Modeling and simulation of the effect of proton pump inhibitors on magnesium homeostasis. 1. Oral absorption of magnesium

Modeling Clinical Phenotype Variability: Consideration of Genomic Variations, Computational Methods, and Quantitative Proteomics

Advances in biomedical and computer technologies have presented the modeling community the opportunity for mechanistically modeling and simulating the variability in a disease phenotype or in a drug response. The capability to quantify response variability can inform a drug development program. Quantitative systems pharmacology scientists have published various computational approaches for creating virtual patient populations (VPops) to model and simulate drug response variability. Genomic variations can impact disease characteristics and drug exposure and response. Quantitative proteomics technologies are increasingly used to facilitate drug discovery and development and inform patient care. Incorporating variations in genomics and quantitative proteomics may potentially inform creation of VPops to model and simulate virtual patient trials, and may help account for, in a predictive manner, phenotypic variations observed clinically.

Proton-pump inhibitor use amongst patients with severe hypomagnesemia

Introduction: Long-term proton pump inhibitor (PPI) use has been associated with hypomagnesemia. It is unknown how frequently PPI use is implicated in patients with severe hypomagnesemia, and its clinical course or risk factors. Methods: All patients with severe hypomagnesemia from 2013 to 2016 in a tertiary center were assessed for likelihood of PPI-related hypomagnesemia using Naranjo algorithm, and we described the clinical course. The clinical characteristics of each case of PPI-related severe hypomagnesemia was compared with three controls on long-term PPI without hypomagnesemia, to assess for risk factors of developing severe hypomagnesemia. Results: Amongst 53,149 patients with serum magnesium measurements, 360 patients had severe hypomagnesemia (<0.4 mmol/L). 189 of 360 (52.5%) patients had at least possible PPI-related hypomagnesemia (128 possible, 59 probable, two definite). 49 of 189 (24.7%) patients had no other etiology for hypomagnesemia. PPI was stopped in 43 (22.8%) patients. Seventy (37.0%) patients had no indication for long-term PPI use. Hypomagnesemia resolved in most patients after supplementation, but recurrence was higher in patients who continued PPI, 69.7% versus 35.7%, p = 0.009. On multivariate analysis, risk factors for hypomagnesemia were female gender (OR 1.73; 95% CI: 1.17-2.57), diabetes mellitus (OR, 4.62; 95% CI: 3.05-7.00), low BMI (OR, 0.90; 95% CI: 0.86-0.94), high-dose PPI (OR, 1.96; 95% CI: 1.29-2.98), renal impairment (OR, 3.85; 95% CI: 2.58-5.75), and diuretic use (OR, 1.68; 95% CI: 1.09-2.61). Conclusion: In patients with severe hypomagnesemia, clinicians should consider the possibility of PPI-related hypomagnesemia and re-examine the indication for continued PPI use, or consider a lower dose.

Severe Hypomagnesemia Associated with the Long-term Use of the Potassium-competitive Acid Blocker Vonoprazan

Hypomagnesemia caused by a proton pump inhibitor (PPI) was first reported in 2006. We herein report a case of hypomagnesemia due to the long-term use of vonoprazan, a potassium-competitive acid blocker (P-CAB). A 66-year-old man was admitted to our hospital complaining of disturbance of consciousness with evidence of hypomagnesemia noted on blood testing. The long-term use of vonoprazan was considered the cause of his hypomagnesemia, so it was discontinued, after which the hypomagnesemia improved. Hypomagnesemia can be induced not only by PPI treatment but also following the long-term use of P-CAB.

Proton pump inhibitors and osteoporosis risk: exploring the role of TRPM7 channel

BACKGROUND

Long-term use of proton pump inhibitors (PPIs) has been linked to an increased risk of osteoporosis, with various indirect mechanisms so far identified. Although no direct underlying mechanism for effect on bone cells have been investigated with the use of PPIs. Melastatin-like transient receptor potential 7 (TRPM7)channel has been engaged in the proliferation of bone cells. TRPM7 channel is regulated by extracellular Mg²⁺ and Ca²⁺ level, that further encourages to analyse if any imbalance with pantoprazole usage could alter bone remodelling process mediated by TRPM7.

OBJECTIVES

The present study was conducted to investigate the effect of pantoprazole on the calcium and magnesium level, the cations involved in the bone remodelling process, as well as role of the TRPM7 channel in the proliferation of bone cells.

METHODS

A cytotoxicity study was carried out to study the effect of pantoprazole on the bone cell using MC3T3-E1 cell line, together with the expression of TRPM7 was determined post-pantoprazole treatment. An in vivo study in rats was carried out for estimation of Ca²⁺, Mg²⁺ and Ca²⁺/Mg²⁺ ratio as well as bone strength was measured over a duration of 4 weeks and 8 weeks with the treatment of pantoprazole. A pilot-scale clinical study was carried out in patients with a fracture to support the evidence of preliminary findings from in-vitro and in vivo studies.

RESULTS

MC3T3-E1 cell line treated with pantoprazole showed decreased cell viability in a dose-dependent manner and reduced expression of TRPM7 channel, evidencing interaction of TRPM7 and pantoprazole in the bone remodelling process. A pilot study conducted on 12 patients having major fractures showed changes in serum Mg²⁺ and Ca²⁺ levels over a period of 1 month as well as the animal study also showed ionic imbalance over 8-week treatment with pantoprazole. Bone density measured for the patient at the end of the 1-month treatment was found to be in the osteopenic category, together with the animal study which showed a decrease in femur bone strength for the animal treated with pantoprazole over a period of 8 weeks.

CONCLUSION

The study findings proved a negative impact of pantoprazole use on Ca²⁺ and Mg²⁺ levels, which can impact TRPM7-mediated bone remodelling which serves to be a possible mechanism for osteoporosis upon pantoprazole use.

Proton Pump Inhibitor Use, Hypomagnesemia and Risk of Cardiovascular Diseases: The Atherosclerosis Risk in Communities (ARIC) Study

GOALS

The goal of this study was to evaluate whether proton pump inhibitor (PPI) use is cross-sectionally associated with hypomagnesemia and whether hypomagnesemia mediates the prospective association between PPIs and cardiovascular disease (CVD) risk.

BACKGROUND

Use of PPIs has been associated with hypomagnesemia, primarily in case reports or within insurance databases. Both PPI use and low serum magnesium (Mg) have been associated with modestly higher CVD risk. Yet, the interrelation between PPI use and Mg in relation to CVD risk is unclear.

STUDY

The 4436 Atherosclerosis Risk in Communities participants without prevalent CVD at visit 5 (baseline, 2011-2013) were included. Multivariable relative risk regression was used for cross-sectional analyses between PPI and hypomagnesemia prevalence (≤0.75 mmol/L). Incident CVD (defined by atrial fibrillation, coronary heart disease, CVD mortality, heart failure, stroke) was identified through 2017. Multivariable Cox regression was used to examine the PPI-CVD association.

RESULTS

Participants were mean±SD aged 75±5 years; 63% were women, 23% Black, and 24% were PPI users. PPI users had 1.24-fold (95% confidence interval: 1.08-1.44) higher prevalence of hypomagnesemia than nonusers. Over a median 5 years of follow-up, 684 incident CVD events occurred. PPI users had higher CVD risk [hazard ratio (95% confidence interval) 1.31 (1.10-1.57)] than nonusers. The effect estimate was largely unchanged when hypomagnesemia was added to the model as a potential mediator.

CONCLUSIONS

In this elderly community-based study, PPI users had a higher prevalence of hypomagnesemia than in nonusers. PPI users also had higher CVD risk than nonusers; however, it appears unlikely that hypomagnesemia explains associations of PPIs with CVD risk.

Ca:Mg Ratio, APOE Cytosine Modifications, and Cognitive Function: Results from a Randomized Trial

BACKGROUND

Deterioration of ionized calcium (Ca2+) handling in neurons could lead to neurodegenerative disease. Magnesium (Mg) antagonizes Ca during many physiologic activities, including energy metabolism and catalyzation of demethylation from 5-methylcytosine(5-mC) to 5-hydroxymethylcytosine(5-hmC).

OBJECTIVE

To test the hypothesis that actively reducing the Ca:Mg intake ratio in the diet through Mg supplementation improves cognitive function, and to test whether this effect is partially mediated by modified cytosines in Apolipoprotein E (APOE).

METHODS

This study is nested within the Personalized Prevention of Colorectal Cancer Trial (PPCCT), a double-blind 2×2 factorial randomized controlled trial, which enrolled 250 participants from Vanderbilt University Medical Center. Target doses for both Mg and placebo arms were personalized.

RESULTS

Among those aged > 65 years old who consumed a high Ca:Mg ratio diet, we found that reducing the Ca:Mg ratio to around 2.3 by personalized Mg supplementation significantly improved cognitive function by 9.1% (p = 0.03). We also found that reducing the Ca:Mg ratio significantly reduced 5-mC at the cg13496662 and cg06750524 sites only among those aged > 65 years old (p values = 0.02 and 0.03, respectively). Furthermore, the beneficial effect of reducing the Ca:Mg ratio on cognitive function in those aged over 65 years was partially mediated by reductions in 5-mC levels (i.e., cg13496662 and cg06750524) in APOE (p for indirect effect = 0.05).

CONCLUSION

Our findings suggest that, among those age 65 and over with a high dietary Ca:Mg ratio, optimal Mg status may improve cognitive function partially through modifications in APOE methylation. These findings, if confirmed, have significant implications for the prevention of cognitive aging and Alzheimer's disease.Clinical Trial Registry number and website: #100106 https://clinicaltrials.gov/ct2/show/NCT03265483.

Prevalence and risk factors of long-term proton pump inhibitors-associated hypomagnesemia: a cross-sectional study in hospitalized patients

Proton pump inhibitors (PPI)-related hypomagnesemia is a potentially life-threatening adverse event first described in 2006. PPIs are widely used in the general population. Information regarding prevalence and risk factors is scarce. We conducted a cross-sectional study in inpatients to evaluate prevalence and associated factors with hypomagnesemia in chronic PPIs users. This is a cross-sectional study of hospitalized adult patients with chronic use of PPIs from January 01, 2012, to December 31, 2018. Chronic use was defined as taking PPIs at least 6 months before hospital admittance. Data were collected from informatized medical records from a University Hospital (Hospital Italiano de Buenos Aires). Hypomagnesemia was defined as a value equal to or less than 1.7 mg/dl. The first hospitalization measurement was retrieved. Thirty-six percent of patients (95% CI 30-43) with chronic PPI use presented hypomagnesemia at admission. Patients with hypomagnesemia presented a higher prevalence of chronic kidney disease (18.6% vs 8%, p < 0.05), more use of oral magnesium supplementation (20.9% vs 8%, p < 0.05), use of corticosteroids (32.6% vs 19.3%, p = 0.06) and calcineurin inhibitors (17.4% vs 6.7%, p < 0.05). Regarding laboratory findings, they presented lower hematocrit (28.7% vs 32.8%, p < 0.05), phosphatemia (3 mg/dl vs 3.4 mg/dl, p < 0.05), natremia (135 mg/dl vs 136 mg/dl, p < 0.05) and albumin levels (2.8 g/dl vs 3.2 g/dl p < 0.05) when compared to those who presented normomagnesemia. Hypocalcemia was more frequent among patients with hypomagnesemia (57% vs 38.7%, p < 0.05). In the multivariate analysis, hyponatremia, decreasing levels of hematocrit (odds ratio, OR 0.93-CI 95% 0.88-0.98) and malignant bone compromise (OR 2.83-CI 95% 1.04-7.7) were associated with hypomagnesemia. Adult patients with long-term use of PPIs have a high prevalence of hypomagnesemia. Increasing age, female sex, concomitant use of drugs that impair tubular function and chronic kidney disease may enhance this phenomenon. Anemia, hyponatremia and malignant bone compromise were associated factors with PPIs-related hypomagnesemia.

Is there a correlation between hypomagnesemia linked to long-term proton pump inhibitor use and the active agent?

BACKGROUND

One of the electrolyte disorders considered to be linked to proton pump inhibitors (PPI) use is hypomagnesemia. The aim of this study was to assess the incidence of hypomagnesemia linked to long-term PPI use and the correlation with active agents.

METHODS

The study included 305 patients aged over 18 years with PPI use of 1 year or longer and attending the internal diseases clinic for any reason from April 2019 to December 2019. A survey study was performed about the demographic characteristics and PPI use of patients. Laboratory parameters, such as the hemogram, magnesium, phosphorus, calcium and vitamin B12 concentrations were recorded. Magnesium concentrations were measured by a colorimetric method.

RESULTS

Of the patients 140 (45.9%) were female and 165 (54.1%) were male. The most commonly used PPI active agent was pantoprazole. The duration of PPI use varied from 1-25 years with a mean of 4.31 ± 4.52 years. Of the patients 51.5% reported no medication side effects. The most commonly observed side effect was constipation (n = 98, 32.1%). The mean magnesium concentration was 1.95 ± 0.02 mg/dL. Hypomagnesemia was identified in 65 (21.3%) patients and the incidence increased as age and duration of use increased. Patients using omeprazole had significantly lower magnesium levels compared to patients using pantoprazole, rabeprazole, esomeprazole and lansoprazole.

CONCLUSION

In light of the data obtained it was concluded that hypomagnesemia linked to PPI use is associated with the type of PPI. While patients using rabeprazole had the lowest rates, those using omeprazole had significantly higher rates of hypomagnesemia. Additionally, there was a proportional correlation between age and duration of use with the risk of development of hypomagnesemia.

Common Pitfalls in the Management of Patients with Micronutrient Deficiency: Keep in Mind the Stomach

Micronutrient deficiencies are relatively common, in particular iron and cobalamin deficiency, and may potentially lead to life-threatening clinical consequences when not promptly recognized and treated, especially in elderly patients. The stomach plays an important role in the homeostasis of some important hematopoietic micronutrients like iron and cobalamin, and probably in others equally important such as ascorbic acid, calcium, and magnesium. A key role is played by the corpus oxyntic mucosa composed of parietal cells whose main function is gastric acid secretion and intrinsic factor production. Gastric acid secretion is necessary for the digestion and absorption of cobalamin and the absorption of iron, calcium, and probably magnesium, and is also essential for the absorption, secretion, and activation of ascorbic acid. Several pathological conditions such as Helicobacter pylori-related gastritis, corpus atrophic gastritis, as well as antisecretory drugs, and gastric surgery may interfere with the normal functioning of gastric oxyntic mucosa and micronutrients homeostasis. Investigation of the stomach by gastroscopy plus biopsies should always be considered in the management of patients with micronutrient deficiencies. The current review focuses on the physiological and pathophysiological aspects of gastric acid secretion and the role of the stomach in iron, cobalamin, calcium, and magnesium deficiency and ascorbate homeostasis.

Proton-pump inhibitors associated with decreased urinary citrate excretion

INTRODUCTION

Proton-pump inhibitors (PPIs) may increase the risk of kidney stone formation, but the mechanism has not been elucidated. There is a paucity of literature evaluating the effects of PPIs on urinary metabolites and urine pH.

METHODS

We performed a retrospective review of nephrolithiasis patients treated at our institution and compared patients who were taking PPIs to those who were not at the time of their 24-h urine collections. Hierarchical multivariate linear regression was used to evaluate the independent relationship between PPI use and urinary mineral composition.

RESULTS

We identified 301 consecutive patients, 88 (29%) of whom were taking PPIs at the time of their 24-h urine collections. Patients taking PPIs were older and more likely to have medical comorbidities associated with metabolic syndrome such as hypertension, diabetes, and dyslipidemia (p < 0.01). Controlling for these factors, patients taking PPIs were found to have 12% lower 24-h urine citrate excretion (β =  - 0.12, ΔF = 4.24, p = 0.04). There were no other differences in urinary mineral composition between the groups.

CONCLUSION

Our findings suggest that patients who take PPIs regularly may be at risk for decreased urinary citrate excretion. The consequent decrease in urinary citrate may become clinically significant for patients with other predisposing factors for hypocitraturia.

Proton-Pump Inhibitors and Hypomagnesaemia in Kidney Transplant Recipients

Proton-pump inhibitors (PPIs) are commonly used after kidney transplantation and there is rarely an incentive to discontinue treatment. In the general population, PPI use has been associated with hypomagnesaemia. We aimed to investigate whether PPI use is associated with plasma magnesium, 24-h urinary magnesium excretion and hypomagnesaemia, in kidney transplant recipients (KTR). Plasma magnesium and 24-h urinary magnesium excretion were measured in 686 stable outpatient KTR with a functioning allograft for ≥1 year from the TransplantLines Food and Nutrition Biobank and Cohort-Study (NCT02811835). PPIs were used by 389 KTR (56.6%). In multivariable linear regression analyses, PPI use was associated with lower plasma magnesium (β: −0.02, P = 0.02) and lower 24-h urinary magnesium excretion (β: −0.82, P < 0.001). Moreover, PPI users had a higher risk of hypomagnesaemia (plasma magnesium <0.70 mmol/L), compared with non-users (Odds Ratio (OR): 2.12; 95% confidence interval (CI) 1.43–3.15, P < 0.001). This risk tended to be highest among KTR taking high PPI dosages (>20 mg omeprazole Eq/day) and was independent of adjustment for potential confounders (OR: 2.46; 95% CI 1.32–4.57, P < 0.005). No interaction was observed between PPI use and the use of loop diuretics, thiazide diuretics, tacrolimus, or diabetes (P_interaction > 0.05). These results demonstrate that PPI use is independently associated with lower magnesium status and hypomagnesaemia in KTR. The concomitant decrease in urinary magnesium excretion indicates that this likely is the consequence of reduced intestinal magnesium absorption. Based on these results, it might be of benefit to monitor magnesium status periodically in KTR on chronic PPI therapy.

Proton pump inhibitors and hypomagnesemia: A meta-analysis of observational studies

BACKGROUND

Previous meta-analyses have suggested that there might be an association between the use of proton pump inhibitors (PPIs) and the development of hypomagnesemia, although the conclusions were no definitive.

METHODS

To provide an update on this topic, we performed a meta-analysis of all observational studies that examined the association between the use of PPIs and the development of hypomagnesemia. A literature search was conducted in MEDLINE, Scopus and Cochrane Central Register of Controlled Trials (January 1970 to June 2018) to identify observational studies that examined the association between the use of PPIs and the incidence and prevalence of hypomagnesemia.

STUDY ELIGIBILITY CRITERIA

In the absence of randomized controlled trials, we focused primarily on observational studies, including cross-sectional, case-control, retrospective, and prospective cohort studies. There was no limitation on sample size or study duration. Random-effect models meta-analyses were used to compute pooled unadjusted and adjusted odds ratios (ORs) for binary variables.

RESULTS

Sixteen observational studies were identified, including 13 cross-sectional studies, 2 case-control studies, and 1 cohort study, with a total of 131,507 patients. The pooled percentage of PPI users was 43.6% (95% confidence interval [CI] 25.0%, 64.0%). Among PPI users, 19.4% (95% CI 13.8%, 26.5%) had hypomagnesemia compared to 13.5% (95% CI 7.9%, 22.2%) among nonusers. By meta-analysis, PPI use was significantly associated with hypomagnesemia, with a pooled unadjusted OR of 1.83 (95% CI 1.26, 2.67; P = .002) and a pooled adjusted OR of 1.71 (95% CI 1.33, 2.19; P < .001). In subgroup analyses, high-dose PPI use was associated with higher odds for hypomagnesemia relative to low-dose PPI use (pooled adjusted OR 2.13; 95% CI 1.26, 3.59; P = .005).

CONCLUSION

Our findings are in support of the results of the previous meta-analyses. Furthermore, we found a dose-response between the PPI use and development of hypomagnesemia.

Insights into Effects/Risks of Chronic Hypergastrinemia and Lifelong PPI Treatment in Man Based on Studies of Patients with Zollinger-Ellison Syndrome

The use of proton pump inhibitors (PPIs) over the last 30 years has rapidly increased both in the United States and worldwide. PPIs are not only very widely used both for approved indications (peptic ulcer disease, gastroesophageal reflux disease (GERD), Helicobacter pylori eradication regimens, stress ulcer prevention), but are also one of the most frequently off-label used drugs (25–70% of total). An increasing number of patients with moderate to advanced gastroesophageal reflux disease are remaining on PPI indefinitely. Whereas numerous studies show PPIs remain effective and safe, most of these studies are <5 years of duration and little data exist for >10 years of treatment. Recently, based primarily on observational/epidemiological studies, there have been an increasing number of reports raising issues about safety and side-effects with very long-term chronic treatment. Some of these safety issues are related to the possible long-term effects of chronic hypergastrinemia, which occurs in all patients taking chronic PPIs, others are related to the hypo-/achlorhydria that frequently occurs with chronic PPI treatment, and in others the mechanisms are unclear. These issues have raised considerable controversy in large part because of lack of long-term PPI treatment data (>10–20 years). Zollinger–Ellison syndrome (ZES) is caused by ectopic secretion of gastrin from a neuroendocrine tumor resulting in severe acid hypersecretion requiring life-long antisecretory treatment with PPIs, which are the drugs of choice. Because in <30% of patients with ZES, a long-term cure is not possible, these patients have life-long hypergastrinemia and require life-long treatment with PPIs. Therefore, ZES patients have been proposed as a good model of the long-term effects of hypergastrinemia in man as well as the effects/side-effects of very long-term PPI treatment. In this article, the insights from studies on ZES into these controversial issues with pertinence to chronic PPI use in non-ZES patients is reviewed, primarily concentrating on data from the prospective long-term studies of ZES patients at NIH.

Does the use of proton pump inhibitors increase the risk of hypomagnesemia: An updated systematic review and meta-analysis

BACKGROUND

Proton pump inhibitors (PPIs) are commonly used in the treatment of acid-related diseases; however, the association between the use of PPIs and potential risk of hypomagnesemia is controversial.

METHODS

In the present study, databases including PubMed, EMBASE, MEDLINE, PsycINFO, CINAHL, the Cochrane Library, and 4 Chinese databases were searched since the inception until April 2018. Previous observational studies on the incidence of hypomagnesemia in individuals exposed to PPIs were included.

RESULTS

This systematic review involved 15 studies including 129,347 participants, and the sample size varied from 52 to 95,205. Meta-analysis of 14 studies indicated that the use of PPIs increased the risk of hypomagnesemia [RR, 1.44, 95% CI, 1.13-1.76; I, 85.2%]. Subgroup analysis revealed that the use of PPI was not associated with the incidence of hypomagnesemia in outpatients [RR, 1.49; 95% CI, 0.83-2.14; I, 41.4%] and hospitalized patients [RR, 1.05; 95% CI, 0.81-1.29; I, 62.1%], respectively. The use of PPIs was not related to the risk of hypomagnesemia based on the cut-off values of 1.8 mg/dL [RR, 1.73; 95% CI, 0.87-2.58; I, 65.2%], 1.7 mg/dL [RR, 1.48; 95% CI, 0.90-2.06; I, 87.6%], and 1.6 mg/dL [RR, 0.98; 95% CI, 0.69-1.27; I, 67.9%].

CONCLUSION

The association between the exposure to PPI and the incidence of hypomagnesemia remained unclear. Due to the remarkable heterogeneity in previous studies, a definitive conclusion could not be drawn. Further research should be conducted to investigate the relationship between the use of individual PPI and potential risk of hypomagnesemia, and a dose-response analysis may be required.

The inhibitory role of purinergic P2Y receptor on Mg2+ transport across intestinal epithelium-like Caco-2 monolayer

The mechanism of proton pump inhibitors (PPIs) suppressing intestinal Mg2+ uptake is unknown. The present study aimed to investigate the role of purinergic P2Y receptors in the regulation of Mg2+ absorption in normal and omeprazole-treated intestinal epithelium-like Caco-2 monolayers. Omeprazole suppressed Mg2+ transport across Caco-2 monolayers. An agonist of the P2Y2 receptor, but not the P2Y4 or P2Y6 receptor, suppressed Mg2+ transport across control and omeprazole-treated monolayers. Omeprazole enhanced P2Y2 receptor expression in Caco-2 cells. Forskolin and P2Y2 receptor agonist markedly enhanced apical HCO3- secretion by control and omeprazole-treated monolayers. The P2Y2 receptor agonist suppressed Mg2+ transport and stimulated apical HCO3- secretion through the Gq-protein coupled-phospholipase C (PLC) dependent pathway. Antagonists of cystic fibrosis transmembrane conductance regulator (CFTR) and Na+-HCO3- cotransporter-1 (NBCe1) could nullify the inhibitory effect of P2Y2 receptor agonist on Mg2+ transport across control and omeprazole-treated Caco-2 monolayers. Our results propose an inhibitory role of P2Y2 on intestinal Mg2+ absorption.

Y. Chiu D, Kalra PA, Green D. Prevalence and outcomes of proton pump inhibitor associated hypomagnesemia in chronic kidney disease

Background

Proton pump inhibitors (PPIs) are one of the most widely prescribed medications across the world. PPIs have been associated with significant electrolyte abnormalities including hypomagnesaemia. We explored the prevalence of PPI associated hypomagnesaemia (PPIH) in different Chronic Kidney Disease (CKD) stages, in different PPI agents, and the impact of PPIH on survival in CKD.

Methods

This was a subgroup analysis of the Salford Kidney Study, a prospective, observational, longitudinal study of non-dialysis CKD patients. Patients with outpatient magnesium samples obtained between 2002 and 2013 were included in the analysis. The prevalence hypomagnesaemia based on mean values over 12 months as well as ‘ever’ hypomagnesaemia were investigated.

Results

1,230 patients were included in this analysis, mean age 64.3± 32.3 years and mean eGFR 29.2±15.8 ml/min/1.73m². Mean serum magnesium in those on PPI was significantly lower than those not on PPI overall (0.85±0.10 mmolL^-1 versus 0.79±0.12 mmolL^-1 respectively, p<0.001). This finding was maintained at all CKD stages. The adjusted odds ratio (OR) for mean hypomagnesaemia in PPI use was 1.12 (95% CI 1.06–1.18) p = <0. ‘Ever hypomagnesaemia’ had an OR of 1.12 (95% CI 1.07–1.16) p = <0.001. The expected rise in serum magnesium with declining eGFR was not observed in those on a PPI but was seen in those not on PPI. There was no difference in serum magnesium between PPI drugs. Thiazide diuretics were also associated with hypomagnesaemia independent of PPI use. Cox regression analysis demonstrated no reduction in survival in patients with PPI associated hypomagnesaemia.

Conclusion

No specific PPI drugs show a favourable profile in regards of risk for hypomagnesaemia in CKD. Avoiding concurrent use of PPI and thiazide may be of value in patients with hypomagnesaemia.

Bidirectional association between fibromyalgia and gastroesophageal reflux disease: two population-based retrospective cohort analysis

Fibromyalgia (FM) tends to coexist with gastroesophageal reflux disease (GERD). This retrospective cohort study was conducted to determine the bidirectional association between FM and GERD, using a nationwide database, the National Health Insurance of Taiwan. We established 2 study arms, including 35,117 patients with FM in arm 1 and 34,630 patients with GERD in arm 2, newly diagnosed between 2000 and 2010. For each study arm, we randomly selected 4-fold subjects with neither FM nor GERD from the same database, frequency matched by sex, age, and diagnosis date, as the respective control cohorts. Incidence of GERD in arm 1 and incidence of FM in arm 2 were estimated by the end of 2011. The overall incidence of GERD was 1.6-fold greater in the FM cohort than in the non-FM cohort (12.0 and 7.61 per 1000 person-years, crude hazard ratio [HR] = 1.58, 95% confidence interval [CI] = 1.51-1.66), with an adjusted HR (aHR) of 1.27 (95% CI = 1.22-1.33) after controlling for sex, age, comorbidities, and medications. The GERD cohort ultimately had a 1.5-fold higher incidence of FM than the non-GERD cohort (5.76 vs 3.96 per 1000 person-years), with an aHR of 1.44 (95% CI = 1.29-1.60). The present study suggests a bidirectional relationship between FM and GERD. There is a greater risk of developing GERD for patients with FM than developing FM for patients with GERD.

Magnesium Balance in Chronic and End-Stage Kidney Disease

This article explores the effects of CKD and end-stage kidney disease on magnesium balance. In CKD, there is decreased glomerular filtration of magnesium. Decreased tubular reabsorption can compensate to a degree, but once CKD stage 4 is reached there is a tendency toward hypermagnesemia. In dialysis, magnesium balance is dependent on the constituents of the dialysate that the blood is exposed to. The concentration of dialysate magnesium is just one of the factors that need to be considered. During transplantation, there are particular effects of immunosuppressants that can affect the magnesium balance and need to be considered by the clinician.

Advantages and Disadvantages of Long-term Proton Pump Inhibitor Use

Proton pump inhibitors (PPIs) potently inhibit gastric acid secretion and are widely used for treatment of acid-related diseases including gastroesophageal reflux disease and secondary prevention of aspirin/NSAID-induced ulcers. Although clinically important adverse effects of PPIs can occur, just as with other drugs, those are not frequently observed during or after administration. Thus, PPIs are regarded as relatively safe and considered to be clinically beneficial. Recently, PPIs have become frequently administered to patients with functional gastrointestinal diseases or primary prevention of drug-related gastroduodenal damage, even though their beneficial effects for those conditions have not been fully confirmed. PPIs tend to be given for conditions in which the necessity of the drug has not been clarified, thus otherwise rare adverse effects are presented as clinically relevant. Although several PPI-related adverse effects have been reported, their clinical relevance is not yet clear, since the evidence reported in those studies is not at a high enough level, as the majority are based on retrospective observational studies and the reported hazard ratios are low. It is important to administer PPIs only for patients who will gain a substantial clinical benefit and to continue to investigate their adverse effects with high quality prospective studies.

Proton Pump Inhibitors: More Indigestion than Relief?

Proton pump inhibitors (PPIs) are widely prescribed to treat a number of gastrointestinal (GI) disorders due to excessive acid production. While effective and safe, adverse renal effects have been increasingly described in epidemiological literature. The most well-documented adverse renal outcome is acute interstitial nephritis; however, association with overall acute kidney injury has also been recently reported. Recently, two observational studies have linked PPI use with chronic kidney disease. Finally, hypomagnesemia is another reported complication and is thought to be resulting from GI loss of magnesium. This study will critically review literature on the effect of PPIs on the kidney.

Electrolyte disorders with platinum-based chemotherapy: mechanisms, manifestations and management

Platinum chemotherapy, particularly cisplatin, is commonly associated with electrolyte imbalances, including hypomagnesemia, hypokalemia, hypophosphatemia, hypocalcemia and hyponatremia. The corpus of literature on these dyselectrolytemias is large; the objective of this review is to synthesize the literature and summarize the mechanisms responsible for these particular electrolyte disturbances in the context of platinum-based treatment as well as to present the clinical manifestations and current management strategies for oncologists and primary care physicians, since the latter are increasingly called on to provide care for cancer patients with medical comorbidities. Correct diagnosis and effective treatment are essential to improved patient outcomes.

Mechanistic Oral Absorption Modeling and Simulation for Formulation Development and Bioequivalence Evaluation: Report of an FDA Public Workshop

On May 19, 2016, the US Food and Drug Administration (FDA) hosted a public workshop, entitled “Mechanistic Oral Absorption Modeling and Simulation for Formulation Development and Bioequivalence Evaluation.”1 The topic of mechanistic oral absorption modeling, which is one of the major applications of physiologically based pharmacokinetic (PBPK) modeling and simulation, focuses on predicting oral absorption by mechanistically integrating gastrointestinal transit, dissolution, and permeation processes, incorporating systems, active pharmaceutical ingredient (API), and the drug product information, into a systemic mathematical whole‐body framework.2

Clinical aspects of magnesium physiology in patients on dialysis

Magnesium balance is infrequently discussed in the dialysis population, and the clinical consequences of derangements in magnesium homeostasis are incompletely understood. There is an association between hypomagnesemia and adverse outcomes including increases in cardiovascular disease and mortality, while elevated magnesium levels have also been linked with complications such as osteomalacia. In this review, we discuss the features of magnesium physiology relevant to dialysis patients and provide an updated summary of the literature linking magnesium derangements with bone disease, cardiovascular disease, sudden cardiac death, and mortality.

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.

Physiologically Based Pharmacokinetic and Absorption Modeling for Osmotic Pump Products

Physiologically based pharmacokinetic (PBPK) and absorption modeling approaches were employed for oral extended-release (ER) drug products based on an osmotic drug delivery system (osmotic pumps). The purpose was to systemically evaluate the in vivo relevance of in vitro dissolution for this type of formulation. As expected, in vitro dissolution appeared to be generally predictive of in vivo PK profiles, because of the unique feature of this delivery system that the in vitro and in vivo release of osmotic pump drug products is less susceptible to surrounding environment in the gastrointestinal (GI) tract such as pH, hydrodynamic, and food effects. The present study considered BCS (Biopharmaceutics Classification System) class 1, 2, and 3 drug products with half-lives ranging from 2 to greater than 24 h. In some cases, the colonic absorption models needed to be adjusted to account for absorption in the colon. C _max (maximum plasma concentration) and AUCt (area under the concentration curve) of the studied drug products were sensitive to changes in colon permeability and segmental GI transit times in a drug product-dependent manner. While improvement of the methodology is still warranted for more precise prediction (e.g., colonic absorption and dynamic movement in the GI tract), the results from the present study further emphasized the advantage of using PBPK modeling in addressing product-specific questions arising from regulatory review and drug development.

Hypomagnesemia as a predictor of mortality in hemodialysis patients and the role of proton pump inhibitors: A cross-sectional, 1-year, retrospective cohort study

Introduction This study aimed to evaluate the association between proton pump inhibitor (PPI) use and serum magnesium levels, and the role of hypomagnesemia and PPI use as a risk factor for mortality in hemodialysis patients. Methods An observational study, including a cross-sectional and 1-year retrospective cohort study. The study comprised 399 hemodialysis patients at a single center, and was conducted from January to September 2014. Multiple linear regression analysis was used to investigate the independent relationship between serum magnesium levels and baseline demographic and clinical variables, including PPI and histamine-2 receptor antagonist use. Cox regression model was used to identify lower serum magnesium level and PPI as a predictor of 1-year mortality. Findings Serum magnesium levels were lower with PPI use than non-PPI use (2.39 ± 0.36 vs. 2.56 ± 0.39 mg/dL, P < 0.001). Multiple linear regression analysis showed that PPI use, low serum albumin levels, and low serum potassium and high-sensitivity C-reactive protein (hs-CRP) levels were significantly associated with low serum magnesium levels. A total of 29 deaths occurred during the follow-up period. According to Cox regression analysis stratified by hs-CRP, only high serum hs-CRP levels (>4.04 mg/L) in association with low serum magnesium levels was an independent risk factor for 1-year mortality (hazard ratio: 2.92; 95% CI: 1.53-6.40, P < 0.001). Discussion Serum magnesium levels are lower in PPI use. In the inflammatory state, a low serum magnesium level is a significant predictor of mortality in hemodialysis patients.

Is there a relationship between hypomagnesemia and proton-pump inhibitors in patients on chronic hemodialysis?

AIM

We investigated the association among long-term proton-pump inhibitors (PPIs) use with serum magnesium (Mg) levels in chronic hemodialysis (HD) patients, as well as possible association among PPI use and increased risk of cardiovascular (CVD) morbidity in HD patients.

METHODS

Of 418 HD patients that were screened for inclusion, 136 were excluded due to incomplete medical data, duration of renal replacement therapy (RRT) for less than 12months, use of Mg-based-phosphate binders or other Mg-based medications or either to presence of chronic increased GI losses. Among 282 patients included in the study, 170 patients were on PPIs.

RESULTS

Serum Mg levels were significantly lower among PPI users vs. non-users (0.94±0.2 vs. 1.03±0.2mmol/L; p<0.0001). The median duration of PPI use was 27±9.6months (range from 12 to 108) and it was not significantly associated with Mg levels (r=0.116; p=0.167). Additionally, residual renal function didn't show a significant correlation with Mg concentration (r=-0.102; p=NS) in both groups of patients. The use of PPIs was an independent and strong predictor of low Mg concentrations even in multivariate analysis (OR 3.05; 95% CI 1.2498-7.4594, p=0.01). On the other hand, the daily dose of PPIs was not associated with low Mg levels. PPI users had a higher rate of adverse CVD events during the 1 year of follow-up in comparison to non-PPI users but that difference wasn't statistically significant (17.6% vs. 10.7%; p=0.110).

CONCLUSION

We have found a significant association between PPI use and lower serum Mg levels in chronic HD patients.

Proton-pump inhibitor-induced hypomagnesemia: Current research and proposed mechanisms

Since the early reports nearly a decade ago, proton-pump inhibitor-induced hypomagnesemia (PPIH) has become a well-recognized phenomenon. While many observational studies in the inpatient and outpatient populations have confirmed the association of PPI exposure and serum magnesium concentrations, there are no prospective, controlled studies to support causation. Molecular mechanisms of magnesium transporters, including the pH-dependent regulation of transient receptor potential melastatin-6 transporters in the colonic enterocyte, have been proposed to explain the effect of PPIs on magnesium reabsorption, but may be a small part of a more complicated interplay of molecular biology, pharmacology, and genetic predisposition. This review explores the current state of research in the field of PPIH and the proposed mechanisms of this effect.

Nutritional consequences of long-term acid suppression; are they clinically important?

PURPOSE OF REVIEW

As acid suppression therapies with proton pump inhibitors are an extremely common practice for common acid-related diseases, there has been increased scrutiny on the safety of this class of therapy.

RECENT FINDINGS

There have been increasing reports of allegation of harm with the sustained use of proton pump inhibitors, in particular with potential adverse effects on vitamin and mineral absorption. This has prompted a number of product label changes directed by the US Food and Drug Administration, raising concerns for ongoing continued use among clinicians and patients.

SUMMARY

This review highlights the most recent information around these controversies and provides evidence summaries to help guide care providers in their care plans as well as discussions with patients.

Proton Pump Inhibitor Use and Magnesium Concentrations in Hemodialysis Patients: A Cross-Sectional Study

Magnesium concentration is a proven predictor of mortality in hemodialysis patients. Recent reports have indicated that proton pump inhibitor (PPI) use affects serum magnesium levels, however few studies have investigated the relationship between PPI use and magnesium levels in hemodialysis patients. This study aimed to clarify the association between PPI use and serum magnesium levels in hemodialysis patients. We designed this cross sectional study and included 1189 hemodialysis patients in stable condition. Associations between PPI and magnesium-related factors, as well as other possible confounders, were evaluated using a multiple regression model. We defined hypomagnesemia as a value < 2.0 mg/dL, and created comparable logistic regression models to assess the association between PPI use and hypomagnesemia. PPI use is associated with a significantly lower mean serum magnesium level than histamine 2 (H2) receptor antagonists or no acid-suppressive medications (mean [SD] PPI: 2.52 [0.45] mg/dL; H2 receptor antagonist: 2.68 [0.41] mg/dL; no acid suppressive medications: 2.68 [0.46] mg/dL; P = 0.001). Hypomagnesemia remained significantly associated with PPI (adjusted OR, OR: 2.05; 95% CI: 1.14–3.69; P = 0.017). PPI use is associated with an increased risk of hypomagnesemia in hemodialysis patients. Future prospective studies are needed to explore magnesium replacement in PPI users on hemodialysis.

Dietary Inulin Fibers Prevent Proton-Pump Inhibitor (PPI)-Induced Hypocalcemia in Mice

Background

Proton-pump inhibitor-induced hypomagnesemia (PPIH) is the most recognized side effect of proton-pump inhibitors (PPIs). Additionally, PPIH is associated with hypocalcemia and hypokalemia. It is hypothesized that PPIs reduce epithelial proton secretion and thereby increase the pH in the colon, which may explain the reduced absorption of and Mg²⁺ and Ca²⁺. Fermentation of dietary oligofructose-enriched inulin fibers by the microflora leads to acidification of the intestinal lumen and by this enhances mineral uptake. This study aimed, therefore, to improve mineral absorption by application of dietary inulin to counteract PPIH.

Methods

Here, C57BL/J6 mice were supplemented with omeprazole and/or inulin. Subsequently, Mg²⁺ and Ca²⁺ homeostasis was assessed by means of serum, urine and fecal electrolyte measurements. Moreover, the mRNA levels of magnesiotropic and calciotropic genes were examined in the large intestine and kidney by real-time PCR.

Results

Treatment with omeprazole significantly reduced serum Mg²⁺ and Ca²⁺ levels. However, concomitant addition of dietary inulin fibers normalized serum Ca²⁺ but not serum Mg²⁺ concentrations. Inulin abolished enhanced expression of Trpv6 and S100g in the colon by omeprazole. Additionally, intestinal and renal mRNA levels of the Trpm6 gene were reduced after inulin intake.

Conclusions

This study suggests that dietary inulin counteracts reduced intestinal Ca²⁺ absorption upon PPI treatment. In contrast, inulin did not increase intestinal absorption of Mg²⁺ sufficiently to recover serum Mg²⁺. The clinical potential of dietary inulin treatment should be the subject of future studies.

The relationship between proton pump inhibitor use and serum magnesium concentration among hemodialysis patients: a cross-sectional study

Background

Observational data suggest that serum magnesium (Mg) concentration is inversely related to vascular calcification and hyperparathyroidism among patients with end-stage renal disease (ESRD). In recent years, there have been several case reports of hypomagnesemia due to use of proton-pump inhibitors (PPI), with the hypomagnesemia attributed to inappropriate gastrointestinal (GI) Mg loss. We hypothesized that the tendency to GI Mg loss is more common than is currently reported. Since patients with ESRD have little to no renal Mg loss to affect serum Mg concentration, dialysis patients are an interesting population in whom to study the relationship between PPI use and serum Mg levels.

Methods

Using a single-center cross-sectional design, we studied 155 prevalent hemodialysis (HD) patients. Serum Mg concentration for each patient was determined based on the mean of 3 consecutive serum Mg levels drawn at 6 week intervals. PPI use at the time of the blood tests was documented. The relationship between PPI use and Mg concentration was determined in unadjusted analyses, as well as after adjustment for age, gender, race, cause of ESRD, diabetes, time on HD and dialysate Mg concentration.

Results

55 % of patients were on PPIs at the time of the study. The majority of patients (62 %) used a dialysate Mg (in mmol/L) of 0.5, and the remainder (38 %) used a dialysate Mg of 0.375. Serum Mg levels were significantly lower among PPI users vs. non-users (0.93 vs. 1.02 mmol/L, p < 0.001). This finding persisted after stratifying for dialysate Mg concentration, and after multivariable adjustment (p < 0.001). In addition, more PPI users vs. non-users had a Mg level < 1 mmol/L (79 % vs. 43 %) and a Mg level < 0.8 mmol/L (16 % vs. 4 %). There was a non-significant trend toward increased time on PPI being associated with lower serum Mg levels (p = 0.067).

Conclusion

Among HD patients, PPI users have lower serum Mg levels as compared with non-users. Further research is required to determine whether the magnitude of change in Mg levels among PPI users is associated with adverse outcomes.

Proton-pump inhibitor use is associated with lower urinary magnesium excretion

AIMS

Although multiple recent studies have confirmed an association between chronic proton-pump inhibitor (PPI) use and hypomagnesaemia, the physiologic explanation for this association remains uncertain. To address this, we investigated the association of PPI use with urinary magnesium excretion.

METHODS

We measured 24-hour urine magnesium excretion in collections performed for nephrolithiasis evaluation in 278 consecutive ambulatory patients and determined PPI use from contemporaneous medical records.

RESULTS

There were 50 (18%) PPI users at the time of urine collection. The mean daily urinary magnesium was 84.6 ± 42.8 mg in PPI users, compared with 101.2 ± 41.1 mg in non-PPI users (P = 0.01). In adjusted analyses, PPI use was associated with 10.54 ± 5.30 mg/day lower daily urinary magnesium excretion (P = 0.05). Diuretic use did not significantly modify the effect of PPI on urinary magnesium. As a control, PPI use was not associated with other urinary indicators of nutritional intake.

CONCLUSIONS

Our findings suggest that PPI use is associated with lower 24-hour urine magnesium excretion. Whether this reflects decreased intestinal uptake due to PPI exposure, or residual confounding due to decreased magnesium intake, requires further study.

Proton pump inhibitors and hypomagnesemia in the general population: a population-based cohort study

BACKGROUND

Proton pump inhibitor (PPI) use has been associated with hypomagnesemia in case reports and hospital-based cohort studies. Our objective was to determine whether PPI use is associated with hypomagnesemia in the general population and whether this is also found in histamine 2 receptor antagonist (H2RA) users.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

9,818 individuals from the general population (Rotterdam Study).

PREDICTOR

PPI use and H2RA use compared to no use.

OUTCOMES & MEASUREMENTS

Serum magnesium and hypomagnesemia (serum magnesium ≤ 1.44 mEq/L). Analyses were adjusted for age, sex, body mass index, kidney function, comorbid conditions, and alcohol and diuretic use.

RESULTS

Serum magnesium level was 0.022 mEq/L lower in PPI users (n=724; 95% CI, -0.032 to -0.014 mEq/L) versus those with no use. PPI use was associated with increased risk of hypomagnesemia (n=36; OR, 2.00; 95% CI, 1.36-2.93) compared to no use. Effect modification was found between the use of PPIs and loop diuretics; in participants using loop diuretics (n=270), PPI use was associated with a further increased risk of hypomagnesemia (n=5; OR, 7.22; 95% CI, 1.69-30.83) compared to no use. The increased risk with PPIs was only seen after prolonged use (range, 182-2,618 days; OR, 2.99; 95% CI, 1.73-5.15). Including dietary magnesium intake into the model did not alter results (available for 2,504 participants, including 231 PPI users). H2RA users (n=250) also had a lower serum magnesium level (-0.016 [95% CI, -0.032 to -0.002] mEq/L) and increased risk of hypomagnesemia (n=12; OR, 2.00; 95% CI, 1.08-3.72) compared to those with no use, but no interaction with loop diuretics.

LIMITATIONS

Cross-sectional analysis with single serum magnesium measurement.

CONCLUSIONS

PPI use is associated with hypomagnesemia in the general population. Prolonged PPI use and concomitant loop diuretic use are associated with a stronger risk increase. Similar but weaker associations were found in H2RA users, except for interaction with loop diuretics.

'Lemonade Legs': Why do Some Patients Get Profound Hypomagnesaemia on Proton-Pump Inhibitors?

Proton pump inhibitors (PPIs) are widely used though an association with hypomagnesaemia and hypocalcaemia has only been described since 2006. Patients typically present after years of stable dosing with musculoskeletal, neurological or cardiac arrhythmic symptoms, but it is likely that many cases are under-recognised. Magnesium levels resolve rapidly on discontinuation of PPI therapy and hypomagnesaemia recurs rapidly on rechallenge with any agent in the class. The cellular mechanisms of magnesium homeostasis are increasingly being understood, including both passive paracellular absorption through claudins and active transcellular transporters, including the transient receptor potential channels (TRPM6) identified in the intestine and nephron. PPIs may alter luminal pH by modulating pancreatic secretions, affecting non-gastric H+K+ATPase secretion, altering transporter transcription or channel function. A small reduction in intestinal absorption appears pivotal in causing cumulative deficiency. Risk factors have been associated to help identify patients at risk of this effect but clinical vigilance remains necessary for diagnosis.

The association between the use of proton pump inhibitors and the risk of hypomagnesemia: a systematic review and meta-analysis

Background

Although many case reports have described patients with proton pump inhibitor (PPI)-induced hypomagnesemia, the impact of PPI use on hypomagnesemia has not been fully clarified through comparative studies. We aimed to evaluate the association between the use of PPI and the risk of developing hypomagnesemia by conducting a systematic review with meta-analysis.

Methods

We conducted a systematic search of MEDLINE, EMBASE, and the Cochrane Library using the primary keywords “proton pump,” “dexlansoprazole,” “esomeprazole,” “ilaprazole,” “lansoprazole,” “omeprazole,” “pantoprazole,” “rabeprazole,” “hypomagnesemia,” “hypomagnesaemia,” and “magnesium.” Studies were included if they evaluated the association between PPI use and hypomagnesemia and reported relative risks or odds ratios or provided data for their estimation. Pooled odds ratios with 95% confidence intervals were calculated using the random effects model. Statistical heterogeneity was assessed with Cochran’s Q test and I² statistics.

Results

Nine studies including 115,455 patients were analyzed. The median Newcastle-Ottawa quality score for the included studies was seven (range, 6–9). Among patients taking PPIs, the median proportion of patients with hypomagnesemia was 27.1% (range, 11.3–55.2%) across all included studies. Among patients not taking PPIs, the median proportion of patients with hypomagnesemia was 18.4% (range, 4.3–52.7%). On meta-analysis, pooled odds ratio for PPI use was found to be 1.775 (95% confidence interval 1.077–2.924). Significant heterogeneity was identified using Cochran’s Q test (df = 7, P<0.001, I² = 98.0%).

Conclusions

PPI use may increase the risk of hypomagnesemia. However, significant heterogeneity among the included studies prevented us from reaching a definitive conclusion.

Impact of proton pump inhibitor use on magnesium homoeostasis: a cross-sectional study in a tertiary emergency department

BACKGROUND

To date, the use of proton pump inhibitors (PPIs) has been associated with a low risk of hypomagnesaemia and associated adverse outcomes. We hypothesised that a better risk estimate could be derived from a large cohort of outpatients admitted to a tertiary emergency department (ED).

METHODS

A cross-sectional study was performed in 5118 patients who had measurements of serum magnesium taken on admission to a large tertiary care ED between January 2009 and December 2010. Hypomagnesaemia was defined as a serum magnesium concentration < 0.75 mmol/l. Demographical data, serum electrolyte values, data on medication, comorbidities and outcome with regard to length of hospital stay and mortality were analysed.

RESULTS

Serum magnesium was normally distributed where upon 1246 patients (24%) were hypomagnesaemic. These patients had a higher prevalence of out-of-hospital PPI use and diuretic use when compared with patients with magnesium levels > 0.75 mmol/l (both p < 0.0001). In multivariable regression analyses adjusted for PPIs, diuretics, renal function and the Charlson comorbidity index score, the association between use of PPIs and risk for hypomagnesaemia remained significant (OR = 2.1; 95% CI: 1.54-2.85). While mortality was not directly related to low magnesium levels (p = 0.67), the length of hospitalisation was prolonged in these patients even after adjustment for underlying comorbid conditions (p < 0.0001).

CONCLUSION

Use of PPIs predisposes patients to hypomagnesaemia and such to prolonged hospitalisation irrespective of the underlying morbidity, posing a critical concern.

From hypomagnesaemia to Zollinger-Ellison syndrome: an adverse effect of a proton pump inhibitor

We describe the case of a 53-year-old man who presented with abdominal pain, diarrhoea and hypomagnesaemia. The hypomagnesaemia proved to be due to gastrointestinal loss as urinary fractional excretion was very low, suggesting non-renal loss. Common causes were discarded and the hypomagnesaemia was attributed to chronic use of the proton pump inhibitor, omeprazole. As such, omeprazole was discontinued and an H2 blocker was given. Several days later the patient presented with upper gastrointestinal bleeding. CT scan demonstrated marked enlargement of the duodenum and proximal jejunum, and abnormal thickening and enhancement of the bowel wall. Urgent oesophagogastroduodenoscopy revealed coffee-ground and bloody contents in the distal oesophagus and stomach, and numerous ulcers along the duodenum and jejunum. A positron emission tomography-CT scan using GA 68-DOTANOC demonstrated increased uptake in the gastroduodenum junction, suggesting a neuroendocrine tumour. Pancreaticoduodenectomy was performed and tumour cells stained positive for gastrin, confirming the tentative diagnosis of Zollinger-Ellison syndrome.

Hypomagnesaemia associated with long-term use of proton pump inhibitors

Hypomagnesaemia and associated hypocalcaemia and hypoparathyroidism have been increasingly recognised as rare long-term side-effects of proton pump inhibitors (PPIs). The PPIs may inhibit active magnesium (Mg) absorption by interfering with transcellular transient receptor potential melastatin-6 and -7 (TRPM 6 and 7) channels. More recent cell culture studies have suggested concomitant inhibition of passive Mg absorption by omeprazole. After being treated with a range of PPIs, the four patients in our case series developed hypomagnesaemia, which responded to withdrawal of therapy and initiation of Mg replacement. Their clinical course and management demonstrate key aspects of hypomagnesaemia associated with long-term use of PPIs.

Hypomagnesemia in hemodialysis patients: role of proton pump inhibitors

BACKGROUND

Recent observations have associated hypomagnesemia with increased risk of cardiovascular morbidity and mortality in hemodialysis patients.

METHODS

We did a 3-month chart review of 62 chronic hemodialysis patients at a single US hospital. All were dialyzed using a dialysate [Mg] of 0.75-1.0 mEq/l. Patients were divided into two groups: hypomagnesemic (mean predialysis plasma [Mg] <1.5 mEq/l) and non-hypomagnesemic (mean predialysis plasma [Mg] ≥1.5 mEq/l).

RESULTS

All patients were male; mean age was 64.3 ± 8.7 years and the majority (73%) diabetic. 24 patients (39%) had hypomagnesemia and 38 (61%) were not hypomagnesemic. There were no significant differences between the two groups in age, diabetes status, blood pressure, duration of dialysis, plasma calcium, phosphorus, albumin, intact parathyroid hormone (PTH), dialysis adequacy (Kt/V), or dietary protein intake (as estimated by normalized protein catabolic rate, nPCR). However, use of proton pump inhibitors (PPIs) was significantly associated with hypomagnesemia (plasma [Mg] 1.48 ± 0.16 mEq/l in the PPI group vs. 1.65 ± 0.26 mEq/l in the non-PPI group, p = 0.007). Adjustment for age, diabetes status, duration of dialysis, plasma albumin, Kt/V, nPCR, and diuretic use did not affect the association between PPI use and hypomagnesemia.

CONCLUSIONS

Use of PPIs in patients dialyzed using a dialysate [Mg] of 0.75-1.0 mEq/l is associated with hypomagnesemia. We suggest monitoring plasma [Mg] in patients taking PPIs, with discontinuation of the medication if possible and/or adjustment of dialysate [Mg] to normalize plasma [Mg].

Severe symptomatic hypomagnesaemia induced by the chronic use of proton pump inhibitors: a case report of a patient with Zollinger-Ellison syndrome

The association between proton pump inhibitor (PPI) therapy and hypomagnesaemia has been recognized since 2006. We report the case of a 51-year-old woman who developed severe symptomatic hypomagnesaemia after a long-term PPI therapy given for recurrent peptic ulcer disease. Hypomagnesaemia could only partially be resolved during substitution therapy, but was corrected after withdrawal of the PPI. Recurrence of hypomagnesaemia occurred after retreatment with PPIs, supporting the causal relationship. An underlying gastric acid hypersecretion (Zollinger-Ellison syndrome) was highly suspected and eventually controlled by a combination of a histamine 2-receptor antagonist and octreotide, without the need for further PPI therapy after 2 years of follow-up.

TRPM6

TRPM6 is a bifunctional protein comprising a TRP cation channel segment covalently linked to an α-type serine/threonine protein kinase. TRPM6 is expressed in the intestinal and renal epithelial cells. Loss-of-function mutations in the human TRPM6 gene give rise to hypomagnesemia with secondary hypocalcemia (HSH), suggesting that the TRPM6 channel kinase plays a central role in systemic Mg(2+) homeostasis. In contrast, Trpm6 null mice show a delay in prenatal development, neural tube defects, and prenatal death. Possible functions of TRPM6 in prenatal and adult organisms will be discussed in this chapter.

Systems pharmacology modeling: an approach to improving drug safety

Advances in systems biology in conjunction with the expansion in knowledge of drug effects and diseases present an unprecedented opportunity to extend traditional pharmacokinetic and pharmacodynamic modeling/analysis to conduct systems pharmacology modeling. Many drugs that cause liver injury and myopathies have been studied extensively. Mitochondrion-centric systems pharmacology modeling is important since drug toxicity across a large number of pharmacological classes converges to mitochondrial injury and death. Approaches to systems pharmacology modeling of drug effects need to consider drug exposure, organelle and cellular phenotypes across all key cell types of human organs, organ-specific clinical biomarkers/phenotypes, gene-drug interaction and immune responses. Systems modeling approaches, that leverage the knowledge base constructed from curating a selected list of drugs across a wide range of pharmacological classes, will provide a critically needed blueprint for making informed decisions to reduce the rate of attrition for drugs in development and increase the number of drugs with an acceptable benefit/risk ratio.

Omeprazole enhances the colonic expression of the Mg(2+) transporter TRPM6

Proton pump inhibitors (PPIs) are potent blockers of gastric acid secretion, used by millions of patients suffering from gastric acid-related complaints. Although PPIs have an excellent safety profile, an increasing number of case reports describe patients with severe hypomagnesemia due to long-term PPI use. As there is no evidence of a renal Mg²⁺ leak, PPI-induced hypomagnesemia is hypothesized to result from intestinal malabsorption of Mg²⁺. The aim of this study was to investigate the effect of PPIs on Mg ²⁺homeostasis in an in vivo mouse model. To this end, C57BL/6J mice were treated with omeprazole, under normal and low dietary Mg²⁺ availability. Omeprazole did not induce changes in serum Mg²⁺ levels (1.48 ± 0.05 and 1.54 ± 0.05 mmol/L in omeprazole-treated and control mice, respectively), urinary Mg²⁺ excretion (35 ± 3 μmol/24 h and 30 ± 4 μmol/24 h in omeprazole-treated and control mice, respectively), or fecal Mg²⁺ excretion (84 ± 4 μmol/24 h and 76 ± 4 μmol/24 h in omeprazole-treated and control mice, respectively) under any of the tested experimental conditions. However, omeprazole treatment did increase the mRNA expression level of the transient receptor potential melastatin 6 (TRPM6), the predominant intestinal Mg²⁺ channel, in the colon (167 ± 15 and 100 ± 7 % in omeprazole-treated and control mice, respectively, P < 0.05). In addition, the expression of the colonic H⁺,K⁺-ATPase (cHK-α), a homolog of the gastric H⁺,K⁺-ATPase that is the primary target of omeprazole, was also significantly increased (354 ± 43 and 100 ± 24 % in omeprazole-treated and control mice, respectively, P < 0.05). The expression levels of other magnesiotropic genes remained unchanged. Based on these findings, we hypothesize that omeprazole inhibits cHK-α activity, resulting in reduced extrusion of protons into the large intestine. Since TRPM6-mediated Mg²⁺absorption is stimulated by extracellular protons, this would diminish the rate of intestinal Mg²⁺ absorption. The increase of TRPM6 expression in the colon may compensate for the reduced TRPM6 currents, thereby normalizing intestinal Mg²⁺ absorption during omeprazole treatment in C57BL/6J mice, explaining unchanged serum, urine, and fecal Mg²⁺ levels.

Magnesium in health and disease

Mammalian cells tightly regulate cellular Mg(2+) content through a variety of transport and buffering mechanisms under the control of various hormones and cellular second messengers. The effect of these hormones and agents results in dynamic changes in the total content of Mg(2+) being transported across the cell membrane and redistributed within cellular compartments. The importance of maintaining proper cellular Mg(2+) content optimal for the activity of various cellular enzymes and metabolic cycles is underscored by the evidence that several diseases are characterized by a loss of Mg(2+) within specific tissues as a result of defective transport, hormonal stimulation, or metabolic impairment. This chapter will review the key mechanisms regulating cellular Mg(2+) homeostasis and their impairments under the most common diseases associated with Mg(2+) loss or deficiency.