Omeprazole-induced interstitial nephritis

Prescription medication use and antinuclear antibodies in the United States, 1999-2004

BACKGROUND

Clinical reports link specific medications with the development of antinuclear antibodies (ANA), but population-based evidence is limited.

OBJECTIVE

The present study investigated associations between prescription medication use and ANA in a representative sample of the adult noninstitutionalized US population, first focusing on medications previously related to ANA and then considering all medications reported in the National Health and Nutrition Examination Survey (NHANES).

METHODS

Based on NHANES data (1999-2004) for 3608 adults (ages ≥18 years), we estimated odds ratios (ORs) and 95% confidence intervals (CIs) to assess associations between recent medication use and ANA (overall and in sex and age subgroups), adjusted for potential confounders and the survey sampling design.

RESULTS

We found no evidence that most medications previously associated with ANA in specific individuals were risk factors for ANA in the general population, although statistical power was limited for some medications. Overall, ANA were less prevalent in adults who recently used any prescription medications compared with those who did not (OR = 0.73; CI = 0.57,0.93), and likewise several classes of medications were inversely associated with ANA, including hormones (OR = 0.73; CI = 0.55,0.98), thiazide diuretics (OR = 0.43; CI = 0.24,0.79), sulfonylureas (OR = 0.41; CI = 0.19,0.89), and selective serotonin reuptake inhibitor antidepressants (OR = 0.65; CI = 0.42,0.98). Positive associations with ANA were seen for loop diuretics (OR = 1.72; CI = 1.03,2.88) in all adults, and for benzodiazepines (OR = 2.11; CI = 1.09,4.10) and bronchodilators (OR = 1.83; CI = 1.00,3.38) in older (ages ≥60) adults. Estrogens were positively associated with ANA in older women (OR = 1.80; CI = 1.00,3.23) but inversely associated with ANA in younger (ages 18-59) women (OR = 0.43; CI = 0.20,0.93). Regarding individual medications, ANA were positively associated with ciprofloxacin (OR = 4.23; CI = 1.21,14.8), furosemide (OR = 1.79; CI = 1.09,2.93), and omeprazole (OR = 2.05; CI = 1.03,4.10) in all adults, and with salmeterol (OR = 3.76; CI = 1.66,8.52), tolterodine (OR = 6.64; CI = 1.45,30.5), and triamterene (OR = 3.10; CI = 1.08,8.88) in older adults. Also, in younger adults, hydrochlorothiazide was inversely associated with ANA (OR = 0.44; CI = 0.20,0.98).

CONCLUSIONS

Our findings in the general population do not confirm most clinically reported positive associations between specific medications and ANA in some individuals. However, novel positive ANA associations with other medications, as well as unexplained inverse associations with certain classes of medications and overall medication use, deserve further research to clarify the possible roles of medications as risk and protective factors in the development of autoantibodies and autoimmune disease.

Proton Pump Inhibitors and Kidney Disease - GI Upset for the Nephrologist?

Widely regarded as safe and effective, proton pump inhibitors (PPIs) are among the most commonly used medications in the world today. However, a spate of observational studies suggest an association between PPI use and adverse events, including infection, bone fracture, and dementia. This review details evidence linking the use of PPI therapy to the development of kidney disease, including early case reports of acute interstitial nephritis and subsequent large observational studies of acute kidney injury (AKI), chronic kidney disease (CKD), and end-stage renal disease (ESRD). The majority of studies showed higher risk of kidney outcomes among persons prescribed PPI medications, with effect sizes that were slightly higher for AKI (∼2-3-fold) compared to CKD and ESRD (1.2-1.8-fold). Although observational pharmaco-epidemiology studies are limited by the possibility of residual confounding and confounding by indication, many of the described studies conducted rigorous sensitivity analyses aimed at minimizing these biases, including new-user design, comparison to similar agents (e.g., histamine₂ receptor antagonists), and evaluation for a dose-response, with robust results. Given the widespread use of PPIs, even a small effect on kidney outcomes could result in large public health burden. Timely cessation of PPI therapy when there is no clear indication for use might reduce the population burden of kidney disease.

Gastroesophageal reflux disease

GERD is a common chronic gastrointestinal disorder, and its prevalence in Asia is increasing. Classical symptoms of heartburn and regurgitation are common presentations. There is no standard criterion for the diagnosis of GERD, and 24-h pH monitoring lacks sensitivity in NERD. Furthermore, diagnostic studies for gastroesophageal reflux disease have several limitations. A short course of PPI is often used in clinical practice as a diagnostic test for gastroesophageal reflux disease. Elderly patients with GERD usually present with atypical manifestations, and they tend to develop more severe disease. PPI remains the mainstay of treatment for GERD. In a subset of patients who wish to discontinue maintenance treatment, anti-reflux surgery is a therapeutic option.

Review: treatment of gastroesophageal reflux disease in the elderly

The prevalence of gastroesophageal reflux disease (GERD) increases with age; older patients are more likely to develop severe disease. Common symptoms of GERD in the elderly include dysphagia, vomiting, and respiratory problems. Older patients are more likely to require aggressive therapy, and usually their management is compounded by the presence of comorbidities and consumption of various medications. Proton pump inhibitors are the mainstay of GERD treatment in the elderly because of their profound and consistent acid suppressive effect. Overall, proton pump inhibitors seem to be safe for both short- and long-term therapy in elderly patients with GERD. Antireflux surgery may be safe and effective in a subset of elderly patients with GERD.

Safety of the long-term use of proton pump inhibitors

The proton pump inhibitors (PPIs) as a class are remarkably safe and effective for persons with peptic ulcer disorders. Serious adverse events are extremely rare for PPIs, with case reports of interstitial nephritis with omeprazole, hepatitis with omeprazole and lansoprazole, and disputed visual disturbances with pantoprazole and omeprazole. PPI use is associated with the development of fundic gland polyps (FGP); stopping PPIs is associated with regression of FGP. In the absence of Helicobacter pylori infection, the long-term use of PPIs has not been convincingly proven to cause or be associated with the progression of pre-existing chronic gastritis or gastric atrophy or intestinal metaplasia. Mild/modest hypergastrinemia is a physiological response to the reduction in gastric acid secretion due to any cause. The long-term use of PPIs has not been convincingly proven to cause enterochromaffin-like cell hyperplasia or carcinoid tumors. PPIs increase the risk of community acquired pneumonia, but not of hospital acquired (nosocomial) pneumonia. There is no data to support particular care in prescribing PPI therapy due to concerns about risk of hip fracture with the long-term use of PPIs. Long-term use of PPIs does not lead to vitamin B12 deficiencies, except possibly in the elderly, or in persons with Zollinger-Ellison Syndrome who are on high doses of PPI for prolonged periods of time. There is no convincingly proven data that PPIs increase the risk of Clostridium difficile-associated diarrhea in persons in the community. The discontinuation of PPIs may result in rebound symptoms requiring further and even continuous PPI use for suppression of symptoms. As with all medications, the key is to use PPIs only when clearly indicated, and to reassess continued use so that long-term therapy is used judiciously. Thus, in summary, the PPIs are a safe class of medications to use long-term in persons in whom there is a clear need for the maintenance of extensive acid inhibition.

Systematic review: Proton pump inhibitor-associated acute interstitial nephritis

BACKGROUND

A number of recent case reports and case series suggest that proton pump inhibitors may cause acute interstitial nephritis.

AIM

To establish the nature of the relationship (cause or association) between proton pump inhibitor use and development of interstitial nephritis.

DATA COLLECTION

Two researchers independently searched electronic databases (MEDLINE, EMBASE, GOOGLE, LILACS, COCHRANE) for articles from 1970 to 2006, including all study designs, populations and languages. Two independent reviewers assessed study quality and collected the data.

SELECTION CRITERIA

absence of baseline renal failure, development of interstitial nephritis after proton pump inhibitor exposure, nephritis confirmed by creatinine plus either renal biopsy or recurrence upon reinitiating proton pump inhibitor.

RESULTS

Sixty four cases (60% females, mean age 78 years) of proton pump inhibitor-associated interstitial nephritis were found, 60 included in this review (59 confirmed by renal biopsy, one by recurrence upon reinitiating proton pump inhibitor). The most common symptoms were non-specific. The mean proton pump inhibitor treatment duration before diagnosing nephritis was 13 weeks, average recovery time was 35.5 weeks, one patient required permanent dialysis, there were no deaths.

CONCLUSION

Proton pump inhibitor-related interstitial nephritis is rare, idiosyncratic and difficult to predict. It requires a high level of clinical suspicion. While there is not sufficient evidence to establish a causal relationship with certainty, there does appear to be a low-prevalence association.

Proton pump inhibitors and acute interstitial nephritis

BACKGROUND & AIMS

Proton pump inhibitors (PPIs) are a widely prescribed class of drugs, and their usage worldwide is increasing. Although well-tolerated, there have been case reports and a recent case series implicating these drugs in acute interstitial nephritis (AIN) and progression to acute renal failure (ARF). The aim of this study was to investigate how widespread this complication is in Australia, to identify which PPIs are implicated, and to establish whether PPI-induced AIN is a class effect.

METHODS

We undertook a retrospective case review of potential cases at 2 teaching hospitals and a review of registry data from the Therapeutic Goods Administration of Australia (TGA). Parameters sought included the drug implicated, concurrent medications, symptoms, signs, serum creatinine, and time of onset after prescription.

RESULTS

We identified 18 cases of biopsy-proven PPI-induced AIN causing ARF in the retrospective case review, which is the largest hospital-based case series to date. The TGA registry data identified an additional 31 cases of "biopsy proven interstitial nephritis." An additional 10 cases of "suspected interstitial nephritis," 20 cases of "unclassified acute renal failure," and 26 cases of "renal impairment" were also identified. All 5 commercially available PPIs were implicated in these cases.

CONCLUSION

With the ever more widespread use of this class of medications, PPI-induced AIN is likely to become more frequent. There is now evidence to incriminate all the commercially available PPIs, suggesting there is a class effect. Failure to recognize this entity might have catastrophic long-term consequences including chronic kidney disease. Increased awareness might facilitate more rapid diagnosis and management of this potentially reversible condition.

Acute Interstitial Nephritis Due to Pantoprazole

OBJECTIVE:

To describe what is believed, as of November 4, 2003, to be the first case published in the literature of acute interstitial nephritis (AIN) due to pantoprazole.

CASE SUMMARY:

A 77-year-old white woman presented to the hospital with elevated serum creatinine, oliguria for the past 24 hours, arthralgia, fatigue, fever, and bilateral flank pain. The patient had initiated treatment with oral pantoprazole 40 mg/d for gastroesophageal reflux 2 months prior to admission. After 5 weeks of therapy, she stopped taking pantoprazole due to general malaise. Upon admission, all home medications, including pantoprazole, were reinitiated based on the patient's medication list. Serum creatinine increased to 6.1 mg/dL on day 4 of admission from a baseline of 1.0 mg/dL. Pantoprazole therapy was promptly discontinued, and prednisone 40 mg/d was initiated. Urinalysis revealed eosinophils, and a subsequent renal biopsy confirmed a diagnosis of AIN. The serum creatinine level gradually declined over 2 weeks, and the patient was discharged home with a serum creatinine level of 1.6 mg/dL. The Naranjo probability scale suggests a highly probable relationship between AIN and pantoprazole therapy in this patient.

DISCUSSION:

Drug hypersensitivity reactions are the most common cause of AIN. There have been several reported cases of omeprazole-induced AIN. Although there are very few prospective data on the efficacy of treatment of drug-induced AIN, corticosteroids may have a role in recovery of renal function. Prednisone doses of 1 mg/kg/d have been suggested.

CONCLUSIONS:

Physicians should be aware that drug-induced AIN can be associated with proton-pump inhibitors. Early detection of this rare adverse reaction may prevent acute renal insufficiency.

Treatment of acid-related diseases in the elderly with emphasis on the use of proton pump inhibitors

Proton pump inhibitors (PPIs) have revolutionised the treatment of acid-related disorders, and they have also made it possible to define the spectrum of acid inhibition required for optimal treatment in each disorder. Five PPIs are now available: the older drugs, omeprazole, lansoprazole and pantoprazole, and the two newest, rabeprazole and esomeprazole. These agents have predominantly been developed in the younger adult population, and data for the elderly population are limited. Subtle differences have emerged between the old and the new PPIs in their pharmacokinetic, pharmacodynamic and efficacy profiles. The degree of clinical relevance of these differences in the adult population is in question. However, according to this review, based on the available data for the elderly and by inference from the adult population, the differences are highly relevant in the elderly population. Studies of the pharmacokinetics of older PPIs demonstrated considerable variation in drug clearance that was reflected in a wide range of efficacy related to acid suppression with standard dosages. The newer PPIs offer several advantages over older agents, particularly in terms of rapid, profound and consistent acid inhibition. Consistent acid inhibition is particularly important in the elderly since clinical response is often difficult to judge in this patient group. An individual's cytochrome P450 (CYP) 2C19 genotype predicts the degree of acid suppression and consequently the clinical efficacy of the PPIs. The older PPIs are predominantly metabolised by CYP2C19, with this being of more importance for omeprazole and lansoprazole than pantoprazole. The hepatic metabolism of rabeprazole is predominantly by nonenzymatic reactions and minimally by CYP-mediated reactions, which therefore confers an advantage over older PPIs in that genetic polymorphisms for CYP2C19 do not significantly influence rabeprazole clearance, clinical efficacy or potential for drug interactions. The metabolism of esomeprazole involves CYP2C19 but to a lesser extent than its predecessor omeprazole. Furthermore, esomeprazole has a more rapid onset of action and less variation in clearance rates than omeprazole. Drug clearance decreases with age independently of CYP2C19 status, exaggerating some of the differences between the PPIs and increasing the risk of drug interactions.

Acute interstitial nephritis due to omeprazole

Omeprazole is a proton pump inhibitor that is used commonly in the treatment of acid-peptic disorders. Although omeprazole is generally well tolerated, serious adverse effects such as renal failure have been reported. Thus far, 17 cases of acute interstitial nephritis (AIN) secondary to omeprazole have been described. Another case of AIN is described in a 36-yr-old woman presenting with nausea, vomiting, weight loss, and a rising serum creatinine concentration. Omeprazole therapy had ceased 2 wk before admission. AIN was diagnosed by renal biopsy and corticosteroid therapy was initiated. After 4 wk of therapy the serum creatinine concentration had normalized. Among the reported cases in the literature, AIN was diagnosed after an average of 2.7 months of therapy with 20-40 mg of omeprazole daily. Recurrence was universal on rechallenge. Common symptoms included fatigue, fever, anorexia, and nausea. The classic triad of fever, rash, and eosinophilia was uncommon. Typical laboratory features included hematuria, proteinuria, pyuria, eosinophilia, and anemia. Management consisted of withdrawal of omeprazole and corticosteroid therapy in some patients. All but one patient recovered normal renal function. Corticosteroid therapy was well tolerated and may have been beneficial.

Review article: comparison of the pharmacokinetics, acid suppression and efficacy of proton pump inhibitors

Proton pump inhibitors have dramatically influenced the management of acid-peptic disorders in recent years. They all have a broadly similar mechanism of action and are extensively metabolized in the liver via cytochromes P450 2C19 and 3A4. There is some variation in their potential for drug interactions due to differences in enzyme inhibition. Relatively few serious adverse effects have been reported for the proton pump inhibitors. Comparative studies of acid suppression suggest that lansoprazole and pantoprazole have a potency similar to that of omeprazole on a mg for mg basis; however, rabeprazole may have a greater potency than omeprazole. Lansoprazole and rabeprazole display a more rapid onset of maximal acid suppression than the other proton pump inhibitors. Comparative studies using proton pump inhibitors for the treatment of reflux oesophagitis, duodenal ulcer healing and Helicobacter pylori eradication show little overall difference in outcome between the proton pump inhibitors when used in their standard doses. Lansoprazole and rabeprazole provide earlier and better symptom relief than the other proton pump inhibitors in some studies of peptic ulcer treatment. The few studies of gastric ulcer treatment suggest that there is an advantage in using the proton pump inhibitors that have a higher standard daily dose.