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Phosphate Binders (phosphate + binder)
Selected AbstractsEffect of Iron(III) Chitosan Intake on the Reduction of Serum Phosphorus in RatsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2000JOSEPH BAXTER Because of the widespread use of aluminium- and calcium-containing phosphate binders for the control of hyperphosphataemia in patients with end-stage renal failure, an iron(III) chitosan complex was synthesised and fed to rats to measure its effect on serum phosphorus and calcium, intestinal phosphate binding and phosphate absorption. Thirty-six Wistar rats were randomly selected and distributed into a baseline group (n = 6), a control group (n = 8 (days 0,15), n = 8 (days 16,30)) and a treatment group (n = 8 (days 0,15), n = 8 (days 16,30)). The control groups ingested AIN-76 diet mix with a 1% w/w fibre content; however, the treatment groups had the fibre content completely substituted with iron(III) chitosan. The mean weights of the treated rats were slightly lower from 15 days (not significant); but overall, rat growth was not stunted in the treatment groups. The serum phosphorus levels of the treated group (n = 8) were significantly reduced after 15 days (P = 0.004; control: 5.7 ± 0.9 mg dL,1; treatment: 4.4±0.5 mg dL,1; 95% CI of difference: 0.5,2.2) and 30 days (P = 0.002; control: 5.5 ± 0.9 mg dL,1; treatment = 4.1 ± 0.6 mg dL,1; 95% CI of difference: 0.6,2.3) as compared with the respective control group. The serum calcium-phosphorus product was 62.0 ± 12.1 mg2 dL,2 for the control and 45.1 ± 6.6 mg2 dL,2 for the treatment group after 30 days (P = 0.004). The serum iron concentration of the treatment group did not differ from the baseline value after 15 and 30 days, but the treatment group was significantly higher than the control group (P < 0.05) after 30 days. The faeces phosphorus levels (mg day,1) were higher (P < 0.01) and its iron content was much higher (P < 0.01) for the treated group. The urine phosphorus (mg kg,1) was not significantly reduced for the treated group, but the mean was consistently less. The kidney and liver weights of both groups were similar, but the phosphorus content of the kidney (mg (g kidney),1) was higher for the treated group after 30 days (P = 0.041; control, 4.2 ± 1.2 mg g,1 vs treatment, 5.6 ± 1.4 mg g,1. Because iron(III) chitosan had a high phosphorus-binding capacity of 308 (mg P) per gram of Fe3+ for both the in-vitro (pH 7.5) and in-vivo studies, which is greater than nearly all commonly used phosphate binders, and a small net phosphorus absorption difference of 3.7 mg day,1, it is an efficient phosphate binder for lowering serum phosphate levels without increasing serum calcium levels. [source] Trace Metals' Abnormalities in Hemodialysis Patients: Relationship with MedicationsARTIFICIAL ORGANS, Issue 11 2000Su-Hui Lee Abstract: A multicenter collaborative study was performed to investigate the prevalence of abnormal blood contents of 6 trace metals, copper (Cu), zinc (Zn), aluminum (Al), lead (Pb), cadmium (Cd), and mercury (Hg), in hemodialysis (HD) patients and to analyze their relationship with the medications, such as CaCO3, Ca acetate, Al containing phosphate-binding agents, 1,25-dihydroxy vitD3, 1-hydroxy vitD3, and erythropoietin (EPO), as well as hematocrit level, by chi-square statistics. From 6 medical centers in Taiwan, we included 456 patients in maintenance HD for more than 4 months for this study, and they had continued the previously mentioned medications for at least 3 months. Blood samples were collected before initiating HD, and atomic absorption spectrophotometry was used to measure plasma levels of Cu, Zn, and Al as well as whole blood levels of Pb, Cd, and Hg. Three hundred seventy-five (78%) of the HD patients had low plasma Zn levels, that is, <800 ,g/L, and the mean (±SD) concentration was 705.8 (±128.23) ,g/L in all subjects. One hundred forty-one (31%) of the HD patients had high plasma Al, that is, >50 ,g/L, and the mean (±SD) was 44.30 (±28.28) ,g/L in all subjects. Three hundred thirty-three (73%) of the dialysis patients had high Cd levels, that is, >2.5 ,g/L, and the mean (±SD) was 3.32 (±1.49) ,g/L in all subjects. The majority of HD patients had normal blood levels of Cu, PB, and Hg. Only 21 (4.6%), 5 (1.1%), and 3 (0.06%) patients had elevated blood levels of Cu, Pb, and Hg, respectively. Their mean (±SD) blood concentration of Cu, Pb, and Hg were 1,049.78 (±233.25) ,g/L, 7.45 (±3.95) ,g/dL, and 3.17 (±25.56) ,g/L, respectively. Three patients had elevated plasma Hg concentrations, that is, 546, 12.6, and 24.0 ,g/L, respectively. In the 152 normal healthy age and sex matched control group, the blood levels of Al, Cd, and Pb were all significantly lower than the HD patients. However, the levels of Cu and Zn were higher in the control group. The Hg level was not significantly different in both groups. There was no statistical difference between patients with normal and abnormal blood levels of trace metals in various medications except Al containing phosphate binder. The Al containing phosphate binder users had significantly higher plasma Al levels (54.71 ± 26.70 versus 41.15 ± 28.03 ,g/L, p < 0.001) and hematocrit levels (29.61 ± 4.61 versus 27.81 ± 3.91, p < 0.0005). There was no statistical correlation between erythropoietin (EPO) dose and hematocrit level in these patients. In conclusion, the blood level of trace metals of these HD patients except Al was not related to their medications. However, caution must be exercised in interpreting this result as dose and duration of medication; efficiency of HD and water treatment may play an important role. Otherwise, environmental factors, diet, and the aging process may contribute to the trace metal burden in uremia. Thus, Zn and Cu are abundant in seafood, and Cd is abundant in contaminated plants such as rice. [source] Comparison between different dialysate calcium concentrations in nocturnal hemodialysisHEMODIALYSIS INTERNATIONAL, Issue 2 2007Nigel D. TOUSSAINT Abstract Benefits of dialysate with greater calcium (Ca) concentration are reported in nocturnal hemodialysis (NHD) to prevent Ca depletion and subsequent hyperparathyroidism. Studies with patients dialyzing against 1.25 mmol/L Ca baths demonstrate increases in alkaline phosphatase (ALP) and parathyroid hormone (PTH) and increasing dialysate Ca subsequently corrects this problem. However, whether 1.5 or 1.75 mmol/L dialysate Ca is most appropriate for NHD is yet to be determined, and differences in the effect on mineral metabolism of daily vs. alternate daily NHD have also not been well defined. We retrospectively analyzed mineral metabolism in 48 patients, from 2 institutions (30 at Monash and 18 at Geelong), undergoing home NHD (8 hr/night, 3.5,6 nights/week) for a minimum of 6 months. Thirty-seven patients were dialyzed against 1.5 mmol/L Ca bath and 11 patients against 1.75 mmol/L. We divided patients into 4 groups, based on dialysate Ca and also on the hours per week of dialysis, <40 (1.5 mmol/L, n=29 and 1.75 mmol/L, n=8) or ,40 (n=4 and 7). We compared predialysis and postdialysis serum markers, time-averaged over a 6-month period, and the administration of calcitriol and Ca-based phosphate binders between 1.5 and 1.75 mmol/L Ca dialysate groups. Baseline characteristics between all groups were similar, with a slightly longer, but nonsignificant, duration of NHD in both 1.75 mmol/L dialysate groups compared with 1.5 mmol/L. The mean predialysis Ca, phosphate, and Ca × P were similar between the 1.5 and 1.75 mmol/L groups, regardless of NHD hr/week. Postdialysis Ca was significantly greater, with 1.75 vs. 1.5 mmol/L in those dialyzing <40 hr/week (2.64±0.19 vs. 2.50±0.12 mmol/L, p=0.046), but postdialysis Ca × P were similar (2.25±0.44 vs. 2.16±0.29 mmol2/L2, p=0.60). Parathyroid hormone was also lower with 1.75 vs. 1.5 mmol/L baths in the <40 hr/week groups (31.99±26.99 vs. 14.47±16.36 pmol/L, p=0.03), although this difference was not seen in those undertaking NHD ,40 hr/week. Hemoglobin, ALP, and albumin were all similar between groups. There was also no difference in vitamin D requirement when using 1.75 mmol/L compared with the 1.5 mmol/L dialysate. Multivariate analysis to determine independent predictors of postdialysis serum Ca showed a statistically significant positive association with predialysis Ca, dialysate Ca, and total NHD hr/week. An elevated dialysate Ca concentration is required in NHD to prevent osteopenia but differences in serum markers of mineral metabolism between 1.5 and 1.75 mmol/L Ca dialysate in NHD in our study were few. This was similar for patients undertaking NHD <40 or ,40hr/week, although differences in the frequency of NHD may also be as important as dialysate Ca with regard to serum Ca levels. With concerns that prolonged higher Ca levels contribute to increased cardiovascular mortality, the optimal Ca dialysate bath is still unknown and further studies addressing bone metabolism with larger NHD numbers are required. [source] Nocturnal Hemodialysis Is Better Than Quotidian HemodialysisHEMODIALYSIS INTERNATIONAL, Issue 1 2003MP Kooistra Background. It is unknown whether long nocturnal (6,7 times weekly 6,8 hours) hemodialysis (NHD) is better than frequent short hemodialysis (,daily', quotidian hemodialysis, QHD). Methods. A Dutch NHD pilot study (,Nocturne') started in December 2001. We can now evaluate effects of 4 months NHD in 14 patients. Baseline dialysis frequency was 3.5 or less (3.13 ± 0.23, M ± SD) in group A (n = 8), and 4 or more (5.0 ± 0.89) in group B (n = 6), weekly dialysis time was equal in both groups. Results. Single pool Kt/V, being higher in group B at baseline, increased in both groups (A: 3.1 ± 0.8/week to 9.5 ± 2.3, B: 3.8 ± 1.0 to 10.9 ± 4.1). Baseline nPCR, being higher in group B, increased in both groups (A: 1.0 ± 0.3 g/kg/week to 1.4 ± 0.3, and B: 1.2 ± 0.5 to 1.8 ± 0.5). Baseline albumin was higher in group B, and increased in group A (39.6 ± 3.7 g/l to 43.2 ± 1.5), not in B (41.4 ± 2.3 to 42.8 ± 2.3). Target weight increased only in group A (71.8 ± 10.5 kg to 75.3 ± 11.9), not in B (71.4 ± 25.5 to 71.3 ± 26.7). NHD resulted in normophosphatemia in both groups despite phosphate supplementation and cessation of phosphate binders. PTH decreased in both groups (A: 40.6 ± 38.0 pmol/l to 14.4 ± 11.7, B: 35.6 ± 37.7 to 22.4 ± 41.5). In both groups, pre- and postdialysis mean arterial pressure decreased (A: 106.8 ± 7.9 mmHg to 94.4 ± 12.1 and 97.3 ± 9.5 mmHg to 86.3 ± 8.2, B: 102.2 ± 28.4 to 89.4 ± 9.5 and 90.3 ± 26.8 to 82.7 ± 12.9). Antihypertensives were discontinued or markedly reduced. Fatigue, insomnia, prurigo, restlessness, appetite, physical condition, working ability and quality of life (SF36) improved significantly in both groups. Conclusion. This small pilot study suggests that phosphate and PTH control, blood pressure, uremic symptoms and quality of life improve when conventional hemodialysis or QHD patients switch to NHD. Nutritional parameters improve only in the previously conventionally treated group. [source] Effect of Iron(III) Chitosan Intake on the Reduction of Serum Phosphorus in RatsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2000JOSEPH BAXTER Because of the widespread use of aluminium- and calcium-containing phosphate binders for the control of hyperphosphataemia in patients with end-stage renal failure, an iron(III) chitosan complex was synthesised and fed to rats to measure its effect on serum phosphorus and calcium, intestinal phosphate binding and phosphate absorption. Thirty-six Wistar rats were randomly selected and distributed into a baseline group (n = 6), a control group (n = 8 (days 0,15), n = 8 (days 16,30)) and a treatment group (n = 8 (days 0,15), n = 8 (days 16,30)). The control groups ingested AIN-76 diet mix with a 1% w/w fibre content; however, the treatment groups had the fibre content completely substituted with iron(III) chitosan. The mean weights of the treated rats were slightly lower from 15 days (not significant); but overall, rat growth was not stunted in the treatment groups. The serum phosphorus levels of the treated group (n = 8) were significantly reduced after 15 days (P = 0.004; control: 5.7 ± 0.9 mg dL,1; treatment: 4.4±0.5 mg dL,1; 95% CI of difference: 0.5,2.2) and 30 days (P = 0.002; control: 5.5 ± 0.9 mg dL,1; treatment = 4.1 ± 0.6 mg dL,1; 95% CI of difference: 0.6,2.3) as compared with the respective control group. The serum calcium-phosphorus product was 62.0 ± 12.1 mg2 dL,2 for the control and 45.1 ± 6.6 mg2 dL,2 for the treatment group after 30 days (P = 0.004). The serum iron concentration of the treatment group did not differ from the baseline value after 15 and 30 days, but the treatment group was significantly higher than the control group (P < 0.05) after 30 days. The faeces phosphorus levels (mg day,1) were higher (P < 0.01) and its iron content was much higher (P < 0.01) for the treated group. The urine phosphorus (mg kg,1) was not significantly reduced for the treated group, but the mean was consistently less. The kidney and liver weights of both groups were similar, but the phosphorus content of the kidney (mg (g kidney),1) was higher for the treated group after 30 days (P = 0.041; control, 4.2 ± 1.2 mg g,1 vs treatment, 5.6 ± 1.4 mg g,1. Because iron(III) chitosan had a high phosphorus-binding capacity of 308 (mg P) per gram of Fe3+ for both the in-vitro (pH 7.5) and in-vivo studies, which is greater than nearly all commonly used phosphate binders, and a small net phosphorus absorption difference of 3.7 mg day,1, it is an efficient phosphate binder for lowering serum phosphate levels without increasing serum calcium levels. [source] ORAL PHOSPHATE BINDERS FOR THE MANAGEMENT OF SERUM PHOSPHATE LEVELS IN DIALYSIS PATIENTSJOURNAL OF RENAL CARE, Issue 2009Ismail Mohammed MBBS, MRCP SUMMARY Hyperphosphataemia is an inevitable consequence of end stage chronic kidney disease and is present in the majority of dialysis patients. Hyperphosphataemia is statistically associated with increased cardiovascular mortality among dialysis patients. Dietary restriction of phosphate and current dialysis modalities are not sufficiently effective to maintain serum phosphate levels within the recommended range so that the majority of dialysis patients require oral phosphate binders. However, benefits of achieving the recommended range have yet to be demonstrated prospectively. Unfortunately, conventional phosphate binders are not reliably effective and are associated with a range of limitations and side effects. Aluminium containing agents are highly efficient but no longer widely used because of well-established and proven toxicity. Calcium-based salts are inexpensive, effective and most widely used but there is now concern about their association with hypercalcaemia and vascular calcification. Sevelamer hydrochloride and lanthanum carbonate are non-aluminium, calcium-free phosphate binders. They are effective and reasonably well tolerated, but still do not control phosphate levels in all patients. Patient education programmes have been shown to be a useful and effective method of improving achievement of serum phosphate targets. [source] Hydrogen-Bonding Cooperativity: Using an Intramolecular Hydrogen Bond To Design a Carbohydrate Derivative with a Cooperative Hydrogen-Bond Donor CentreCHEMISTRY - A EUROPEAN JOURNAL, Issue 17 2004Virginie Vicente Dr. Abstract Neighbouring groups can be strategically located to polarise HO,,,OH intramolecular hydrogen bonds in an intended direction. A group with a unique hydrogen-bond donor or acceptor character, located at hydrogen-bonding distance to a particular OH group, has been used to initiate the hydrogen-bond network and to polarise a HO,,,OH hydrogen bond in a predicted direction. This enhanced the donor character of a particular OH group and made it a cooperative hydrogen-bond centre. We have proved that a five-membered-ring intramolecular hydrogen bond established between an amide NH group and a hydroxy group (1,2-e,a), which is additionally located in a 1,3 -cis- diaxial relationship to a second hydroxy group, can be used to select a unique direction on the six-membered-ring intramolecular hydrogen bond between the two axial OH groups, so that one of them behaves as an efficient cooperative donor. Talose derivative 3 was designed and synthesised to prove this hydrogen-bonding network by NMR spectroscopy, and the mannopyranoside derivatives 1 and 2 were used as models to demonstrate the presence in solution of the 1,2-(e,a)/five-membered-ring intramolecular hydrogen bond. Once a well-defined hydrogen-bond is formed between the OH and the amido groups of a pyranose ring, these hydrogen-bonding groups no longer act as independent hydrogen-bonding centres, but as hydrogen-bonding arrays. This introduces a new perspective on the properties of carbohydrate OH groups and it is important for the de novo design of molecular recognition processes, at least in nonpolar media. Carbohydrates 1,3 have shown to be efficient phosphate binders in nonpolar solvents owing to the presence of cooperative hydroxy centres in the molecule. [source] |