Pill burden, adherence, hyperphosphatemia, and quality of life in maintenance dialysis patients

Advances in pharmacotherapy for hyperphosphatemia in renal disease

INTRODUCTION

Hyperphosphatemia in chronic kidney disease (CKD) is considered as an independent risk factor for surrogate clinical end points like vascular calcification (VC) and bone disease, or hard clinical outcomes like cardiovascular events. Various treatment options are available for phosphate removal or reduction. Calcium-based phosphate binders (CBB) with their possible positive calcium balance became culprits for progressive VC and increased mortality risk. Non-calcium-based binders (NCBB) treatment allowed a comparable control of hyperphosphatemia with a lower risk of hypercalcemia and a slower progression of VC. Recent data have shown a 22% risk reduction in all-cause mortality with NCBB compared to CBB treatment. The appropriate timing of phosphate binder initiation in CKD patients is still unclear. Recent reports in patients with CKD stages 3b-4 showed increased VC progression when actively treated compared to placebo and a positive calcium, but no negative phosphate balance.

AREAS COVERED

This review discusses the advantages and disadvantages of the pharmacological options to treat hyperphosphatemia.

EXPERT OPINION

The use of phosphate binders is essential in preventing morbidity and mortality in dialysis patients. The choice of phosphate binder takes into account CKD stage, the presence of other components of CKD-mineral and bone disorders, concomitant therapies and drug side-effect profile.

Predictors of quality of life in patients with end-stage renal disease on hemodialysis

Background

Assessment of quality of life (QOL) of end-stage renal disease (ESRD) patients (physical, mental, and social well-being) has become an essential tool to develop better plans of care. Objective of this study is to determine which demographic and biochemical parameters correlate with the QOL scores in patients with ESRD on hemodialysis (HD) using Kidney Disease QOL-36 surveys (KDQOL).

Methods

A retrospective chart review of all ESRD patients who underwent HD at an outpatient center. The five components of the KDQOL were the primary end points of this study (burden of kidney disease, symptoms and problems, effects of kidney disease on daily life, mental component survey, and physical component survey). Scores were grouped into three categories (below average, average, and above average). In addition to demographics (age, sex, and race), the independent variables such as weight gain, number of years on dialysis, urea reduction ratio, calcium, phosphorus, parathyroid hormone, albumin, and hemoglobin in the serum were collected. Chi-square analysis for dependent variables and the nominal independent variables was used, and analysis of variance analysis was used for continuous independent variables. Ordinal regression using PLUM (polytomous universal model) method was used to weigh out possible effects of confounders.

Results

The cohort size was 111 patients. Mean age was 61.8 (±15.5) years; there were more males than females (64.9% vs 35.1%), the mean time-on-dialysis at the time of the study was 4.3 (4.8) years. Approximately two-thirds of the responses on all five domains of the questionnaire ranked average when compared to the national numbers. The remainders were split between above average (20.6%) and below average (13.4%). In our cohort, no relationships were statistically significant between the five dependent variables of interest and the independent variables by chi-square- and t-test analyses. This was further confirmed by regression analysis. Of note, sex carried the strongest statistical significance (with a P-value of 0.16) as a predictor of “the burden of kidney disease on daily life” in ordinal regression.

Conclusion

Prior studies have shown variables such as serum phosphate level, intradialytic weight gain, and dialysis adequacy are associated with lower KDQOL scores; however, this was not evident in our analysis likely due to smaller sample size. Larger size studies are required to better understand the predictors of QOL in ESRD patients on HD.

Serum Phosphorus Levels, Race, and Socioeconomic Status in Incident Hemodialysis Patients

OBJECTIVE

We sought to examine the relationship between race, socioeconomic status, and serum phosphorus levels in patients with end-stage renal disease incident to hemodialysis (HD) at a large, integrated health-care delivery system in Southern California.

DESIGN

Retrospective cohort study.

SUBJECTS

A total of 5,778 adult patients who initiated HD at our institution between January 1, 2007 and June 30, 2013.

MAIN OUTCOME MEASURES

Unadjusted and adjusted time-averaged serum phosphorus levels and actual phosphorus levels over time. Phosphorus levels were also analyzed by repeated measures as a continuous measure and by phosphorus category. Baseline patient covariates included age, self-reported race, gender, cause of end-stage renal disease, and Charlson comorbidity index scores. Education and income level were estimated using geocoded data.

RESULTS

A total of 68,372 phosphorus levels were available for 4,862 patients. Estimated annual family income fell below $40,001 in 66.1% of African Americans (AAs) and 62.7% of Hispanics compared with 43.5% of Asians and 43.7% of whites, P < .0001. Educational level fell into the highest category for whites (70.8%) compared with AA (44.8%) or Hispanic (30.5%) patients, P < .0001. Adjusted time-averaged phosphorus levels were lower among Hispanics (4.33 mg/dL, 95% confidence interval [CI] 4.27-4.40) compared with Asian (4.54 mg/dL, 95% CI 4.45-4.64, P < .001) and white patients (4.48 mg/dL, 95% CI 4.43-4.54, P < .001) but similar to AA patients. Asian patients experienced a significant increase in phosphorus levels over time (0.11 mg/dL per year, P < .0001). There were no significant effects of race, time, or race by time interactions in the unadjusted and adjusted categorical analyses of phosphorus levels.

CONCLUSIONS

Our findings suggest that serum phosphorus levels are similar among HD patients, irrespective of race or socioeconomic status.

A Study to Inform the Design of a National Multicentre Randomised Controlled Trial to Evaluate If Reducing Serum Phosphate to Normal Levels Improves Clinical Outcomes including Mortality, Cardiovascular Events, Bone Pain, or Fracture in Patients on Dialysis

Background. Retrospective, observational studies link high phosphate with mortality in dialysis patients. This generates research hypotheses but does not establish “cause-and-effect.” A large randomised controlled trial (RCT) of about 3000 patients randomised 50 : 50 to lower or higher phosphate ranges is required to answer the key question: does reducing phosphate levels improve clinical outcomes? Whether such a trial is technically possible is unknown; therefore, a study is necessary to inform the design and conduct of a future, definitive trial. Methodology. Dual centre prospective parallel group study: 100 dialysis patients randomized to lower (phosphate target 0.8 to 1.4 mmol/L) or higher range group (1.8 to 2.4 mmol/L). Non-calcium-containing phosphate binders and questionnaires will be used to achieve target phosphate. Primary endpoint: percentage successfully titrated to required range and percentage maintained in these groups over the maintenance period. Secondary endpoints: consent rate, drop-out rates, and cardiovascular events. Discussion. This study will inform design of a large definitive trial of the effect of phosphate on mortality and cardiovascular events in dialysis patients. If phosphate lowering improves outcomes, we would be reassured of the validity of this clinical practice. If, on the other hand, there is no improvement, a reassessment of resource allocation to therapies proven to improve outcomes will result. Trial Registration Number. This trial is registered with ISRCTN registration number ISRCTN24741445.

Novel iron-containing phosphate binders for treatment of hyperphosphatemia

INTRODUCTION

Hyperphosphatemia is a frequent complication of chronic kidney disease and is associated with increased mortality. Despite side effects, risk of accumulation and high costs, phosphate binders (PBs) have become the crucial cornerstone of therapy. The iron-containing PB sucroferric oxyhydroxide (SO) and ferric citrate hydrate (FCH) have entered the market and other candidates are prior market entry.

AREAS COVERED

A literature search was performed using MEDLINE and EMBASE databases to identify references on iron-containing PB with particular regard to efficacy, safety and potential benefits. Additional hand searches were conducted along with a full-text review of any citation that appeared relevant.

EXPERT OPINION

On the highly competitive market, where the 'ideal' PB is still unknown, novel substances that offer clear benefits over available drugs are desired. Although SO and FCH showed similar efficacy and safety compared to sevelamer, head-to-head studies with lanthanum carbonate are absent. Clinical 1-year data in a limited patient cohort suggested improved adherence for SO and a large randomized controlled trial showed significant reduction in hospitalizations and costs for FCH. Additional large randomized controlled trials have now to prove these possible advantages. Cost-effectiveness in comparison to other PB and the exclusion of significant harms under long-term treatment will determine the future use of both drugs.

Sucroferric oxyhydroxide: a review in hyperphosphataemia in chronic kidney disease patients undergoing dialysis

Sucroferric oxyhydroxide (Velphoro®), an iron-based oral phosphate binder, is available for the control of serum phosphorus levels in patients with chronic kidney disease (CKD) on dialysis. In a pivotal phase III trial, sucroferric oxyhydroxide 1000-3000 mg/day for 24 weeks was noninferior to sevelamer carbonate 4800-14,400 mg/day with regard to lowering serum phosphorus levels. Additionally, sucroferric oxyhydroxide at maintenance dosages was significantly more effective than low dosage sucroferric oxyhydroxide (250 mg/day) with regard to maintaining controlled serum phosphorus levels during weeks 24-27 of treatment. Sucroferric oxyhydroxide had a numerically lower mean daily pill burden and better treatment adherence than sevelamer carbonate. Treatment with sucroferric oxyhydroxide was generally well tolerated over 24 weeks' treatment, with the most frequently reported treatment-emergent adverse events being mild, transient diarrhoea and discoloured faeces. In a 28-week extension study, the efficacy and tolerability profile of sucroferric oxyhydroxide remained similar to sevelamer carbonate for up to 52 weeks. In conclusion, sucroferric oxyhydroxide is a valuable treatment option for hyperphosphataemia in CKD patients on dialysis, providing an effective and generally well tolerated noncalcium-based phosphate binder therapy with a lower pill burden than sevelamer carbonate and the potential for improved treatment adherence.

Understanding barriers to optimal medication management for those requiring long-term dialysis: rationale and design for an observational study, and a quantitative description of study variables and data

Background

Rates of medication non-adherence in dialysis patients are high, and improving adherence is likely to improve outcomes. Few data are available regarding factors associated with medication adherence in dialysis patients, and these data are needed to inform effective intervention strategies.

Methods/design

This is an observational cross-sectional study of a multi-ethnic dialysis cohort from New Zealand, with the main data collection tool being an interviewer-assisted survey. A total of 100 participants were randomly sampled from a single centre, with selection stratified by ethnicity and dialysis modality (facility versus home). The main outcome measure is self-reported medication adherence using the Morisky 8-Item Medication Adherence Scale (MMAS-8). Study data include demographic, clinical, social and psychometric characteristics, the latter being constructs of health literacy, medication knowledge, beliefs about medications, and illness perceptions. Psychometric constructs were assessed through the following survey instruments; health literacy screening questions, the Medication Knowledge Evaluation Tool (Okuyan et al.), the Beliefs about Medication Questionnaire (Horne et al.), the Brief Illness Perception Questionnaire (Broadbent et al.). Using the study data, reliability analysis for internal consistency is satisfactory for the scales evaluating health literacy, medication knowledge, and beliefs about medications, with Chronbach’s α > 0.7 for all. Reliability analysis indicated poor internal consistency for scales relating to illness perceptions. MMAS-8 and all psychometric scores are normally distributed in the study data.

Discussion

This study will provide important information on the factors involved in medication non-adherence in New Zealand dialysis patients. The resulting knowledge will inform long-term initiatives to reduce medication non-adherence in dialysis patients, and help ensure that they are addressing appropriate and evidence based targets for intervention.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0097-2) contains supplementary material, which is available to authorized users.

Managing oral phosphate binder medication expenditures within the Medicare bundled end-stage renal disease prospective payment system: economic implications for large U.S. dialysis organizations

BACKGROUND

From January 2016, payment for oral-only renal medications (including phosphate binders and cinacalcet) was expected to be included in the new Medicare bundled end-stage renal disease (ESRD) prospective payment system (PPS). The implementation of the ESRD PPS has generated concern within the nephrology community because of the potential for inadequate funding and the impact on patient quality of care.

OBJECTIVE

To estimate the potential economic impact of the new Medicare bundled ESRD PPS reimbursement from the perspective of a large dialysis organization in the United States.

METHODS

We developed an interactive budget impact model to evaluate the potential economic implications of Medicare payment changes to large dialysis organizations treating patients with ESRD who are receiving phosphate binders. In this analysis, we focused on the budget impact of the intended 2016 integration of oral renal drugs, specifically oral phosphate binders, into the PPS. We also utilized the model to explore the budgetary impact of a variety of potential shifts in phosphate binder market shares under the bundled PPS from 2013 to 2016.

RESULTS

The base model predicts that phosphate binder costs will increase to $34.48 per dialysis session in 2016, with estimated U.S. total costs for phosphate binders of over $682 million. Based on these estimates, a projected Medicare PPS $33.44 reimbursement rate for coverage of all oral-only renal medications (i.e., phosphate binders and cinacalcet) would be insufficient to cover these costs. A potential renal drugs and services budget shortfall for large dialysis organizations of almost $346 million was projected.

CONCLUSIONS

Our findings suggest that large dialysis organizations will be challenged to manage phosphate binder expenditures within the planned Medicare bundled rate structure. As a result, large dialysis organizations may have to make treatment choices in light of potential inadequate funding, which could have important implications for the quality of care for patients with ESRD.

Phosphate binder pill burden, patient-reported non-adherence, and mineral bone disorder markers: Findings from the DOPPS

Because of multiple comorbidities, hemodialysis (HD) patients are prescribed many oral medications, including phosphate binders (PBs), often resulting in a high "pill burden." Using data from the international Dialysis Outcomes and Practice Patterns Study (DOPPS), we assessed associations between PB pill burden, patient-reported PB non-adherence, and levels of serum phosphorus (SPhos) and parathyroid hormone (PTH) using standard regression analyses. The study included data collected from 5262 HD patients from dialysis units participating in the DOPPS in 12 countries. PB prescription ranged from a mean of 7.4 pills per day in the United States to 3.9 pills per day in France. About half of the patients were prescribed at least 6 PB pills per day, and 13% were prescribed at least 12 PB pills per day. Overall, the proportion of patients who reported skipping PBs at least once in the past month was 45% overall, ranging from 33% in Belgium to 57% in the United States. There was a trend toward greater PB non-adherence and a higher number of prescribed PB pills per day. Non-adherence to PB prescription was associated with high SPhos (>5.5 mg/dL) and PTH (>600 pg/mL). Adherence to PB is a challenge for many HD patients and may be related to the number of PB pills prescribed. Prescription of a simplified PB regimen could improve patient adherence and perhaps improve SPhos and PTH levels.

Management of Polypharmacy in Dialysis Patients

Most patients receiving dialysis have other common chronic conditions in addition to end-stage renal disease, including hypertension, diabetes, cardiovascular disease, and mineral and bone disorder, all of which require long-term medication management. Dialysis patients take an average of 10-12 prescribed and over-the-counter medications from an average of 4.7 prescribers, and an average of 19 pills per day. Thus, reducing polypharmacy is not adequate as a medication therapy goal for these patients. Instead, the dialysis community should focus on ensuring that all patients receive medications that are appropriate, effective, safe and convenient. Barriers to this include a fragmented health care system with inadequate communication between multiple prescribers and pharmacies, and frequent care transitions between ambulatory care sites (dialysis centre, ambulatory primary care practice, ambulatory specialty practice) and the hospital, skilled nursing facility or long-term care facility. Three distinct processes are necessary to prevent and solve the resultant medication-related problems (and reduce polypharmacy). These are medication reconciliation (creating an accurate medication list that reflects all medications the patients is taking and how they are being taken), medication review (evaluating the list for appropriateness, effectiveness, safety and convenience in conjunction with the patient's health status), and ongoing patient-centred medication therapy management (e.g., developing treatment plans centred on each patient's medication-related goals). A team approach including pharmacists as part of the dialysis team with the dialysis facility as the primary medication home is needed.

Long-term effects of the iron-based phosphate binder, sucroferric oxyhydroxide, in dialysis patients

Background

Hyperphosphatemia necessitates the use of phosphate binders in most dialysis patients. Long-term efficacy and tolerability of the iron-based phosphate binder, sucroferric oxyhydroxide (previously known as PA21), was compared with that of sevelamer carbonate (sevelamer) in an open-label Phase III extension study.

Methods

In the initial Phase III study, hemo- or peritoneal dialysis patients with hyperphosphatemia were randomized 2:1 to receive sucroferric oxyhydroxide 1.0−3.0 g/day (2−6 tablets/day; n = 710) or sevelamer 2.4−14.4 g/day (3−18 tablets/day; n = 349) for 24 weeks. Eligible patients could enter the 28-week extension study, continuing the same treatment and dose they were receiving at the end of the initial study.

Results

Overall, 644 patients were available for efficacy analysis (n = 384 sucroferric oxyhydroxide; n = 260 sevelamer). Serum phosphorus concentrations were maintained during the extension study. Mean ± standard deviation (SD) change in serum phosphorus concentrations from extension study baseline to Week 52 end point was 0.02 ± 0.52 mmol/L with sucroferric oxyhydroxide and 0.09 ± 0.58 mmol/L with sevelamer. Mean serum phosphorus concentrations remained within Kidney Disease Outcomes Quality Initiative target range (1.13–1.78 mmol/L) for both treatment groups. Mean (SD) daily tablet number over the 28-week extension study was lower for sucroferric oxyhydroxide (4.0 ± 1.5) versus sevelamer (10.1 ± 6.6). Patient adherence was 86.2% with sucroferric oxyhydroxide versus 76.9% with sevelamer. Mean serum ferritin concentrations increased over the extension study in both treatment groups, but transferrin saturation (TSAT), iron and hemoglobin concentrations were generally stable. Gastrointestinal-related adverse events were similar and occurred early with both treatments, but decreased over time.

Conclusions

The serum phosphorus-lowering effect of sucroferric oxyhydroxide was maintained over 1 year and associated with a lower pill burden, compared with sevelamer. Sucroferric oxyhydroxide was generally well tolerated long-term and there was no evidence of iron accumulation.

The effect of a diet containing 70% protein from plants on mineral metabolism and musculoskeletal health in chronic kidney disease

BACKGROUND

Chronic Kidney Disease (CKD) is associated with alterations in phosphorus excretion, and increases in fibroblast growth factor (FGF23) and parathyroid hormone (PTH). Plant protein-based phytate-bound phosphorus, is less bioavailable than that from animal sources. Our one-week study that was conducted previously showed that a nearly 100% plant protein-based diet benefits mineral metabolism in CKD; however, this diet may not be acceptable to patients. Here we hypothesize that a diet containing 70% protein from plants has similar efficacy and is tolerated by CKD patients.

METHODS

Thirteen subjects with CKD 3-4 received an omnivorous diet containing 70% protein from plants for 4 weeks. The primary outcome was change in 24 h urine phosphorus. Secondary outcomes were changes in serum phosphorus, FGF23, PTH, urine sodium excretion, grip strength and fat free mass. Repeated measures analysis of variance (ANOVA) was used to test differences in parameters over the 4 weeks.

RESULTS

Mean age of subjects was 54.8 years. Median eGFR was 26 (IQR 14.7) ml/min/1.73 m(2). Over the 4-week period, urine phosphorus significantly decreased by 215 ± 232 mg/day (p < 0.001). No significant changes in serum FGF23, phosphorus or PTH were noted. Urine sodium and titratable acid decreased significantly on the diet. Hand grip strength and fat-free mass did not change. There were two hyperkalemia events both 5.8 mEq/l, corrected by food substitutions. No other adverse events were observed.

CONCLUSIONS

A 70% plant protein diet is safe, tolerated, and efficacious in lowering urine phosphorus excretion and may be an alternative to phosphate binders.

Hyperphosphatemia Management in Patients with Chronic Kidney Disease

Hyperphosphatemia in chronic kidney disease (CKD) patients is a potentially life altering condition that can lead to cardiovascular calcification, metabolic bone disease (renal osteodystrophy) and the development of secondary hyperparathyroidism (SHPT). It is also associated with increased prevalence of cardiovascular diseases and mortality rates. To effectively manage hyperphosphatemia in CKD patients it is important to not only consider pharmacological and nonpharmacological treatment options but also to understand the underlying physiologic pathways involved in phosphorus homoeostasis. This review will therefore provide both a background into phosphorus homoeostasis and the management of hyperphosphatemia in CKD patients. In addition, it will cover some of the most important reasons for failure to control hyperphosphatemia with emphasis on the effect of the gastric pH on phosphate binders efficiency.

Iron-based phosphate binders: do they offer advantages over currently available phosphate binders?

Increased cardiovascular morbidity and mortality has been associated with the hyperphosphatemia seen in patients with end-stage chronic kidney disease (CKD). Oral phosphate binders are prescribed in these patients to prevent intestinal absorption of dietary phosphate and reduce serum phosphate. In prospective observational cohorts they have shown to decrease all-cause and cardiovascular mortality risk. Different problems have been associated with currently available phosphate binders as positive calcium balance and impaired outcomes with calcium-based phosphate binders or increased costs with non-calcium-based phosphate binders. Iron-based phosphate binders represent a new class of phosphate binders. Several iron-based phosphate binders have undergone testing in clinical trials. Ferric citrate (JTT-751) and sucroferric oxyhydroxide (PA21) are the two iron-based binders that have passed to the clinical field after being found safe and effective in decreasing serum phosphate. Iron from ferric citrate is partially absorbed compared to sucroferric oxyhydroxide. Ferric citrate usage could result in an important reduction in erythropoiesis-stimulating agent (ESA) and IV iron usage, resulting in significant cost savings. Sucroferric oxyhydroxide was effective in lowering serum phosphorus in dialysis patients with similar efficacy to sevelamer carbonate, but with lower pill burden, and better adherence. Ferric citrate may be more suited for the treatment of chronic hyperphosphatemia in CKD patients requiring iron supplements but its use may have been hampered by potential aluminum overload, as citrate facilitates its absorption; sucroferric oxyhydroxide may be more suited for hyperphosphatemic CKD patients not requiring iron supplementation, with low pill burden.

Serum phosphorus levels and pill burden are inversely associated with adherence in patients on hemodialysis

BACKGROUND

Phosphate binders (PBs) account for about one half of the daily pill burden for US hemodialysis (HD) patients, which may reduce adherence. Adherence can be estimated by the medication possession ratio (MPR), which is defined as the proportion of time a patient had sufficient medication to have taken it as prescribed. Gaps of time between prescription fills lower the patient's MPR. We assessed the association of PB pill burden and adherence (MPR) with phosphorus goal attainment.

METHODS

Using pharmacy management program data, HD patients on PB monotherapy were tracked from first PB fill during 1 January 2007-30 June 2011 for 1 year, or until PB change or censoring. Data were assessed with generalized linear models.

RESULTS

We analyzed 8616 patients. Higher pill burden was associated with lower adherence. Lower adherence tended to be associated with higher mean phosphorus levels and lower percentage of patients with serum phosphorus ≤5.5 mg/dL (P < 0.001). The association between adherence and these clinical outcomes was most pronounced in the lowest and highest pill burden strata (<3, >3-6, >12-15, >15).

CONCLUSIONS

Adherence, as measured by the MPR, was negatively related to higher pill burden and phosphorus levels and positively related to patients in the phosphorus target range. Within pill burden strata, phosphorus increased and patients in the target range generally decreased with decreasing adherence, suggesting that patients prescribed fewer PB pills are less likely to have treatment gaps, and may be more likely to achieve phosphorus targets.

Summary adherence estimates do not portray the true incongruity between drug intake, nurse documentation and physicians' orders

Background

Hemodialysis patients (HD) need to adhere to a complex medication regimen. Because their daily pill burden is one of the highest reported, poor compliance is a major cause of therapeutic failure. The primary aim of this study was to define patterns of medication prescription, intake and documentation among HD patients.

Methods

HD patients treated between 2007 and 2009 and assigned to the largest health service provider in Israel were randomly selected. Drug practices were abstracted from their records and compared to electronic pharmacy data. The discrepancy between drug intake reports and the actual purchase was measured to estimate adherence. Drug purchase, intake report and physician order were plotted in complementing diagrams to appreciate consistency and discrepancy patterns.

Results

The study included full analysis of 75 patients. The mean overall drug adherence was 56.7% (95% CI 53.6-59.9%), varying among drug families and over time. Often, there was a systematic disengagement between the nurses’ documentation and the actual patient purchase. Specifically, we observed either different quantities of medication use, improper documentation of a non-purchased drug, drug purchase without nurse documentation and futile physician attempts to modify prescriptions of unpurchased medication. We found a high rate of physician order turbulence for active vitamin D and calcium.

Conclusions

Drug prescription, documentation and adherence are incongruent and their mismatches are diverse. Summary estimates do not divulge the extent of these disparities. These system-wide communication failures compromise patient care. Strategies to promote system reconciliation and reasonable medication prescription are in need.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2369-15-170) contains supplementary material, which is available to authorized users.

Phosphate balance in ESRD: diet, dialysis and binders against the low evident masked pool

Phosphate metabolism is crucial in the pathophysiology of secondary hyperparathyroidism and vascular calcification. High phosphate levels have been consistently associated with unfavorable outcomes in dialysis patients, but several limitations are still hampering a resolutive definition of the optimal targets of phosphate serum levels to be achieved in this cohort. Nonetheless, hyperphosphatemia is a late marker of phosphate overload in humans. Clinical nephrologists routinely counteract the positive phosphate balance in dialysis patients through nutritional counseling, stronger phosphate removal by dialysis and prescription of phosphate binders. However, the superiority against placebo of phosphate control by diet, dialysis or binders in terms of survival has never been tested in dedicated randomized controlled trials. The present review discusses this conundrum with particular emphasis on the rationale supporting the value of a simultaneous intervention against phosphate overload in dialysis patients via the improvement of dietary intakes, dialysis efficiency and an individualized choice of phosphate binders.

Medication burden in CKD-5D: impact of dialysis modality and setting

BACKGROUND

Medication adherence is thought to be around 50% in the general and dialysis population. Reducing the pill burden (PB) reduces regime complexity and can improve adherence. Increased adherence should lead to improvement in treatment outcomes and patient quality of life. There is currently little published data on PB in CKD-5D across dialysis modalities.

METHODS

This is a retrospective, single renal network study. All in-centre HD (MHD), peritoneal dialysis (PD) and home HD (HHD) patients were identified in the Greater Manchester East sector renal network. Information collected included age, sex, comorbidities, daily PB, dialysis vintage and adequacy. Data were retrieved from a customized renal database, clinic and discharge letters with cross validation from the general practitioner when needed.

RESULTS

Two hundred and thirty-six prevalent dialysis patients were studied. HHD patients had a significantly lower PB (11 ± 7 pills/day) compared with PD and MHD (16 ± 7 pills/day). The HHD patients required fewer BP medications to meet the recommended target. HD setting was the only significant factor for reducing PB. For home therapies (HHD versus PD), weekly Kt/v and serum phosphate were significant factors influencing PB. When comparing all modalities, OR of PB ≥ 15/day for MHD versus HHD was 3.9 and PD versus HHD was 4.9. The influence of HHD is dominant above factors such as comorbidities or clinical variables in reducing PB for MHD. Higher clearances achieved by HHD could explain differences in PB with PD.

CONCLUSION

This is the first comparative study of PB across all dialysis modalities and factors that influence it. The PB advantage in HHD may result in greater adherence and might contribute to the outcome benefit often seen with this modality. Higher clearances achieved by HHD could explain differences in PB with PD but the precise reasons for lower PB remain speculative and deserve further research in larger settings.

Medication beliefs are associated with phosphate binder non-adherence in hyperphosphatemic haemodialysis patients

OBJECTIVES

Patients with end-stage kidney disease receiving haemodialysis (HD) are at risk of cardiovascular disease and bone disorders related to high levels of serum phosphate. We studied the association between medication beliefs and depressive symptoms, with non-adherence to phosphate binding medication in a group of HD patients at risk of complications due to hyperphosphatemia.

DESIGN

Cross-sectional design.

METHODS

Baseline data from 112 patients participating in a randomized controlled trial, evaluating an adherence intervention, are presented. All patients had serum phosphate levels >1.6 mmol/l at baseline. Adherence was measured by (1) serum phosphate and (2) Medication Adherence Report Scales (MARS). Beliefs about Medicines (BMQ) and depressive symptoms (PHQ-9) were also evaluated.

RESULTS

Beliefs about Medicines Questionnaire necessity, but not concerns, beliefs were found to correlate with serum phosphate (r = -.23, p < .05) and self-reported adherence (r = .35, p < .01). In regression models, controlling for demographic, clinical and psychological variables, necessity beliefs explained the variance of serum phosphate (β = -.22, p = .01) and self-reported adherence (β = .30, p ≤ .01). Both BMQ concerns and depressive symptoms were not related to non-adherence.

CONCLUSION

Patients' beliefs about the necessity of their prescribed phosphate binding medications explain variation in non-adherence levels, measured both subjective and objectively. Dialysis patient's medication beliefs are potentially modifiable targets for future interventions.

Health-related quality of life after kidney transplantation: who benefits the most?

The influence of dialysis modalities on HRQoL before and after kidney transplantation (KT) and the role of adherence to medication on HRQoL have not been fully studied. Sixty four dialysis patients who answered the 15D HRQoL survey during dialysis were surveyed again after KT. Adherence and employment were also investigated. The mean 15D score was highest among home hemodialysis patients (HHD) and lowest among in-center hemodialysis patients (icHD). After KT, the mean 15D score improved significantly in 78.6% of peritoneal dialysis patients (PD), 47.6% of HHD, and 53.8% of icHD. Then, mean 15D score remained unchanged in 28.6% of HHD and in 23.1% of icHD patients. A deterioration in the 15D score occurred in 14.3% of PD, 23.1% of icHD, and 23.8% of HHD patients, and this was influenced by the number of pills (P = 0.04). Adherence to medication was the lowest in PD, timing being the most challenging task showing a connection to higher creatinine concentration (never forgot 1.41 mg/dl vs. forgot 2.08 mg/dl P = 0.05). Employed patients had a higher mean 15D score. The icHD and PD patients benefited the most from KT and HHD the least. Low pill burden and employment were linked to a better HRQoL.

Comorbidities and medication burden in patients with chronic obstructive pulmonary disease attending pulmonary rehabilitation

PURPOSE

Chronic obstructive pulmonary disease (COPD) is characterized by concomitant systemic manifestations and comorbidities such as cardiovascular disease. Little data exist on the prevalence of comorbidities and medication burden in people with COPD attending pulmonary rehabilitation (PR) programs in Australia. This study aimed to determine the prevalence of comorbidities and describe the type and number of medications reported in a sample of patients with COPD referred to PR.

METHODS

A retrospective audit was conducted on patients referred to PR over a 1-year period. Data were collected on patient demographics, disease severity, comorbidities, and medications by review of patient notes, physician referral, and self-reported medication use.

RESULTS

Data were available on 70 patients (forced expiratory volume in 1 second = 37.5 [26.0] % predicted). Ninety-six percent of patients had at least 1 comorbidity, and 29% had 5 or more. The most common comorbidities were associated with cardiovascular disease (64% of patients). Almost half of the sample was overweight or obese (49%). Prescription medication use was high, with 57% using between 4 and 7 medications, and 29% using 8 or more.

CONCLUSIONS

Patients with COPD attending PR in Australia have high rates of comorbidity. The number of medications prescribed for these individuals is similar to that seen in other chronic disease states such as chronic heart failure. Pulmonary rehabilitation presents opportunities for clinicians to educate patients on self-management strategies for multiple comorbidities, review medication usage, and discuss strategies aimed at optimizing adherence with medication regimes.

Profiling patient attitudes to phosphate binding medication: a route to personalising treatment and adherence support

OBJECTIVE

Nonadherence to phosphate binding medication (PBM) compromises the efficacy of treatment for chronic kidney disease, but its causes are poorly understood. This study sought to explore patient attitudes towards PBM and to evaluate the utility of the necessity-concerns framework for understanding adherence to PBM.

DESIGN

A sample of 221 dialysis patients currently prescribed PBM were surveyed from eight UK renal units.

MAIN OUTCOME MEASURES

Demographic data and clinical information, alongside the Beliefs about Medicines Questionnaire and the medication adherence report scale were reported.

RESULTS

Low adherence to PBM was predicted by reduced beliefs in personal need for PBM (OR = .34; 95% CI: .14-.83; p < .05), and increased concerns about PBM (OR = 3.17; 95% CI: 1.87-5.37; p < .001). Patients were categorised into attitudinal groups based on their beliefs about PBM and being 'skeptical' of PBM (low necessity beliefs and high concerns) was most associated with low adherence.

CONCLUSION

Strategies to improve adherence to PBM should aim to elicit and address patients' beliefs about their personal need for PBM and their concerns about this medication.

Cost-minimization analysis of lanthanum carbonate versus sevelamer hydrochloride in US patients with end-stage renal disease

PURPOSE

Sevelamer hydrochloride (SH) and lanthanum carbonate (LC) are calcium-free phosphate binders used in the clinical management of hyperphosphatemia in patients with end-stage renal disease (ESRD). The objective of this analysis was to assess the cost-effectiveness of LC monotherapy compared with SH monotherapy in US patients with ESRD in a clinical practice setting.

METHODS

This was a post hoc assessment of phosphate binder costs among US patients with ESRD who converted from SH to LC monotherapy in a previously published, 16-week, Phase IV, real-world study. Calculations of drug costs used both average wholesale price (AWP) and wholesale acquisition cost (WAC).

FINDINGS

There were 953 patients with available baseline SH dose data; 950 also had a recorded LC dose >0 mg at baseline, and 691 had dose data available for both SH at baseline and LC at week 16 (post hoc analysis population). Baseline demographic characteristics were similar in excluded patients and the post hoc analysis population. Mean (SD) serum phosphate levels were 5.91 (1.66) mg/dL at baseline and 5.93 (1.85) mg/dL after conversion to LC monotherapy for 16 weeks. Mean AWP costs were US$35.72 (16.89) per day at baseline and US$24.69 (8.28) per day at week 16, yielding an overall mean cost change (defined as LC cost - SH cost) of -US$11.03 (16.37) per day in favor of LC. The overall mean WAC cost change was -US$9.17 (13.64) per day. Within baseline SH dose subgroups 2400 to 4800, >4800 to 7200, >7200 to 9600, and >9600 mg/d, the mean AWP cost change ranged from US$2.78 (9.26) per day in favor of SH for the 2400- to 4800-mg/d subgroup to -US$33.15 (12.58) per day in favor of LC for the >9600-mg/d subgroup. Mean WAC cost changes showed a similar trend, ranging from US$2.33 (7.72) per day to -US$27.59 (10.48) per day. Linear regression analyses revealed that the inflection SH doses corresponding to a mean cost change of zero were 4905 mg/d (AWP) and 4908 mg/d (WAC). For the 455 (66%) patients in the post hoc analysis population who had baseline SH doses at least as high (≥ 5600 mg/d) as these point estimates, the mean SH:LC tablet ratio was ≥ 3.7, indicating a mean reduction in the tablet burden after conversion to LC of ≥ 73%.

IMPLICATIONS

This real-world assessment of comparative phosphate binder drug costs between SH and LC among US patients with ESRD indicates that average cost savings with LC use increased with increasing SH doses. Conversion to LC from SH ≥ 5600 mg/d reduced drug costs and tablet burden while maintaining serum phosphate levels.

Pharmacokinetic considerations in chronic kidney disease and patients requiring dialysis

INTRODUCTION

Chronic kidney disease (CKD) is the progressive decline in renal function over time. Patients with end-stage renal disease require renal replacement therapy such as hemodialysis to support life. Hemodialysis patients require several medications to treat a variety of comorbid conditions. Polypharmacy accompanied by alterations in the pharmacokinetics of medications places hemodialysis patients at increased risk of drug accumulation and adverse events.

AREAS COVERED

We review alterations in the pharmacokinetics of drugs in hemodialysis patients. The major areas of pharmacokinetics, absorption, distribution, metabolism and excretion, are covered and, where appropriate, differences between dialysis patients and non-dialysis CKD patients are compared. In addition, we review the importance of drug dialyzability and its potential impact on drug efficacy. Finally, we describe important clinical examples demonstrating nonrenal drug clearance is significantly altered in CKD.

EXPERT OPINION

Decreases in renal drug excretion experienced by hemodialysis patients have been known for years. Recent animal and human clinical pharmacokinetic studies have highlighted that nonrenal clearance of drugs is also substantially decreased in CKD. Clinical pharmacokinetic studies are required to determine the optimal dosage of drugs in CKD and hemodialysis patients in order to decrease the incidence of adverse medication events in these patient populations.

Relative safety of peginesatide and epoetin alfa

PURPOSE

Peginesatide, a long-acting erythropoiesis-stimulating agent, was recalled in February 2013 following reports of serious and sometimes fatal hypersensitivity reactions in dialysis patients who received a first dose. We assessed the relative risks of mortality and morbidity in peginesatide-treated and matched epoetin alfa-treated patients.

METHODS

From standardized extracts of paid Medicare claims in 2012 and 2013, we identified dialysis patients treated with peginesatide or epoetin between 1 July 2012 and 28 February 2013. For each peginesatide-treated patient, we identified with propensity score matching two epoetin-treated control patients. Patients were followed for up to 2 days after the first peginesatide dose or the referent epoetin dose for death or hospitalization as a result of cardiovascular morbidity or symptoms (composite event), all-cause hospitalization, and emergency room care.

RESULTS

We identified 15 633 peginesatide-treated patients and 31 266 matched epoetin-treated controls. On the day of dose administration, 19 composite events occurred with peginesatide (incidence, 0.12%) and 14 with epoetin (0.04%); the hazard ratio was 2.7 (95% confidence interval, 1.4-5.4). With follow-up for 1 and 2 subsequent days, hazard ratios were 1.6 (1.0-2.4) and 1.5 (1.1-2.0), respectively. Corresponding hazard ratios were larger among hemodialysis patients with neither intravenous antibiotic nor intravenous iron exposure on the day of dose administration. Hazard ratios for all-cause hospitalization and emergency room care exceeded 1 on and after the day of dose administration.

CONCLUSIONS

Relative to administration of epoetin alfa, first administration of peginesatide in dialysis patients was acutely associated with higher risk of death or hospitalization as a result of cardiovascular morbidity or symptoms.

Medication adherence in Greek hemodialysis patients: the contribution of depression and health cognitions

BACKGROUND

Several studies have shown that non-adherence is a common and increasing problem among individuals with chronic illnesses, including hemodialysis patients.

PURPOSE

The present study aimed to investigate the influence of depression and health cognitions on medication adherence among patients undergoing hemodialysis.

METHOD

A sample of 168 participants was recruited from six general hospitals in the broader area of Athens, consisting of patients undergoing in-center hemodialysis. Measurements were conducted with the following instruments: the Medication Adherence Rating Scale, the Center for Epidemiologic Studies Depression Scale (CES-D), and the Multidimensional Health Locus of Control (MHLC) scale.

RESULTS

The results indicated that medication adherence was associated positively with the dimensions of internal and doctor-attributed health locus of control, measured by the MHLC. It was also related negatively to depression, measured by the CES-D.

CONCLUSIONS

The present study demonstrates the importance of depression in understanding the medication adherence of hemodialysis patients, as well as the contribution of heath cognitions.

VS-501: A NOVEL, NON-ABSORBED, CALCIUM- AND ALUMINUM-FREE, HIGHLY EFFECTIVE PHOSPHATE BINDER DERIVED FROM NATURAL PLANT POLYMER

Inadequate control of serum phosphate in chronic kidney disease can lead to pathologies of clinical importance. Effectiveness of on-market phosphate binders is limited by safety concerns and low compliance due to high pill size/burden and gastrointestinal discomfort. VS-501 is a non-absorbed, calcium- and aluminum-free, chemically-modified, plant-derived polymer. In vitro studies show that VS-501 has a high density and a low swell volume when exposed to simulated gastric fluid (vs. sevelamer). When male Sprague Dawley (SD) rats on normal diet were treated with VS-501 or sevelamer, serum phosphate was not significantly altered, but urinary phosphate levels decreased by >90%. VS-501 had no effect on serum calcium (Ca) or urinary Ca, while 3% sevelamer significantly increased serum and urine Ca. In 5/6 nephrectomized (NX) uremic SD rats on high-phosphate diet, increasing dietary phosphate led to an increase in serum and urine phosphate, which was prevented in rats treated with VS-501 or sevelamer (0.2-5% in food). High phosphate diet also increased serum FGF-23 and parathyroid hormone in 5/6 NX rats, which was prevented by VS-501 or sevelamer. VS-501 or sevelamer increased fecal phosphate in a dose-dependent manner. More aortic calcification was observed in 5/6 NX rats treated with 5% sevelamer, while VS-501 and sevelamer did not show significant effects on cardiac parameters, fibrosis, intestine histology and intestinal sodium-dependent phosphate cotransporter gene expression. These results suggest that VS-501 is effective in binding phosphate with no effects on calcium homeostasis, and may have improved pill burden and gastrointestinal side effects.

Bone mineral metabolism and subsequent hospitalization with poor quality of life in dialysis patients

Background:

Significant impairment in health-related quality of life (HRQOL) among dialysis patients could be partly explained by some co-morbid disorders, such as chronic kidney disease-mineral and bone disorder (CKD-MBD). Also disturbance in calcium and phosphorus metabolism would increase mortality and morbidity. Therefore, further efforts to treat these abnormalities may improve the survival.

Objectives:

We designed a large multicenter population-based study in Iran to describe and assess the relation between HRQOL, hospitalization, and bone metabolism markers.

Patients and Methods:

We enrolled a total of 5820 dialysis patients from 132 dialysis centers in different parts of the country whom were volunteers to cooperate between October 2010 and August 2011. The Iranian adapted version of the Kidney disease quality of life-short form (KDQOL-SF^TM) version 1.3 questionnaire was used to assess the health related quality of life. The clinical and demographic characteristics were gathered from patients’ data files.

Results:

The mean (SD) age of patients was 54.88 (16.36) years, and the range was 2 to 99 years. Of all patients, 43.1% were female. The scores of kidney disease component summary (KDCS), physical component summary, mental component summary, and total quality of life were significantly higher in the lower quartile of corrected serum calcium and higher quartile of serum parathyroid hormone (PTH) levels (P < 0.05). In a regression analysis of multilevel data, while corrected serum calcium level was associated with total KDCS and short form health survey (SF-36) scores after adjusting for other variables, hospitalization was directly correlated with serum phosphorus level and had reverse correlation with dialysis duration and quality of life.

Conclusions:

In the current study, quality of life was correlated with serum calcium level, calcium-phosphate product, and serum PTH level, while hospitalization was correlated only with serum phosphorus level. However, quality of life was inversely correlated with hospitalization.

A phase III study of the efficacy and safety of a novel iron-based phosphate binder in dialysis patients

Efficacy of PA21 (sucroferric oxyhydroxide), a novel calcium-free polynuclear iron(III)-oxyhydroxide phosphate binder, was compared with that of sevelamer carbonate in an open-label, randomized, active-controlled phase III study. Seven hundred and seven hemo- and peritoneal dialysis patients with hyperphosphatemia received PA21 1.0–3.0 g per day and 348 received sevelamer 4.8–14.4 g per day for an 8-week dose titration, followed by 4 weeks without dose change, and then 12 weeks maintenance. Serum phosphorus reductions at week 12 were −0.71 mmol/l (PA21) and −0.79 mmol/l (sevelamer), demonstrating non-inferiority of, on average, three tablets of PA21 vs. eight of sevelamer. Efficacy was maintained to week 24. Non-adherence was 15.1% (PA21) vs. 21.3% (sevelamer). The percentage of patients that reported at least one treatment-emergent adverse event was 83.2% with PA21 and 76.1% with sevelamer. A higher proportion of patients withdrew owing to treatment-emergent adverse events with PA21 (15.7%) vs. sevelamer (6.6%). Mild, transient diarrhea, discolored feces, and hyperphosphatemia were more frequent with PA21; nausea and constipation were more frequent with sevelamer. After 24 weeks, 99 hemodialysis patients on PA21 were re-randomized into a 3-week superiority analysis of PA21 maintenance dose in 50 patients vs. low dose (250 mg per day (ineffective control)) in 49 patients. The PA21 maintenance dose was superior to the low dose in maintaining serum phosphorus control. Thus, PA21 was effective in lowering serum phosphorus in dialysis patients, with similar efficacy to sevelamer carbonate, a lower pill burden, and better adherence.

Hypertension in hemodialysis patients: an opinion-based update

Hypertension is highly prevalent in hemodialysis patients but its management remains a matter of debate. In this review, we discuss the observational studies on the association of blood pressure with outcomes, measurement of blood pressure in hemodialysis patients and present an opinion-based approach to treating hypertension.

MgCaCO3 versus CaCO3 in peritoneal dialysis patients--a cross-over pilot trial

BACKGROUND

Despite adverse effects such as constipation, vascular calcification, and hypercalcemia, calcium-based salts are relatively affordable and effective phosphate binders that remain in widespread use in the dialysis population. We conducted a pilot study examining whether the use of a combined magnesium/calcium-based binder was as effective as calcium carbonate at lowering serum phosphate levels in peritoneal dialysis (PD) patients.

METHODS

This was a cross-over, investigator-masked pilot study in which prevalent PD patients received calcium carbonate alone (200 mg calcium per tablet) or calcium magnesium carbonate (100 mg calcium, 85 mg magnesium per tablet). Primary outcome was serum phosphate level at 3 months. Analysis was as per protocol.

RESULTS

Twenty patients were recruited, 17 completed the study. Mean starting dose was 11.35 ± 7.04 pills per day of MgCaCO3 and 9.00 ± 4.97 pills per day of CaCO3. Mean phosphate levels fell from 2.13 mmol/L to 2.01 mmol/L (95% confidence interval (CI): 1.76 - 2.30, p = 0.361) in the MgCaCO3 group, and 1.81 mmol/L (95% CI: 1.56 - 2.0, p = 0.026) in the CaCO3 alone group. Six (35%) patients taking MgCaCO3 and 9 (54%) taking CaCO3 alone achieved Kidney Disease Outcomes Quality Initiative (KDOQI) serum phosphate targets at 3 months. Diarrhea developed in 9 patients taking MgCaCO3 and 3 taking CaCO3. Serum magnesium exceeded 1.4 mmol/L in 5 patients taking MgCaCO3 while serum calcium exceeded 2.65 mmol/L in 3 patients receiving CaCO3. When compared to the initial dose, the prescribed dose at 3 months was reduced by 44% (to 6.41 tablets/day) in the MgCaCO3 group and by 8% (to 8.24 pills per day) in the CaCO3 alone group.

CONCLUSION

Compared with CaCO3 alone, the preparation and dose of MgCaCO3 used in this pilot study was no better at lowering serum phosphate levels in PD patients, and was associated with more dose-limiting side effects.

Drug adherence in chronic kidney diseases and dialysis

Poor long-term adherence and persistence to drug therapy is universally recognized as one of the major clinical issues in the management of chronic diseases, and patients with renal diseases are also concerned by this important phenomenon. Chronic kidney disease (CKD) patients belong to the group of subjects with one of the highest burdens of daily pill intake with up to >20 pills per day depending on the severity of their disease. The purpose of the present review is to discuss the difficulties encountered by nephrologists in diagnosing and managing poor adherence and persistence in CKD patients including in patients receiving maintenance dialysis. Our review will also attempt to provide some clues and new perspectives on how drug adherence could actually be addressed and possibly improved. Working on drug adherence may look like a long and tedious path, but physicians and healthcare providers should always be aware that drug adherence is in general much lower than what they may think and that there are many ways to improve and support drug adherence and persistence so that renal patients obtain the full benefits of their treatments.

The impact of nurse-led education on haemodialysis patients' phosphate binder medication adherence

BACKGROUND

Phosphate binder medication adherence is required to maintain optimal phosphate levels and minimise bone disease in people with end stage kidney disease.

OBJECTIVES

To examine the impact of a nurse-led education intervention on bone disorder markers, adherence to phosphate binder medication and medication knowledge.

DESIGN

Descriptive study with a paired pre-post intervention survey.

PARTICIPANTS

Adults receiving haemodialysis.

METHODS

Twelve-week intervention where patients self-administered their phosphate binder medication at each dialysis treatment. Nurses provided individualised education. Patients completed a pre- and post-intervention survey designed to explore their knowledge of phosphate binders.

RESULTS

There were no statistically significant changes in clinical markers but a significant improvement in the proportion of patients who took their phosphate binder correctly, increasing from 44 to 72% (p = 0.016). There were moderate to large effect size changes for improved knowledge.

CONCLUSIONS

A nurse-led intervention education programme can increase patients' phosphate binder adherence. However, this does not necessarily manifest into improved serum phosphate levels.

Reasons for phosphate binder discontinuation vary by binder type

OBJECTIVE

Nonadherence to phosphate binder regimen is common among end-stage renal disease patients and contributes to elevated phosphorus levels. Pill burden, side effects, complex regimens, and cost all contribute to nonadherence. We retrospectively analyzed reasons for discontinuation in hemodialysis patients receiving treatment at a large U.S. dialysis organization to better understand the drivers of nonadherence for particular phosphate binders.

DESIGN AND SETTING

Patient electronic medical records were reviewed to identify phosphate binder prescriptions and reasons for discontinuation. Reasons for discontinuation were categorized and the percentage of patients on each type of phosphate binder was calculated within categories.

SUBJECTS

Medicare patients of age ≥18 years, receiving in-center hemodialysis treatment between July 1, 2009, and June 30, 2011, were included in the analysis.

RESULTS

We classified 30,933 patient records with a stated reason for phosphate binder discontinuation for this study. Of these records, 50.1% cited that the patient discontinued the phosphate binder but contained no additional information; "lab results" were cited for 27.4% of the reasons for discontinuation and "patient-reported side effects" for 10.8%. Although patients on lanthanum carbonate accounted for 14% of the total number reasons for discontinuation assessed, they comprised 40% of the "patient-reported side effects" category and were similarly overrepresented in 4 of the 5 subcategories.

CONCLUSIONS

The high percentage of patient-reported side effects resulting in discontinuation identifies an unmet need for improved phosphate binders. A disproportionate percentage of patients prescribed lanthanum carbonate reported side effects, however further work is needed to identify the relative tolerability of phosphate binders and potential explanations.

Managing serum phosphate in haemodialysis patients: time for an innovative approach?

BACKGROUND/OBJECTIVES

Hyperphosphataemia, a common biochemical abnormality in chronic kidney disease, poses significant management challenges. This study aims to determine whether the reasons for this are multifactorial; including poor dietary knowledge, poor adherence to a low phosphate diet and phosphate-binding medications and the impact of age on these parameters.

SUBJECTS/METHODS

In order to compare serum phosphate and other associated parameters to the UK Renal Association Clinical Practice Guidelines 2010 an audit and service evaluation questionnaire was carried out in May 2011 on 130 haemodialysis outpatients attending the Plymouth Dialysis Unit.

RESULTS

Fifty-three percent of patients had serum phosphate within the target range of 1.1-1.7 mmol/l, 77% and 85% had serum calcium and parathyroid hormone within target ranges, respectively. Younger patients (18-45 years) were significantly less likely to have serum phosphate within range χ(2) (2, n=124)=18.77, P<0.001. Despite better knowledge of their own phosphate levels (P=0.005), phosphorus-rich foods (P<0.001), symptoms of hyperphosphataemia (P<0.001) and increased use of Renal Patient View (P=0.002), <65 years old had significantly higher phosphate levels than those >65 years (P<0.001). No significant associations were found between phosphate control and the following factors: gender, timing of dialysis shift, years on dialysis or dialysis adequacy.

CONCLUSIONS

In this population, despite better knowledge, younger patients have worse phosphate control than older patients. Using the same dietary education techniques may not be suitable for all ages, more innovative approaches supported by skilled health professionals are needed to motivate and engage with younger patients to promote self-management and adherence.

The real-world dose-relativity of sevelamer hydrochloride and lanthanum carbonate monotherapy in patients with end-stage renal disease

INTRODUCTION

Sevelamer hydrochloride (SH) and lanthanum carbonate (LC) are calcium-free phosphate binders used for the management of hyperphosphatemia in patients with end-stage renal disease (ESRD). The objective of this analysis was to evaluate the real-world dose-relativity between SH and LC monotherapy in US patients with ESRD.

METHODS

This was a post hoc analysis of a 16-week, real-world study (Vemuri et al. in BMC Nephrol 12:49, 2011) of the efficacy of conversion to LC monotherapy from other phosphate binders. The SH:LC dose-relativity ratio, based on the mean daily dose, was calculated in the subset of patients from the Vemuri study who converted from SH to LC monotherapy and had available SH and LC dose data.

RESULTS

A total of 950 patients converted from SH to LC monotherapy and had recorded dose data. The post hoc analysis population comprised 691 patients with available dose data for both SH at baseline and LC at week 16. The mean (SD) serum phosphate level at baseline was 5.91 (1.66) mg/dL. After conversion to LC monotherapy for 16 weeks, the mean (SD) serum phosphate level was 5.93 (1.85) mg/dL. The mean (SD) daily baseline SH dose was 7,703 (3,642) mg and the mean (SD) daily LC dose at week 16 was 2,800 (939) mg (9.6 versus 2.8 tablets, respectively; P < 0.0001), resulting in a SH:LC dose-relativity ratio of 2.8. The median individual patient SH:LC dose-relativity ratio was 2.6 (95% CI 2.6-2.8). Across baseline SH dose subgroups (2,400-4,800, >4,800-7,200, >7,200-9,600, and >9,600 mg/day), the mean daily SH dose was 4,051, 7,047, 9,253, and 13,150 mg, respectively. In comparison, the mean daily LC dose was 2,445-3,156 mg. Thus, patients requiring baseline SH doses >7,200 mg/day (41% of the analysis population) had higher SH:LC dose-relativity ratios of 3.1-4.2 (median individual patient ratios 3.1-4.0).

CONCLUSION

In this post hoc analysis of real-world dose-relativity, the overall SH:LC dose-relativity ratio was 2.8 (median individual patient ratio 2.6 (95% CI 2.6-2.8). These findings are consistent with the World Health Organization-defined daily dose and previous studies of the relative phosphate binding capacity of the two drugs. Patients requiring SH doses >7,200 mg/day had higher SH:LC dose-relativities of 3.1-4.2 (median individual patient ratios 3.1-4.0). These findings have implications for the tablet burden and cost-effectiveness of SH and LC in the treatment of hyperphosphatemia.

Medication treatment complexity and adherence in children with CKD

BACKGROUND AND OBJECTIVES

The complexity of CKD management in children is increased by the number of comorbid conditions. This study assessed the prevalence of comorbidities in pediatric CKD and the frequency with which multiple comorbidities present together by assessing prevalent medication use by CKD stage and diagnosis and their association with clinical or sociodemographic factors. The association between number and frequency of dosing of medications prescribed and self-report of nonadherence was also assessed.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this cross-sectional analysis of the Chronic Kidney Disease in Children study, medication use at study entry grouped by indication was examined by CKD stage, diagnosis, age, race, ethnicity, income, and CKD duration. Multivariate adjusted predictors of medication use and clustering were examined. Nonadherence was assessed by self-report of missed medications in the past 7 days.

RESULTS

The 558 eligible participants had a median age of 11 years and median GFR of 44 ml/min per 1.73 m(2); 62% of participants were male and 78% had nonglomerular kidney disease. The number of medications for treatment of CKD comorbidities increased with advanced CKD stage (2.5-fold for stages IV versus II; P<0.001) and glomerular disease (1.4-fold versus nonglomerular; P<0.001). Three distinct medication clusters were identified that corresponded to treatment of glomerular disease, advanced renal tubular dysfunction, and proteinuric complications, respectively. Nonadherence was associated with increased medication dosing frequency (administration >2 times/d; P<0.001) but not the number of medications.

CONCLUSIONS

Medical therapy for children with CKD is complex and is affected by glomerular diagnosis, CKD stage, and medication frequency. The need for CKD-related medication treatment cannot be easily predicted by CKD staging alone. Poorer adherence was associated with increased medication frequency, but not with the number of medical problems needing treatment. Consolidating medical treatment and reducing medication frequency may improve adherence rates in children with CKD.

Lanthanum carbonate for the control of hyperphosphatemia in chronic renal failure patients: a new oral powder formulation - safety, efficacy, and patient adherence

Chronic kidney disease (CKD) is associated with very high mortality rates, mainly of cardiovascular origin. The retention of phosphate (P) and increased fibroblast growth factor-23 levels are common, even at early stages of CKD, due to disturbances in normal P homeostasis. Later, hyperphosphatemia appears, which has also been strongly associated with high mortality rates linked to P-mediated cardiovascular and procalcifying effects. Treatment guidelines for these patients continue to be poorly implemented, at least partially due to the lack of adherence to a P-restricted diet and P-binder therapy. Calcium-free P binders, such as lanthanum carbonate, have been associated with a decreased progression of vascular calcification, rendering them an important therapeutic alternative for these high cardiovascular risk CKD patients. Lanthanum carbonate has typically been available as chewable tablets, and the new presentation as an oral powder may provide a useful alternative in the therapeutic armamentarium. This powder is a tasteless, odorless, and colorless semisolid compound miscible with food. In a recent study in healthy individuals, the safety and efficacy of this novel form were evaluated, and it was concluded that it is well tolerated and pharmacodynamically equivalent to the chewable form. In the long run, individualization of preferences and treatments seems an achievable goal prior to final demonstration of improvements in hard outcomes in wide clinical trials in CKD patients.

New models of chronic kidney disease care including pharmacists: improving medication reconciliation and medication management

PURPOSE OF REVIEW

Patients with chronic kidney disease (CKD) are complex, have many medication-related problems (MRPs) and high rates of medication nonadherence, and are less adherent to some medications than patients with higher levels of kidney function. Nonadherence in CKD patients increases the odds of uncontrolled hypertension, which can increase the risk of CKD progression. This review discusses reasons for gaps in medication-related care for CKD patients, pharmacy services to reduce these gaps and successful models that incorporate pharmacist care.

RECENT FINDINGS

Pharmacists are currently being trained to deliver patient-centred care, including identification and management of MRPs and helping patients overcome barriers to improve medication adherence. A growing body of evidence indicates that pharmacist services for CKD patients, including medication reconciliation and medication therapy management, positively affect clinical and cost outcomes, including lower rates of decline in glomerular filtration rates, reduced mortality and fewer hospitalizations and hospital days, but more robust research is needed. Team-based models including pharmacists exist today and are being studied in a wide range of innovative care and reimbursement models.

SUMMARY

Opportunities are growing to include pharmacists as integral members of CKD and dialysis healthcare teams to reduce MRPs, increase medication adherence and improve patient outcomes.

Development and cultural adaptation of the Spanish version of the End Stage Renal Disease Adherence Questionnaire (SESRD-AQ)

We previously developed and validated the End-Stage Renal Disease Adherence Questionnaire (ESRD-AQ) to measure adherence behaviors (e.g., hemodialysis attendance, medication use, fluid restrictions, and diet) of patients on maintenance hemodialysis. To determine whether the ESRD-AQ can be used to measure adherence behaviors in non-English-speaking patients, we translated and adapted the ESRD-AQ into Spanish (SESRD-AQ) using forward and backward translation and cultural adaptation of the content. Validity and reliability were measured using item-level content validity indexes, intraclass correlation coefficients, and known-group analysis. All validity indices were within an acceptable range; strong test-retest stability existed across all items, with intraclass correlation coefficients ranging from 0.82 to 1.00. The developed SESRD-AQ is a valid assessment tool for use among Spanish-speaking patients on maintenance hemodialysis. This instrument refinement and validation process can be replicated with other maintenance hemodialysis population groups.