Influence of proton pump inhibitors and histamine H2 receptor antagonists on serum phosphorus level control by calcium carbonate in patients undergoing hemodialysis: a retrospective medical chart review

De-Prescribing Proton Pump Inhibitors in Patients With End Stage Kidney Disease: A Quality Improvement Project

Background:

Proton pump inhibitors (PPIs) are widely prescribed and may be associated with harm; hypomagnesemia and reduced effectiveness of calcium carbonate phosphate binders may be important in end-stage kidney disease (ESKD).

Objectives:

Our objectives included (1) discontinuing PPIs and H2 blockers and (2) assessing the impact on serum magnesium and markers of mineral metabolism.

Design:

Prospective cohort.

Setting:

Satellite hemodialysis unit of a tertiary care hospital.

Patients:

Incident and prevalent patients with ESKD treated with hemodialysis.

Measurements:

We assessed the impact of stopping PPI/H2 blockers in patients who did not have an absolute indication as per guidelines in the general population; serum magnesium, calcium, and phosphate were measured before and approximately 8 weeks later. Analysis of variance (ANOVA) test and Kruskal-Wallis was used to describe the population. Wilcoxon signed rank test for the paired change scores (from pre to post)

Methods:

The electronic medical record (EMR) was extensively searched for absolute indications for a PPI. Results were reviewed with the primary nephrology team before approaching patients about stopping the PPI. Basic demographic information and select medications were also collected.

Results:

Electronic medical records were reviewed for 179 patients, 74 had a PPI or H2 antagonist or both on their medication list (43%); 23 (31%) were assessed as appropriate. After primary team and patient review, 29 patients agreed to a trial of PPI withdrawal. Fourteen patients restarted their PPI, most for gastroesophageal reflux disease. Three patients had a GI bleed, 1 fatally. Serum calcium (P = .17) and the dose of phosphate binders (P = .075) did not change but serum phosphate increased (1.55 [0.29] to 1.85 [0.34] mmol/L; P = .0005). Serum magnesium also increased (1.01 [0.16] to 1.06 [0.14] mmol/L; P = .01).

Limitations:

Small patient numbers and observational nature of the study does not establish causation in this population at high risk to experience a gastrointestinal bleed.

Conclusions:

Our results suggest that PPI deprescribing as recommended in the general population may be associated with harm in patients with ESKD and requires further study.

Trial Registration:

Not registered.

Safety and effectiveness of lanthanum carbonate for hyperphosphatemia in chronic kidney disease (CKD) patients: a meta-analysis

Objective

The aim of this study was to determine the efficacy and safety of lanthanum carbonate (LC) versus calcium salts, non-LC phosphate binders (PBs), sevelamer, or placebo in patients with chronic kidney disease (CKD).

Materials and methods

A literature search on PubMed, Embase, and Cochrane Library databases was conducted up to 18 June 2021. Data acquisition and quality assessment were performed by two reviewers. Meta-analysis was performed to evaluate the serum biochemical parameters, adverse events, and patient-level outcomes of LC, non-LC PBs, and sevelamer for hyperphosphatemia in patients with CKD. Heterogeneity across studies was assessed utilizing the I² statistic and Q-test, and a random effect model was selected to calculate the pooled effect size.

Results

A total of 26 randomized, controlled trials and 3 observational studies were included. Compared to the other groups, better control effect of serum phosphorus (RR = 2.68, p < 0.001), reduction in serum phosphorus (95%CI = −1.93, −0.99; p < 0.001), Ca × P (95%CI = −13.89, −2.99; p = 0.002), serum intact parathyroid hormone levels (95%CI = −181.17, −3.96, p = 0.041) were found in LC group. Besides, reduced risk of various adverse effects, such as hypotension, abdominal pain, diarrhea, dyspepsia, and a score of coronary artery calcification were identified with LC in comparison to calcium salt, non-LC PBs, or placebo group. Significantly lower risk in mortality with LC treatment vs. non-LC PBs was observed, while no significant difference was identified between LC and calcium salt groups.

Conclusion

LC might be an alternative treatment for hyperphosphatemia in patients with CKD considering its comprehensive curative effect.

Phosphate binders in chronic kidney disease: an updated narrative review of recent data

Chronic kidney disease (CKD) is frequently accompanied by hyperphosphatemia. High serum phosphate usually requires dietary measures, adequate dialysis prescription and/or phosphate binders. For this narrative review a PubMed searched was undertaken to identify new publications on phosphate binders that had been published between January 2015 and July 2019. The present review summarizes this most recent information on dietary measures and their problems in treating hyperphosphatemia in CKD patients, overall effects of phosphate binders on cardiovascular mortality and morbidity, adherence to phosphate binder therapy as well as new data on specific aspects of the various phosphate binders on the market: calcium-containing phosphate binders, polymeric phosphate binders (sevelamer, bixalomer, colestilan), magnesium-containing phosphate binders, lanthanum carbonate, ferric citrate, sucroferric oxyhydroxide, and new compounds in development, in particular drugs targeting intestinal phosphate transporters.

A comparison between the combined effect of calcium carbonate with sucroferric oxyhydroxide and other phosphate binders: an in vitro and in vivo experimental study

Background

Approximately 30% of patients on dialysis received combination therapy for their phosphate binder prescription; however, few studies for combined effects of phosphate binders are reported. For the purpose of evaluating the efficacy of combination therapy, we compared the efficacy of sucroferric oxyhydroxide (PA21) combined with calcium carbonate with that of lanthanum carbonate hydrate, sevelamer hydrochloride, and ferric citrate hydrate combined with calcium carbonate.

Methods

For in vitro studies, calcium carbonate and the other phosphate binders alone or in combination were stirred in phosphate solution at pH 2–8 for 2 h. After centrifuging the suspension, the phosphorus level in the supernatant was determined. For in vivo studies, rats were orally administered calcium carbonate and the other phosphate binders (except for sevelamer hydrochloride) alone or in combination, followed by oral administration of phosphate solution adjusted to pH 2 or 7. Serum samples were collected from the rats at predetermined timepoints and the serum phosphorus levels were determined and analyzed using a two-way analysis of variance.

Results

In the in vitro study, the measured phosphate-binding capacity of combining sevelamer hydrochloride, PA21, and lanthanum carbonate hydrate with calcium carbonate was approximately equal to or greater than the theoretical values under most conditions. Furthermore, these combined effects were insensitive to pH in that order. The measured phosphate-binding capacity of ferric citrate hydrate combined with calcium carbonate was smaller than the theoretical values, and the combination did not exhibit efficacy under any of the tested conditions. In the in vivo study, the combined effect of PA21 and calcium carbonate at both pH values and that of lanthanum carbonate hydrate and calcium carbonate at pH 2 were additive. In contrast, the combined effect of lanthanum carbonate hydrate and calcium carbonate at pH 7 and that of ferric citrate hydrate and calcium carbonate at pH 2 were antagonistic.

Conclusions

These results suggest that coadministration of PA21 and calcium carbonate showed good and relatively stable efficacy throughout the range of the gastrointestinal pH and that combining lanthanum carbonate hydrate and ferric citrate hydrate with calcium carbonate may not produce the expected efficacy under certain conditions.

Influence of pH and phosphate concentration on the phosphate binding capacity of five contemporary binders. An in vitro study

AIM

Hyperphosphataemia is associated with increased mortality and morbidity in end stage renal disease. Despite phosphate binder therapy, a large proportion of patients do not reach the treatment target. In five contemporary binders we explored the influence of pH and phosphate concentration on phosphate binding. This interaction could be of relevance in clinical practice.

METHODS

Phosphate binding was quantified in vitro in 25 mL of purified water containing phosphate concentrations of 10, 15 and 20 mM and baseline pH values of 3.0 or 6.0, with a binder over 6 h. Lanthanum carbonate, calcium acetate/magnesium carbonate, sevelamer carbonate, calcium carbonate and sucroferric oxyhydroxide, 67 mg of each, were used. The experiments were performed in duplicate. The primary outcome was the difference in the amount of bound phosphate for each binder after 6 h in solutions at two different pH values. Secondary outcomes were the influence of phosphate concentration on phosphate binding, next to binding patterns and phosphate binder saturation.

RESULTS AND CONCLUSION

In this specific in vitro setting, lanthanum carbonate, sevelamer carbonate, calcium carbonate and sucroferric oxyhydroxide bound more phosphate in the solution with baseline pH of 3.0. Differences however were small except for lanthanum carbonate. Calcium acetate/magnesium carbonate was most effective in a solution with baseline pH of 6.0. All phosphate binders bound more phosphate in solutions with higher concentrations of phosphate. Sevelamer carbonate, calcium acetate/magnesium carbonate and sucroferric oxyhydroxide bound most phosphate in the first hour and reached maximum binding capacity in less than 6 h.