin-related severe muscle injury, including rhabdomyolysis, into account. We undertook a nationwide nested case-control study in New Zealand to examine the risk of AKI without concurrent serious muscle injury according to simvastatin dose in two cohorts: people without a history of renal disease and people with non-dialysis dependent chronic kidney disease.

Materials and methods

A total of 334,710 people aged ≥ 18 years without a history of renal disease (cohort 1) and 5,437 with non-dialysis dependent chronic kidney disease (cohort 2) who initiated simvastatin therapy between 1 January 2006 and 31 December 2013 were identified using national pharmaceutical dispensing and hospital discharge data. Patients who developed AKI without concurrent serious muscle injury during follow-up (cases) were ascertained using hospital discharge and mortality data (n = 931 from cohort 1, n = 160 from cohort 2). Up to 10 controls per case, matched by date of birth, sex, and cohort entry date were randomly selected from the relevant cohort using risk set sampling.

Results

Relative to current use of 20mg simvastatin daily, the adjusted odds ratios and 95% confidence intervals (95% CI) in cohort 1 for current use of 40mg and 80mg were 0.9 (95% CI 0.7–1.2) and 1.3 (95% CI 0.7–2.3), respectively. The adjusted odds ratio for 40mg in cohort 2 was 1.1 (95% CI 0.7–1.9); the numbers taking 80mg were very small and the confidence interval was correspondingly wide.

Conclusion

The findings of this study suggest that a relationship between statin dose and AKI may not exist independent of serious muscle injury.

Risk of death among users of Proton Pump Inhibitors: a longitudinal observational cohort study of United States veterans

OBJECTIVE

Proton pump inhibitors (PPIs) are widely used, and their use is associated with increased risk of adverse events. However, whether PPI use is associated with excess risk of death is unknown. We aimed to examine the association between PPI use and risk of all-cause mortality.

DESIGN

Longitudinal observational cohort study.

SETTING

US Department of Veterans Affairs.

PARTICIPANTS

Primary cohort of new users of PPI or histamine H2 receptor antagonists (H2 blockers) (n=349 312); additional cohorts included PPI versus no PPI (n=3 288 092) and PPI versus no PPI and no H2 blockers (n=2 887 030).

MAIN OUTCOME MEASURES

Risk of death.

RESULTS

Over a median follow-up of 5.71 years (IQR 5.11-6.37), PPI use was associated with increased risk of death compared with H2 blockers use (HR 1.25, CI 1.23 to 1.28). Risk of death associated with PPI use was higher in analyses adjusted for high-dimensional propensity score (HR 1.16, CI 1.13 to 1.18), in two-stage residual inclusion estimation (HR 1.21, CI 1.16 to 1.26) and in 1:1 time-dependent propensity score-matched cohort (HR 1.34, CI 1.29 to 1.39). The risk of death was increased when considering PPI use versus no PPI (HR 1.15, CI 1.14 to 1.15), and PPI use versus no PPI and no H2 blockers (HR 1.23, CI 1.22 to 1.24). Risk of death associated with PPI use was increased among participants without gastrointestinal conditions: PPI versus H2 blockers (HR 1.24, CI 1.21 to 1.27), PPI use versus no PPI (HR 1.19, CI 1.18 to 1.20) and PPI use versus no PPI and no H2 blockers (HR 1.22, CI 1.21 to 1.23). Among new PPI users, there was a graded association between the duration of exposure and the risk of death.

CONCLUSIONS

The results suggest excess risk of death among PPI users; risk is also increased among those without gastrointestinal conditions and with prolonged duration of use. Limiting PPI use and duration to instances where it is medically indicated may be warranted.

Complications of Proton Pump Inhibitor Therapy

Safety issues associated with proton pump inhibitors (PPIs) have recently attracted widespread media and lay attention. Gastroenterologists are frequently asked about the appropriateness of PPI therapy for specific patients. Furthermore, some patients may have had PPI therapy discontinued abruptly or inappropriately due to safety concerns. Faced with such a wide variety of potentially serious adverse consequences, prescribers need to evaluate the evidence objectively to discern the likelihood that any reported association might actually be causal. Here, we review many of the proposed adverse consequences of PPI therapy and apply established criteria for the determination of causation. We also consider the potential contribution of residual confounding in many of the reported studies. Evidence is inadequate to establish causal relationships between PPI therapy and many of the proposed associations. Residual confounding related to study design and the overextrapolation of quantitatively small estimates of effect size have probably led to much of the current controversy about PPI safety. In turn, this has caused unnecessary concern among patients and prescribers. The benefits of PPI therapy for appropriate indications need to be considered, along with the likelihood of the proposed risks. Patients with a proven indication for a PPI should continue to receive it in the lowest effective dose. PPI dose escalation and continued chronic therapy in those unresponsive to initial empiric therapy is discouraged.

Proton pump inhibitors: Risks of long-term use

Proton pump inhibitors are among the most commonly prescribed classes of drugs, and their use is increasing, in particular for long-term treatment, often being over-prescribed and used for inappropriate conditions. In recent years, considerable attention has been directed towards a wide range of adverse effects, and even when a potential underlying biological mechanism is plausible, the clinical evidence of the adverse effect is often weak. Several long-term side effects have been investigated ranging from interaction with other drugs, increased risk of infection, reduced intestinal absorption of vitamins and minerals, and more recently kidney damage and dementia. The most recent literature regarding these adverse effects and their association with long-term proton pump inhibitor treatment is reviewed, and the mechanisms through which these possible complications might develop are discussed.

A Retrospective Study to Assess the Effect of Proton Pump Inhibitors on Renal Profile in a South Indian Hospital

INTRODUCTION

Proton Pump Inhibitors (PPIs) are arguably among the most commonly prescribed drugs in clinical practice, either as part of treatment or prophylaxis. Many clinicians prescribe these drugs as part of any prescription, without a proper rationale. Recent studies done outside India have shown that these drugs are not entirely safe, and they can result in the development of acute renal injury.

AIM

To assess the effect of PPIs on blood urea and serum creatinine, when administered for at least seven consecutive days.

MATERIALS AND METHODS

The study was conducted in a retrospective manner, using data from the medical records department. Values of blood urea and serum creatinine were taken twice, first before start of therapy and then after at least one week of therapy.

RESULTS

A total of 175 subjects were selected for the study. When their case files were analysed, acute kidney injury was identified in 19 (10.86%) of them. Pantoprazole was the most common drug involved (84.21%). Renal injury was more common in the age group of over 50 years of age.

CONCLUSION

PPIs are not entirely free of adverse effects, as assumed by several practitioners. A vigilant eye has to be maintained on the patient's renal profile so as to avoid any untoward decline in renal function, as evidenced in the current study.

The Safety of Appropriate Use of Over-the-Counter Proton Pump Inhibitors: An Evidence-Based Review and Delphi Consensus

The availability of over-the-counter (OTC) proton pump inhibitors (PPIs) for the short-term (2 weeks) management of frequent heartburn (≥2 days/week) has increased markedly, yet evidence-based recommendations have not been developed. A panel of nine international experts in gastroesophageal reflux disease developed consensus statements regarding the risks and benefits of OTC PPIs using a modified Delphi process. Consensus (based on ≥80% approval) was reached through multiple rounds of remote voting and a final round of live voting. To identify relevant data, the available literature was searched and summarized. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system terminology was used to rate the quality of evidence and strength of recommendations; consensus was based on ≥2/3 agreement. After 4 rounds of review, consensus was achieved for 18 statements. Notably, the available data did not directly reflect OTC use, but instead, prescription use; therefore, extrapolations to the OTC setting were often necessary. This limitation is regrettable, but it justifies performing this exercise to provide evidence-based expert opinion on a widely used class of drugs. The panel determined that using OTC PPIs according to label instructions is unlikely to mask the symptoms of esophageal or gastric cancer or adversely impact the natural history of related precursor conditions. OTC PPIs are not expected to substantially affect micronutrient absorption or bone mineral density or cause community-acquired pneumonia, Clostridium difficile infection, or cardiovascular adverse events. However, OTC PPI use may be associated with slightly increased risks for infectious diarrhea, certain idiosyncratic reactions, and cirrhosis-related spontaneous bacterial peritonitis. The available evidence does not suggest that OTC PPI use consistent with label instructions is associated with substantial health risks. To minimize potential risks, healthcare professionals and consumers must actively participate in decision making when managing reflux-related symptoms in the self-care setting.

A Review of the Novel Application and Potential Adverse Effects of Proton Pump Inhibitors

Proton pump inhibitors (PPIs) are known as a class of pharmaceutical agents that target H⁺/K⁺-ATPase, which is located in gastric parietal cells. PPIs are widely used in the treatment of gastric acid-related diseases including peptic ulcer disease, erosive esophagitis and gastroesophageal reflux disease, and so on. These drugs present an excellent safety profile and have become one of the most commonly prescribed drugs in primary and specialty care. Except for gastric acid-related diseases, PPIs can also be used in the treatment of Helicobacter pylori infection, viral infections, respiratory system diseases, cancer and so on. Although PPIs are mainly used short term in patients with peptic ulcer disease, nowadays these drugs are increasingly used long term, and frequently for a lifetime, for instance in patients with typical or atypical symptoms of gastroesophageal reflux disease and in NSAID or aspirin users at risk of gastrotoxicity and related complications including hemorrhage, perforation and gastric outlet obstruction. Long-term use of PPIs may lead to potential adverse effects, such as osteoporotic fracture, renal damage, infection (pneumonia and clostridium difficile infection), rhabdomyolysis, nutritional deficiencies (vitamin B12, magnesium and iron), anemia and thrombocytopenia. In this article, we will review some novel uses of PPIs in other fields and summarize the underlying adverse reactions.

Acute interstitial nephritis in the south of Iran; an observational study

Background

Acute interstitial nephritis (AIN) is an emerging cause of acute kidney injury (AKI) during the recent years.

Objectives:

There is no data about prevalence, causes, clinical manifestation and outcomes of AIN in our region. Hence, in this study we aimed to find the prevalence of AIN and describe the causes, clinical presentation, and the outcome of AIN in the native kidney biopsies.

Patients and Methods:

We reviewed 934 native kidney biopsies from 2006 to 2014 and collected the data of patients with the diagnosis of AIN including medical history, clinical findings, para-clinical data, pathologic findings, treatment and outcomes.

Results:

Prevalence of AIN in our center during 2006 to 2014 was 2.5% of all renal biopsies. The common cause of AIN in our study was drugs. Of those patients admitted to hospital due to AIN, 17 patients (70.8%) received corticosteroid, five of them (29.4%) received pulse of corticosteroid, and 12 patients (70.6%) received oral drug. Around, 54.2% of the patients had hemodialysis during admission. Eight patients had received both dialysis and corticosteroid. Two of them (8.3%) remained on dialysis and 8 (33.3%) developed chronic kidney disease, but 14 (58.3%) patients recovered.

Conclusions:

The prevalence of AIN in our study is comparable to other studies and we found the great impact of medications on development of AIN.

The 6R's of drug induced nephrotoxicity

Drug induced kidney injury is a frequent adverse event which contributes to morbidity and increased healthcare utilization. Our current knowledge of drug induced kidney disease is limited due to varying definitions of kidney injury, incomplete assessment of concurrent risk factors and lack of long term outcome reporting. Electronic surveillance presents a powerful tool to identify susceptible populations, improve recognition of events and provide decision support on preventative strategies or early intervention in the case of injury. Research in the area of biomarkers for detecting kidney injury and genetic predisposition for this adverse event will enhance detection of injury, identify those susceptible to injury and likely mitigate risk. In this review we will present a 6R framework to identify and mange drug induced kidney injury – risk, recognition, response, renal support, rehabilitation and research.

Medication-Induced Interstitial Nephritis in the 21st Century

Interstitial nephritis is an immune mediated form of tubulointerstitial kidney injury that may occur secondary to drugs, autoimmune disease, infections, and hematologic disorders or as a reactive process. Drug-induced acute interstitial nephritis (DI-AIN) occurs in 0.5%-3% of all kidney biopsies and in 5%-27% of biopsies performed for acute kidney injury. Drugs are implicated in 70%-90% of biopsy-proved IN with a prevalence of 50% in less developed to 78% in more developed countries. DI-AIN typically is idiosyncratic because of a delayed hypersensitivity reaction, although some chemotherapeutic agents are permissive for immune upregulation and injure the kidney in a dose-related manner. Antibiotics are the most implicated class of medication in DI-AIN, followed by proton pump inhibitors, nonsteroidal anti-inflammatory agents, and 5-aminosalicylates. Diuretics, allopurinol, phenytoin and other anti-seizure medications, and H2 receptor antagonists are known offenders while chemotherapeutic agents are an under-recognized cause. The symptoms of DI-AIN are variable and often not specific; thus, kidney biopsy is required to make a firm diagnosis. The incidence of DI-AIN appears to be increasing, particularly in the elderly in whom kidney biopsy is underused, and identification of the offending agent may be complicated by polypharmacy. As rapid drug discontinuation may improve prognosis, the possibility of DI-AIN should always be considered in a patient with acute kidney injury.

Long-term kidney outcomes among users of proton pump inhibitors without intervening acute kidney injury

Proton pump inhibitor (PPI) use is associated with an increased risk of acute kidney injury (AKI), incident chronic kidney disease (CKD), and progression to end-stage renal disease (ESRD). PPI-associated CKD is presumed to be mediated by intervening AKI. However, whether PPI use is associated with an increased risk of chronic renal outcomes in the absence of intervening AKI is unknown. To evaluate this we used the Department of Veterans Affairs national databases to build a cohort of 144,032 incident users of acid suppression therapy that included 125,596 PPI and 18,436 Histamine H2 receptor antagonist (H2 blockers) consumers. Over 5 years of follow-up in survival models, cohort participants were censored at the time of AKI occurrence. Compared with incident users of H2 blockers, incident users of PPIs had an increased risk of an estimated glomerular filtration rate (eGFR) under 60 ml/min/1.73m² (hazard ratio 1.19; 95% confidence interval 1.15-1.24), incident CKD (1.26; 1.20-1.33), eGFR decline over 30% (1.22; 1.16-1.28), and ESRD or eGFR decline over 50% (1.30; 1.15-1.48). Results were consistent in models that excluded participants with AKI either before chronic renal outcomes, during the time in the cohort, or before cohort entry. The proportion of PPI effect mediated by AKI was 44.7%, 45.47%, 46.00%, and 46.72% for incident eGFR under 60 ml/min/1.73m², incident CKD, eGFR decline over 30%, and ESRD or over 50% decline in eGFR, respectively. Thus, PPI use is associated with increased risk of chronic renal outcomes in the absence of intervening AKI. Hence, reliance on antecedent AKI as warning sign to guard against the risk of CKD among PPI users is not sufficient as a sole mitigation strategy.

Review of the Long-Term Effects of Proton Pump Inhibitors

Proton pump inhibitors are widely used, but up to 70% of patients take them without an appropriate indication and face risk of adverse effects associated with long-term use.

Demographic and regional disparities in insulin pump utilization in a setting of universal funding: a New Zealand nationwide study

AIMS

Insulin pumps have been publically funded in New Zealand since 2012 for patients who meet certain clinical criteria; however, the patterns of utilization have not been described. We undertook a nationwide study to estimate the annual proportions of patients with type 1 diabetes mellitus who used a pump between 2012 and 2014, overall, and according to sex, age, ethnicity, socioeconomic position, and region.

METHODS

We used data from the New Zealand Virtual Diabetes Register and routinely collected national demographic, health, and pharmaceutical dispensing data from the Ministry of Health to identify patients with type 1 diabetes and to calculate the overall, and subgroup, proportions using pumps.

RESULTS

Between 2012 and 2014, funded pump use among patients with type 1 diabetes (n = 13,727) increased from 1.8 to 9.3 % overall; however, there were differences in uptake according to demographic characteristics and region. In 2014, proportionate pump use was significantly higher in females versus males (adjusted odds ratio (OR) 2.0 [95 % confidence interval 1.8-2.3]), in those aged <20 years, and in some regions. Māori (indigenous people), Pacific, and Asian patients were significantly less likely to use pumps than New Zealand Europeans (ORs 0.30 [0.23-0.41], 0.26 [0.14-0.46], 0.22 [0.14-0.35], respectively), as were those in the most versus the least deprived socioeconomic decile (OR 0.36 [0.25-0.52]).

CONCLUSIONS

It is essential to explore the factors driving differential insulin pump uptake, in both New Zealand and elsewhere, if all patients are to have equal opportunity to benefit from intensive diabetes management.

Role of Oxidative Stress in Drug-Induced Kidney Injury

The kidney plays a primary role in maintaining homeostasis and detoxification of numerous hydrophilic xenobiotics as well as endogenous compounds. Because the kidney is exposed to a larger proportion and higher concentration of drugs and toxins than other organs through the secretion of ionic drugs by tubular organic ion transporters across the luminal membranes of renal tubular epithelial cells, and through the reabsorption of filtered toxins into the lumen of the tubule, these cells are at greater risk for injury. In fact, drug-induced kidney injury is a serious problem in clinical practice and accounts for roughly 20% of cases of acute kidney injury (AKI) among hospitalized patients. Therefore, its early detection is becoming more important. Usually, drug-induced AKI consists of two patterns of renal injury: acute tubular necrosis (ATN) and acute interstitial nephritis (AIN). Whereas AIN develops from medications that incite an allergic reaction, ATN develops from direct toxicity on tubular epithelial cells. Among several cellular mechanisms underlying ATN, oxidative stress plays an important role in progression to ATN by activation of inflammatory response via proinflammatory cytokine release and inflammatory cell accumulation in tissues. This review provides an overview of drugs associated with AKI, the role of oxidative stress in drug-induced AKI, and a biomarker for drug-induced AKI focusing on oxidative stress.

Proton Pump Inhibitors Are Not Associated With Acute Kidney Injury in Critical Illness

Recent epidemiologic data linking proton pump inhibitor (PPI) use to acute and chronic kidney dysfunction is yet to be validated in other populations, and mechanisms have not been explored. Using a large, well phenotyped inception cohort of 15 063 critically ill patients, we examined the risk of acute kidney injury (AKI), as defined by the Kidney Disease Improving Global Outcomes criteria guidelines, according to prior use of a PPI, histamine-2 receptor antagonist (H₂ RA), or neither. A total of 3725 (24.7%) patients reported PPI use prior to admission, while 905 (6.0%) patients reported H₂ RA use. AKI occurred in 747 (20.0%) and 163 (18.0%) of PPI and H₂ RA users respectively, compared to 1712 (16.2%) of those not taking acid suppressive medications. In unadjusted analysis, PPI and H₂ RA users had a 28% (95%CI 1.17-1.41, P < .001) and 10% (95%CI 0.91-1.30, P = .31) higher risk of AKI compared to those taking neither class of medication. However, in sequential models that included adjustment for demographics, cardiovascular comorbidities, indications for PPI use, and severity of illness, the effect of PPI on the risk of AKI was attenuated, and in the adjusted analysis, PPI was not associated with AKI (OR 1.02; 95%CI 0.91-1.13, P = .73). The presence of sterile pyuria and hypomagnesemia did not modify the association between PPI use and AKI. In summary, after adjustment for demographics, illness severity, and the indication for PPI use, PPI use prior to admission is not associated with critical illness AKI.

Adult and paediatric GERD: diagnosis, phenotypes and avoidance of excess treatments

Detailed investigations and objective measurements in patients with symptoms of gastro-oesophageal reflux should be performed with the intent of making the correct diagnosis, thus enabling choice of appropriate therapy. Establishing the most effective therapy is particularly important in adults who do not respond to standard treatment and in children. The use of PPIs for suspected GERD has increased substantially over the past decade, providing great relief in patients with acid-related symptoms, but also leading to adverse effects and a considerable economic burden. Adults with functional heartburn do not benefit from PPIs, while prolonged PPI use in patients with extraoesophageal symptoms remains a controversial area. Moreover, PPIs are not indicated in infants with GERD unless symptoms are proven to be acid-related. With regard to antireflux surgery, patients must be carefully selected to avoid the need for ongoing PPI treatment postoperatively. Correct diagnosis and phenotyping of patients with symptoms attributed to gastro-oesophageal reflux through detailed investigations is therefore imperative, leading to improved patient outcomes and rationalized use of available treatment options. In this Review, we outline currently available diagnostic tests and discuss approaches to limit any unnecessary medical or surgical interventions.

Adverse reactions and rational use of proton pump inhibitors

Proton pump inhibitors (PPIs) are a class of important drugs for treating acid related diseases, such as gastroesophageal reflux diseases (GERD), peptic ulcer, Zollinger-Ellison syndrome, and upper gastrointestinal bleeding. When combined with other drugs, PPIs can be used for the eradication of Helicobacter pylori. Short-term use of PPIs can cause allergic reactions, adverse reactions of the hematologic system, the digestive system and the nervous system and so on. Long-term use of PPIs can cause a series of new safety issues, such as increased risk of infection, vitamin B₁₂ deficiency caused by the lack of nutrients, fractures, hypomagnesemia, occurrence or development of atrophic gastritis, interstitial nephritis, microscopic colitis, increased risk of serious skin allergy and so on. However, inappropriate use and off-label use of PPIs, and even abuse of PPIs are very common worldwide. Therefore, clinical rational use of PPIs should be emphasized among the relevant national administration departments, clinicians and pharmacists.

Proton pump inhibitors are associated with increased risk of development of chronic kidney disease

Background

Acute interstitial nephritis secondary to proton pump inhibitors (PPIs) frequently goes undiagnosed due to its subacute clinical presentation, which may later present as chronic kidney disease (CKD). We investigated the association of PPI use with the development of CKD and death.

Methods

Two separate retrospective case–control study designs were employed with a prospective logistic regression analysis of data to evaluate the association of development of CKD and death with PPI use. The population included 99,269 patients who were seen in primary care VISN2 clinics from 4/2001 until 4/2008. For evaluation of the CKD outcome, 22,807 with preexisting CKD at the first observation in Veterans Affairs Health Care Upstate New York (VISN2) network data system were excluded. Data obtained included use of PPI (Yes/No), demographics, laboratory data, pre-PPI comorbidity variables.

Results

A total of 19,311/76,462 patients developed CKD. Of those who developed CKD 24.4 % were on PPI. Patients receiving PPI were less likely to have vascular disease, COPD, cancer and diabetes. Of the total of 99,269 patients analyzed for mortality outcome, 11,758 died. A prospective logistic analysis of case–control data showed higher odds for development of CKD (OR 1.10 95 % CI 1.05–1.16) and mortality (OR 1.76, 95 % CI 1.67–1.84) among patients taking PPIs versus those not on PPIs.

Conclusions

Use of proton pump inhibitors is associated with increased risk of development of CKD and death. With the large number of patients being treated with proton pump inhibitors, healthcare providers need to be better educated about the potential side effects of these medications.

Proton Pump Inhibitors and Risk of Incident CKD and Progression to ESRD

The association between proton pump inhibitors (PPI) use and risk of acute interstitial nephritis has been described. However, whether exposure to PPI associates with incident CKD, CKD progression, or ESRD is not known. We used Department of Veterans Affairs national databases to build a primary cohort of new users of PPI (n=173,321) and new users of histamine H₂-receptor antagonists (H₂ blockers; n=20,270) and followed these patients over 5 years to ascertain renal outcomes. In adjusted Cox survival models, the PPI group, compared with the H₂ blockers group, had an increased risk of incident eGFR<60 ml/min per 1.73 m² and of incident CKD (hazard ratio [HR], 1.22; 95% confidence interval [95% CI], 1.18 to 1.26; and HR, 1.28; 95% CI, 1.23 to 1.34, respectively). Patients treated with PPI also had a significantly elevated risk of doubling of serum creatinine level (HR, 1.53; 95% CI, 1.42 to 1.65), of eGFR decline >30% (HR, 1.32; 95% CI, 1.28 to 1.37), and of ESRD (HR, 1.96; 95% CI, 1.21 to 3.18). Furthermore, we detected a graded association between duration of PPI exposure and risk of renal outcomes among those exposed to PPI for 31-90, 91-180, 181-360, and 361-720 days compared with those exposed for ≤30 days. Examination of risk of renal outcomes in 1:1 propensity score-matched cohorts of patients taking H₂ blockers versus patients taking PPI and patients taking PPI versus controls yielded consistent results. Our results suggest that PPI exposure associates with increased risk of incident CKD, CKD progression, and ESRD.

Association of proton pump inhibitors with the occurrence of gut-derived bacteraemia in patients with haematological malignancy after chemotherapy

BACKGROUND

Gut-derived bacteraemia is a major complication in patients with haematological malignancy after chemotherapy.

OBJECTIVE

Our study aimed to investigate the role of proton pump inhibitors (PPIs) in the occurrence of gut-derived bacteraemia.

METHODS

We compared data from 92 hospitalized haematological malignancy patients after chemotherapy with gut-derived bacteraemia, collected from January 2009 to July 2015, with those of 92 contemporaneous, hospitalized haematological malignancy patients without bacteraemia. We evaluated PPIs use and analysed the effects of covariates.

RESULTS

Patients with gut-derived bacteraemia had a significantly higher incidence of PPIs use (69.6%) than that of controls (47.8%). Of the patients with gut-derived bacteraemia, only 44.6% had a documented indication for PPIs therapy. The antibacterial prophylaxis rate was 38.0% in the bacteraemia group and 58.7% in the non-antibacterial group. Based on multivariable logistic regression analysis, only PPIs use (P = 0.00, odds ratio (OR) = 0.546) was found to be associated with the risk of bacteraemia whereas antibacterial prophylaxis (P = 0.00, OR = 0.652) was protective. There were no significant differences in demographics, malignancy status, length of neutropenia, complications, or steroid use between the gut-derived bacteraemia and control group.

CONCLUSIONS

This study suggests a potential association between PPIs use and development of gut-derived bacteraemia in haematological malignancy patients after chemotherapy.

[Interstitial nephritis in rheumatic diseases]

Interstitial nephritis is responsible for about 12 % of end-stage renal disease in Germany. It comprises an etiologically heterogenous group of inflammatory renal disorders which primarily affect the renal interstitium and tubuli. Drugs, predominantly antibiotics, nonsteroidal anti-inflammatory drugs and proton pump inhibitors are causative in the majority of cases. Rheumatic diseases frequently affect the kidneys, either the glomeruli or the interstitial tissues. Inflammatory interstitial processes can be accompanied by complex functional tubular disorders. This review gives an overview about clinical and laboratory findings of interstitial nephritis in the context of rheumatic diseases. Sarcoidosis, tubulointerstitial nephritis and uveitis (TINU) syndrome, primary Sjogren's syndrome, and IgG4-related disease often show an interstitial nephritis when the kidneys are affected. Other diseases, such as systemic lupus erythematosus, systemic sclerosis, drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome, and granulomatosis with polyangiitis are more rarely associated with predominant interstitial nephritis. Glucocorticoids are the mainstay of therapy for most cases; in refractory cases or when side effects occur, second-line immunosuppressants such as mycophenolate mofetil, azathioprine and others, rarely biologics, can be used.

Proton Pump Inhibitor Use and the Risk of Chronic Kidney Disease

IMPORTANCE

Proton pump inhibitors (PPIs) are among the most commonly used drugs worldwide and have been linked to acute interstitial nephritis. Less is known about the association between PPI use and chronic kidney disease (CKD).

OBJECTIVE

To quantify the association between PPI use and incident CKD in a population-based cohort.

DESIGN, SETTING, AND PARTICIPANTS

In total, 10,482 participants in the Atherosclerosis Risk in Communities study with an estimated glomerular filtration rate of at least 60 mL/min/1.73 m(2) were followed from a baseline visit between February 1, 1996, and January 30, 1999, to December 31, 2011. The data was analyzed from May 2015 to October 2015. The findings were replicated in an administrative cohort of 248,751 patients with an estimated glomerular filtration rate of at least 60 mL/min/1.73 m(2) from the Geisinger Health System.

EXPOSURES

Self-reported PPI use in the Atherosclerosis Risk in Communities study or an outpatient PPI prescription in the Geisinger Health System replication cohort. Histamine2 (H2) receptor antagonist use was considered a negative control and active comparator.

MAIN OUTCOMES AND MEASURES

Incident CKD was defined using diagnostic codes at hospital discharge or death in the Atherosclerosis Risk in Communities Study, and by a sustained outpatient estimated glomerular filtration rate of less than 60 mL/min/1.73 m(2) in the Geisinger Health System replication cohort.

RESULTS

Among 10,482 participants in the Atherosclerosis Risk in Communities study, the mean (SD) age was 63.0 (5.6) years, and 43.9% were male. Compared with nonusers, PPI users were more often of white race, obese, and taking antihypertensive medication. Proton pump inhibitor use was associated with incident CKD in unadjusted analysis (hazard ratio [HR], 1.45; 95% CI, 1.11-1.90); in analysis adjusted for demographic, socioeconomic, and clinical variables (HR, 1.50; 95% CI, 1.14-1.96); and in analysis with PPI ever use modeled as a time-varying variable (adjusted HR, 1.35; 95% CI, 1.17-1.55). The association persisted when baseline PPI users were compared directly with H2 receptor antagonist users (adjusted HR, 1.39; 95% CI, 1.01-1.91) and with propensity score-matched nonusers (HR, 1.76; 95% CI, 1.13-2.74). In the Geisinger Health System replication cohort, PPI use was associated with CKD in all analyses, including a time-varying new-user design (adjusted HR, 1.24; 95% CI, 1.20-1.28). Twice-daily PPI dosing (adjusted HR, 1.46; 95% CI, 1.28-1.67) was associated with a higher risk than once-daily dosing (adjusted HR, 1.15; 95% CI, 1.09-1.21).

CONCLUSIONS AND RELEVANCE

Proton pump inhibitor use is associated with a higher risk of incident CKD. Future research should evaluate whether limiting PPI use reduces the incidence of CKD.

Proton pump inhibitors and risk of periampullary cancers--A nested case-control study

Considerable attention has been focused on long-term use of proton pump inhibitor (PPI) medications in relation to increased risk of cancer via stimulation of DNA-damaged cells. The aim of this study is to examine the dose-dependent effect of PPI on periampullary cancers in a national population-based cohort. A nested case-control analysis was constructed based on Taiwan's National Health Insurance Research Database and the Taiwan Cancer Registry between the years 2000 and 2010. Cases involving patients diagnosed with periampullary cancers were selected and controls were matched to cases according to age, sex and observational period. A "PPI user" was defined as any patient receiving more than 28 cumulative defined daily doses as measured by prescription drug claims. Conditional logistic regression analysis was conducted to calculate odds ratios (ORs) and 95% confidence intervals (CIs) according to the level of PPI exposure. A total of 7,681 cases and 76,762 matched controls were included with a mean follow-up period of 6.6 years (SD: 2.0). The odds of PPI exposure in patients with periampullary cancers were higher than that of control patients with an adjusted OR of 1.35 (95% CIs: 1.16-1.57). Our results also showed that PPI exposure was slightly linked to periampullary cancers in dose-dependent manner. A similar association was observed in patients who solely took PPI but no eradication therapy for Helicobacter pylori infection. Long-term PPI use was associated with an increased risk of periampullary cancers in the current population-based study. Physicians must weigh potential risks of long-term maintenance against therapeutic benefit.

From the nephrologist's point of view: diversity of causes and clinical features of acute kidney injury

Acute kidney injury (AKI) is a clinical syndrome with multiple entities. Although AKI implies renal damage, functional impairment or both, diagnosis is solely based on the functional parameters of serum creatinine and urine output. The latest definition was provided by the Kidney Disease Improving Global Outcomes (KDIGO) working group in 2012. Independent of the underlying disease, and even in the case of full recovery, AKI is associated with an increased morbidity and mortality. Awareness of the patient's individual risk profile and the diversity of causes and clinical features of AKI is pivotal for optimization of prophylaxes, diagnosis and therapy of each form of AKI. A differentiated and individualized approach is required to improve patient mortality, morbidity, long-term kidney function and eventually the quality of life. In this review, we provide an overview of the different clinical settings in which specific forms of AKI may occur and point out possible diagnostic as well as therapeutic approaches. Secifically AKI is discussed in the context of non-kidney organ failure, organ transplantation, sepsis, malignancy and autoimmune disease.

Before you call renal: Acute kidney injury for hospitalists

Acute kidney injury is a clinical problem of growing incidence in hospitalized patients. It increases the risk of poor outcomes, length of stay and the cost of hospitalization. Successful management of acute kidney injury requires early recognition and diagnosis through detailed medical history, careful physical exam, judicious use of laboratory and radiologic tests and timely renal consultation. Subsequent management is tailored to the likely mechanism of injury with emphasis on limiting both further injury and systemic consequences. A common sense approach to acute kidney injury is essential for hospitalists aiming to limit further injury, prevent acute complications and lessen the risk of chronic morbidity.

Proton pump inhibitors and the risk of acute kidney injury in older patients: a population-based cohort study

BACKGROUND

Proton pump inhibitors (PPIs) cause interstitial nephritis and are an underappreciated cause of acute kidney injury. We examined the risk of acute kidney injury and acute interstitial nephritis in a large population of older patients receiving PPIs.

METHODS

We conducted a population-based study involving Ontario residents aged 66 years and older who initiated PPI therapy between Apr. 1, 2002, and Nov. 30, 2011. We used propensity score matching to establish a highly comparable reference group of control patients. The primary outcome was hospital admission with acute kidney injury within 120 days, and a secondary analysis examined acute interstitial nephritis. We used Cox proportional hazards regression to adjust for differences between groups.

RESULTS

We studied 290 592 individuals who commenced PPI therapy and an equal number of matched controls. The rates of acute kidney injury (13.49 v. 5.46 per 1000 person-years, respectively; hazard ratio [HR] 2.52, 95% CI 2.27 to 2.79) and acute interstitial nephritis (0.32 vs. 0.11 per 1000 person-years; HR 3.00, 95% CI 1.47 to 6.14) were higher among patients given PPIs than among controls.

INTERPRETATION

In our study population of older adults, those who started PPI therapy had an increased risk of acute kidney injury and acute interstitial nephritis. These are potentially reversible conditions that may not be readily attributed to drug treatment. Clinicians should appreciate the risk of acute interstitial nephritis during treatment with PPIs, monitor patients appropriately and discourage the indiscriminate use of these drugs.

Changes in the aetiology, clinical presentation and management of acute interstitial nephritis, an increasingly common cause of acute kidney injury

Acute interstitial nephritis (AIN) is an important cause of acute kidney injury that has experienced significant epidemiological and clinical changes in the last years. The classical presentation, mostly induced by antibiotics and accompanied by evident hypersensitivity manifestations (skin rash, eosinophilia, fever) has been largely replaced by oligosymptomatic presentations that require a higher index of suspicion and are increasingly recognized in the elderly, having non-steroidal anti-inflammatory agents and proton pump inhibitors as frequent offending drugs. Drug-induced AIN continues to be the commonest type, but it requires a careful differential diagnosis with other entities (tubulointerstitial nephritis with uveitis syndrome, IgG4-related disease, drug reaction with eosinophilia and systemic symptom syndrome, sarcoidosis and other systemic diseases) that can also induce AIN. Cortico-dependant, relapsing AIN is a recently recognized entity that poses an important therapeutic challenge. Although corticosteroids are widely used in drug-induced AIN to speed kidney function recovery and avoid chronic kidney disease, their efficacy has not been tested by randomized controlled trials. New diagnostic tests and biomarkers, as well as prospective therapeutic studies are needed to improve AIN diagnosis and management.

Proton pump inhibitors and hospitalization with hypomagnesemia: a population-based case-control study

BACKGROUND

Some evidence suggests that proton pump inhibitors (PPIs) are an under-appreciated risk factor for hypomagnesemia. Whether hospitalization with hypomagnesemia is associated with use of PPIs is unknown.

METHODS AND FINDINGS

We conducted a population-based case-control study of multiple health care databases in Ontario, Canada, from April 2002 to March 2012. Patients who were enrolled as cases were Ontarians aged 66 years or older hospitalized with hypomagnesemia. For each individual enrolled as a case, we identified up to four individuals as controls matched on age, sex, kidney disease, and use of various diuretic classes. Exposure to PPIs was categorized according to the most proximate prescription prior to the index date as current (within 90 days), recent (within 91 to 180 days), or remote (within 181 to 365 days). We used conditional logistic regression to estimate the odds ratio for the association of outpatient PPI use and hospitalization with hypomagnesemia. To test the specificity of our findings we examined use of histamine H2 receptor antagonists, drugs with no causal link to hypomagnesemia. We studied 366 patients hospitalized with hypomagnesemia and 1,464 matched controls. Current PPI use was associated with a 43% increased risk of hypomagnesemia (adjusted odds ratio, 1.43; 95% CI 1.06-1.93). In a stratified analysis, the risk was particularly increased among patients receiving diuretics, (adjusted odds ratio, 1.73; 95% CI 1.11-2.70) and not significant among patients not receiving diuretics (adjusted odds ratio, 1.25; 95% CI 0.81-1.91). We estimate that one excess hospitalization with hypomagnesemia will occur among 76,591 outpatients treated with a PPI for 90 days. Hospitalization with hypomagnesemia was not associated with the use of histamine H2 receptor antagonists (adjusted odds ratio 1.06; 95% CI 0.54-2.06). Limitations of this study include a lack of access to serum magnesium levels, uncertainty regarding diagnostic coding of hypomagnesemia, and generalizability of our findings to younger patients.

CONCLUSIONS

PPIs are associated with a small increased risk of hospitalization with hypomagnesemia among patients also receiving diuretics. Physicians should be aware of this association, particularly for patients with hypomagnesemia. Please see later in the article for the Editors' Summary.

Renal dysfunction in end-stage liver disease and post-liver transplant

Renal dysfunction is a frequent complication in patients with end-stage liver disease awaiting orthotopic liver transplantation and in the post-liver transplant period. Although the stereotypical form of renal dysfunction is the hepatorenal syndrome, other causes of acute kidney injury in this population include prerenal azotemia and acute tubular necrosis. Renal injury in a patient with cirrhosis is associated with a poor prognosis.