Effect of histamine H2-receptor antagonist on the phosphorus-binding abilities of calcium carbonate and calcium lactate in hemodialysis patients

Iron absorption and phosphate-lowering effects of ferric citrate hydrate are not influenced by gastric acid secretion inhibitors in patients with chronic kidney disease: a retrospective post hoc analysis

BACKGROUND

Ferric citrate hydrate (FC), an oral iron product is approved as iron preparation for iron deficiency anemia and phosphate binder for chronic kidney disease (CKD). We investigated whether gastric acid secretion inhibitors (GASI) influenced on iron absorption and phosphate-lowering effects of FC.

METHODS

Two phase 3 studies of FC for treatment of hyperphosphatemia in CKD patients (non-dialysis-dependent, 12 weeks, and hemodialysis, 52 weeks), were retrospectively analyzed. Patients were divided into with or without concomitant GASI and levels of iron- and phosphate-related parameters were analyzed.

RESULTS

In non-dialysis study (FC, 60 patients; placebo, 30 patients), 14 FC patients and 14 placebo patients used GASI. No significant differences were found between the FC and placebo groups for adjusted mean differences (95% CI) of changes from baseline to end of treatment (EOT) in serum ferritin [104.84 ng/mL (35.97, 173.71) with GASI vs 145.30 ng/mL (96.34, 194.25) without GASI, P = 0.34], and transferrin saturation (TSAT) [12.56% (- 0.83, 25.95) with GASI vs 18.56% (8.15, 28.98) without GASI, P = 0.49]. In hemodialysis study, 95/180 patients used GASI. Mean changes (SD) from baseline to EOT in serum ferritin were 166.32 ng/mL (153.70) with GASI and 155.16 ng/mL (139.47) without GASI, and for TSAT were 16.60% (19.44) with GASI and 16.02% (18.81) without GASI. In both studies, there were no differences in the changes from baseline to EOT in serum phosphate between with and without GASI cohorts.

CONCLUSION

GASI did not influence on the changes in serum ferritin, TSAT and serum phosphate by FC administration.

Proton pump inhibitors may hinder hypophosphatemic effect of lanthanum carbonate, but not of ferric citrate hydrate or sucroferric oxyhydroxide, in hemodialysis patients

Because end-stage renal disease patients undergoing hemodialysis frequently take acid suppressants for the treatment or prevention of gastrointestinal diseases, it is important to clarify the drug-interactions between acid suppressants and phosphate binders on the control of serum phosphate levels. In the present study, we examined whether the phosphate-lowering effects of three phosphate binders, lanthanum carbonate (LC), ferric citrate hydrate (FCH), and sucroferric oxyhydroxide (SFOH), were affected by proton pump inhibitors (PPIs) in maintenance hemodialysis patients. Laboratory data for 71 patients who had been newly prescribed one of the three phosphate binders were examined. LC at a dosage of 500 ± 217 mg/day significantly decreased serum phosphate levels by −18% in the absence of a PPI (n = 9), while a dosage of 700 ± 230 mg/day only decreased it by −3% in the presence of a PPI (n = 10). Thus, the efficacy of LC in reducing serum phosphate levels was significantly hindered by the presence of PPIs. FCH significantly decreased serum phosphate levels by −18% in the absence of a PPI (n = 7, FCH: 571 ± 189 mg/day) and by −17% in the presence of a PPI (n = 20, FCH: 638 ± 151 mg/day). The decrease in serum phosphate levels by SFOH (393 ± 197 mg/day) was −7% in the absence of a PPI (n = 7), and SFOH at a dosage of 556 ± 316 mg/day significantly decreased serum phosphate levels by −13% in the presence of a PPI (n = 18). These results suggest that the phosphate-lowering effect of LC, but not of FCH or SFOH, is diminished in the presence of PPIs in hemodialysis patients.

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

Background

Hyperphosphatemia is one of the common complications in patients undergoing hemodialysis. Although calcium carbonate (CaC) is often used to control serum inorganic phosphorus level in dialysis patients, co-administration of gastric acid reducers (ARs) may interfere with the phosphate binding effect of CaC. We performed a retrospective medical chart review to study whether ARs attenuate the hypophosphatemic effect of CaC in patients undergoing hemodialysis.

Methods

One hundred and eight chronic hemodialysis patients receiving either CaC alone or CaC concomitant with one of the ARs (proton pump inhibitors and histamine H₂-receptor antagonists) were retrieved from the medical charts in Juntendo University Nerima Hospital. The patients were subdivided according to the interval between hemodialysis sessions (interdialysis interval of 48 or 72 h). A multivariate analysis was performed to identify clinical covariates associated with the variability of serum inorganic phosphorus levels. The study protocol was approved by the Institutional Review Board before the study was begun.

Results

Among patients on hemodialysis with a 72-h interdialysis interval, the magnitude of increase in serum inorganic phosphorus concentration in patients receiving CaC and AR was significantly greater than in those receiving CaC alone. While a similar trend was observed among patients with a 48-h interdialysis interval, the difference did not reach a significant level. A multivariate regression analysis revealed that concomitant administration of ARs with CaC and a longer interdialysis interval (72 h) were significantly and independently associated with the magnitude of increase in serum phosphorus concentration between dialysis sessions. No significant differences in albumin-corrected serum calcium concentrations and incidence of pathological fractures were observed between patients receiving CaC alone and those receiving CaC with ARs.

Conclusions

Concomitant use of ARs with CaC may attenuate the hypophosphatemic effect of CaC in patients undergoing chronic hemodialysis. When hemodialysis patients require prescription of ARs for the prevention of upper gastrointestinal mucosal diseases (such as peptic ulcer), it may be prudent to choose a phosphate binder other than CaC.

A Japanese approach for CKD-MBD

Disturbances in mineral and bone metabolism have a critical role in the pathogenesis of cardiovascular complications in patients with chronic kidney disease (CKD). The term ‘renal osteodystrophy' has recently been replaced by ‘CKD-mineral and bone disorder (CKD-MBD)', which includes abnormalities in bone and mineral metabolism and vascular calcification. The Japanese Society for Dialysis Therapy clinical practice guideline for the management of secondary hyperparathyroidism in chronic dialysis patients was originally published in Japanese in 2006, then in English in 2008. During the past 5 years, this first guideline has contributed to a considerably better understanding and control of secondary hyperparathyroidism in CKD patients by physicians, other medical professionals, and the patients themselves. However, since its publication several new therapeutic modalities have become available for Japanese dialysis patients, which added more evidence to this area. Thus, we revised the guideline to include several new policies, and the new guideline was published in Japanese in 2012. This article contains the new guideline text, and clinical significance of CKD-MBD in Japan.

Calcium-enriched bread for treatment of uremic hyperphosphatemia

OBJECTIVE

To assess phosphate-binding efficacy of a new food product, bread with unusually high calcium content (Ca-bread).

DESIGN AND SETTING

A randomized parallel group trial in the university hospital outpatient dialysis unit.

PATIENTS

Fifty-three randomly selected uremic patients who met the following inclusion criteria: (1) required maintenance hemodialysis treatment, (2) were not to receive vitamin D throughout the study, (3) were nondiabetic, and (4) were diagnosed with hyperphosphatemia.

INTERVENTION

Fifty-three patients were randomized into 2 groups: control group (n = 26), which received calcium acetate as a phosphate binder throughout the study, and Ca-bread group (n = 27), which, after a 2-week washout period, received Ca-bread containing 2.5% of elemental calcium (by weight), which served as a phosphate binder. Bread was made using wheat flour, calcium carbonate, and fermented buttermilk. The amount of elemental calcium used as a phosphate binder was similar in both groups. Observation of both groups lasted 14 weeks.

RESULTS

Mean serum phosphate concentration at randomization was 2.11 +/- 0.14 mmol/L in the control group and 2.20 +/- 0.13 mmol/L in the Ca-bread group. Mean serum calcium concentration at randomization was 2.12 +/- 0.21 mmol/L in the control group and 2.14 +/- 0.11 mmol/L in the Ca-bread group. The Ca-bread group patients' predialysis phosphate concentration decreased to a mean of 1.67 +/- 0.18 mmol/L (P <.05), and their mean calcium concentration increased to 2.27 +/- 0.11 mmol/L (P = NS). In the control group, neither value changed significantly from the original readings. After the hemodialysis session, the mean serum calcium concentration in the control group and the Ca-bread group increased by 7.5% and 7.9%, respectively (P = NS). Mean phosphate concentration simultaneously decreased to nearly 1/2 its original predialysis value in both groups. Ca-bread group patients saw a decrease in the mean phosphate concentration (from predialysis to postdialysis values) that was 13.8% greater than that of the control group (P = NS).

CONCLUSION

A new form of calcium-containing phosphate binder was developed: Ca-bread with an elemental calcium content of 2.5%. Ca-bread allows for effective amelioration of hyperphosphatemia without inducing hypercalcemia. Furthermore, patient compliance may increase if hyperphosphatemia can be treated by consuming bread with an elevated calcium content.