Medication Deprescribing in Patients Receiving Hemodialysis: A Prospective Controlled Quality Improvement Study

Rationale & Objective

Patients treated with dialysis are commonly prescribed multiple medications (polypharmacy), including some potentially inappropriate medications (PIMs). PIMs are associated with an increased risk of medication harm (eg, falls, fractures, hospitalization). Deprescribing is a solution that proposes to stop, reduce, or switch medications to a safer alternative. Although deprescribing pairs well with routine medication reviews, it can be complex and time-consuming. Whether clinical decision support improves the process and increases deprescribing for patients treated with dialysis is unknown. This study aimed to test the efficacy of the clinical decision support software MedSafer at increasing deprescribing for patients treated with dialysis.

Study Design

Prospective controlled quality improvement study with a contemporaneous control.

Setting & Participants

Patients prescribed ≥5 medications in 2 outpatient dialysis units in Montréal, Canada.

Exposures

Patient health data from the electronic medical record were input into the MedSafer web-based portal to generate reports listing candidate PIMs for deprescribing. At the time of a planned biannual medication review (usual care), treating nephrologists in the intervention unit additionally received deprescribing reports, and patients received EMPOWER brochures containing safety information on PIMs they were prescribed. In the control unit, patients received usual care alone.

Analytical Approach

The proportion of patients with ≥1 PIMs deprescribed was compared between the intervention and control units following a planned medication review to determine the effect of using MedSafer. The absolute risk difference with 95% CI and number needed to treat were calculated.

Outcomes

The primary outcome was the proportion of patients with one or more PIMs deprescribed. Secondary outcomes include the reduction in the mean number of prescribed drugs and PIMs from baseline.

Results

In total, 195 patients were included (127, control unit; 68, intervention unit); the mean age was 64.8 ± 15.9 (SD), and 36.9% were women. The proportion of patients with ≥1 PIMs deprescribed in the control unit was 3.1% (4/127) vs 39.7% (27/68) in the intervention unit (absolute risk difference, 36.6%; 95% CI, 24.5%-48.6%; P < 0.0001; number needed to treat = 3).

Limitations

This was a single-center nonrandomized study with a type 1 error risk. Deprescribing durability was not assessed, and the study was not powered to reduce adverse drug events.

Conclusions

Deprescribing clinical decision support and patient EMPOWER brochures provided during medication reviews could be an effective and scalable intervention to address PIMs in the dialysis population. A confirmatory randomized controlled trial is needed.

Electronic Decision Support for Deprescribing in Patients on Hemodialysis: Clinical Research Protocol for a Prospective, Controlled, Quality Improvement Study

Background

Patients on dialysis are commonly prescribed multiple medications (polypharmacy), many of which are potentially inappropriate medications (PIMs). Potentially inappropriate medications are associated with an increased risk of falls, fractures, and hospitalization. MedSafer is an electronic tool that generates individualized, prioritized reports with deprescribing opportunities by cross-referencing patient health data and medications with guidelines for deprescribing.

Objectives

Our primary aim was to increase deprescribing, as compared with usual care (medication reconciliation or MedRec), for outpatients receiving maintenance hemodialysis, through the provision of MedSafer deprescribing opportunity reports to the treating team and patient empowerment deprescribing brochures provided directly to the patients themselves.

Design

This controlled, prospective, quality improvement study with a contemporary control builds on existing policy at the outpatient hemodialysis centers where biannual MedRecs are performed by the treating nephrologist and nursing team.

Setting

The study takes place on 2 of the 3 outpatient hemodialysis units of the McGill University Health Centre in Montreal, Quebec, Canada. The intervention unit is the Lachine Hospital, and the control unit is the Montreal General Hospital.

Patients

A closed cohort of outpatient hemodialysis patients visit one of the hemodialysis centers multiple times per week for their hemodialysis treatment. The initial cohort of the intervention unit includes 85 patients, whereas the control unit has 153 patients. Patients who are transplanted, hospitalized during their scheduled MedRec, or die before or during the MedRec will be excluded from the study.

Measurements

We will compare rates of deprescribing between the control and intervention units following a single MedRec. On the intervention unit, MedRecs will be paired with MedSafer reports (the intervention), and on the control unit, MedRecs will take place without MedSafer reports (usual care). On the intervention unit, patients will also receive deprescribing patient empowerment brochures for select medication classes (gabapentinoids, proton-pump inhibitors, sedative hypnotics and opioids for chronic non-cancer pain). Physicians on the intervention unit will be interviewed post-MedRec to determine implementation barriers and facilitators.

Methods

The primary outcome will be the proportion of patients with 1 or more PIMs deprescribed on the intervention unit, as compared with the control unit, following a biannual MedRec. This study will build on existing policies aimed at optimizing medication therapy in patients undergoing maintenance hemodialysis. The electronic deprescribing decision support tool, MedSafer, will be tested in a dialysis setting, where nephrologists are regularly in contact with patients. MedRecs are an interdisciplinary clinical activity performed biannually on the hemodialysis units (in the Spring and Fall), and within 1 week following discharge from any hospitalization. This study will take place in the Fall of 2022. Semi-structured interviews will be conducted among physicians on the intervention unit to determine barriers and facilitators to implementation of the MedSafer-supplemented MedRec process and analyzed according to grounded theory in qualitative research.

Limitations

Deprescribing can be limited due to nephrologists' time constraints, cognitive impairment of the hemodialyzed patient stemming from their illness and complex medication regimens, and lack of sufficient patient resources to learn about the medications they are taking and their potential harms.

Conclusions

Electronic decision support can facilitate deprescribing for the clinical team by providing a nudge reminder, decreasing the time it takes to review and effectuate guideline recommendations, and by lowering the barrier of when and how to taper. Guidelines for deprescribing in the dialysis population have recently been published and incorporated into the MedSafer software. To our knowledge, this will be the first study to examine the efficacy of pairing these guidelines with MedRecs by leveraging electronic decision support in the outpatient dialysis population.

Trial registration

This study was registered on Clinicaltrials.gov (NCT05585268) on October 2, 2022, prior to the enrolment of the first participant on October 3, 2022. The registration number is pending at the time of protocol submission.

Deprescribing Opportunities for Hospitalized Patients With End-Stage Kidney Disease on Hemodialysis: A Secondary Analysis of the MedSafer Cluster Randomized Controlled Trial

Background

End-stage kidney disease patients on dialysis have a substantial risk of polypharmacy due their propensity for comorbidity and contact with the health care system. MedSafer is an electronic decision support tool that integrates patient comorbidity and medication lists to generate personalized deprescribing reports focused on identifying potentially inappropriate medications (PIMs).

Objective

To conduct a secondary analysis of patients on regular hemodialysis included in the MedSafer randomized controlled trial to investigate the patterns of polypharmacy and evaluate the efficacy of the MedSafer deprescribing algorithms.

Design

Secondary analysis of a cluster randomized clinical trial.

Setting

Medical units in 11 acute care hospitals in Canada.

Patients

The MedSafer trial enrolled 5698 participants with an expected prognosis of >3 months, age 65 years and older, and on 5 or more daily home medications; 140 participants were receiving chronic hemodialysis.

Measurements

The primary outcome of the trial was 30-day adverse drug events (ADEs) post-hospital discharge, and a key secondary outcome was deprescribing.

Methods

Control patients received usual care (medication reconciliation), whereas clinicians caring for intervention patients received a MedSafer report that highlighted individualized opportunities for deprescribing.

Results

There were 70 patients in each of the control and intervention arms. The median number of home medications was 14 (compared with a median of 10 medications in the general trial population). The most frequent medications observed that were potentially inappropriate were proton pump inhibitors (potentially inappropriate in 55/76 users; 72.4%), diabetes medications in patients with a HBA1C <7.5% (36/65 users; 55.4%), docusate (27/27 users; 100%), gabapentinoids (27/36 users; 75%), and combination antiplatelet/anticoagulants (22/97 users; 22.7%). The proportion of PIMs deprescribed was higher during the intervention phase (28.8% vs 19.3%; absolute increase 9.4% [95% confidence interval 1.3%-17.6%]) compared with the control phase. There was no observed difference in ADEs at 30-day post-discharge between the control and the intervention groups. The most common ADE (n = 3) was gastrointestinal bleeding attributed to antiplatelet agents.

Limitations

This was a post hoc exploratory analysis, the original trial did not stratify by hemodialysis status, and the small sample size precludes drawing any definitive conclusions.

Conclusion

MedSafer facilitates deprescribing in hospitalized patients on hemodialysis. Larger-scale implementation of decision support software for deprescribing in dialysis and long-term follow-up are likely required to demonstrate an impact on ADEs.

Thrombotic Microangiopathy in a Pregnant Woman With Kidney Transplantation: A Case Report

BACKGROUND

The differential diagnosis of thrombotic microangiopathy (TMA) in pregnancy includes common conditions, such as preeclampsia. In women with kidney transplantation, additional causes of TMA must be considered.

CASE

A 22-year-old primigravid woman with a transplanted kidney presented with fetal growth restriction, hypertension, acute kidney injury, and hemolysis at 28 weeks gestation. While her clinical presentation was initially consistent with preeclampsia, hemolysis persisted beyond 1 week postpartum. Diagnoses of TMA associated with tacrolimus and antibody-mediated rejection were considered. An elevated tacrolimus level likely contributed to her TMA and a decrease in dosage improved her clinical picture and laboratory markers.

CONCLUSION

We report the case of a pregnant kidney transplant recipient with TMA. A multidisciplinary approach is required to optimize the maternal health outcomes in this complex population.

Primary hyperaldosteronism presenting as persistent postpartum hypertension: Illustrative case and systematic review

We present a case of persistent postpartum hypertension found to be secondary to primary hyperaldosteronism in a woman with a history of recurrent hypertensive disorders of pregnancy and associated fetal complications. Our systematic review revealed only 18 cases of primary aldosteronism diagnosed in women with postpartum hypertension, suggesting that this disorder is under-studied in the postpartum period. A review of these cases suggests that women with primary hyperaldosteronism commonly present with hypertensive disorders of pregnancy, but may only be identified de novo postpartum. However, a high index of suspicion is needed to diagnose primary hyperaldosteronism in the postpartum period, guided by a woman's obstetric history.

Management of chronic kidney disease and dialysis in homeless persons

End-stage renal disease and dialysis are complicated illnesses to manage in homeless persons, who often suffer medical comorbidities, psychiatric disease, cognitive impairment and addictions; descriptions of this population and management strategies are lacking. A retrospective review of dialysis patients who were homeless or unstably housed was undertaken at an urban academic Canadian center from 2001 to 2011. Electronic hospital records were analyzed for demographic, housing, medical, and psychiatric history, dialysis history, adherence to treatment, and outcomes. Two detailed cases of homeless patients with chronic kidney disease are presented. Eleven homeless dialysis patients with a mean age of 52.7±12.3 years, mostly men and mostly from minority groups were dialyzed for 41.1±29.2 months. Most resided permanently in shelters, eventually obtained fistula access, and were adherent to dialysis schedules. Patients were often nonadherent to pre-dialysis management, resulting in emergency starts. Many barriers to care for homeless persons with end-stage kidney disease and on dialysis are identified, and management strategies are highlighted. Adherence is optimized with shelter-based health care and intensive team-oriented case management.

Stage 1 chronic kidney disease in pregnancy

Stage 1 chronic kidney disease (CKD) is defined by normal renal function, an estimated glomerular filtration rate of >90 mL/minute and abnormalities on urinalysis or ultrasound. These patients when pregnant are commonly seen, and diagnoses include diabetic nephropathy, glomerulonephritis, nephrolithiasis, reflux nephropathy, polycystic kidney disease and lupus nephritis. Underlying renal disease may also first become apparent in pregnancy, posing a diagnostic challenge. Patients tend to do well, but all need to be closely monitored particularly for hypertension and pre-eclampsia, which are more common in patients with stage 1 CKD overall. Relevant pregnancy outcomes may be divided into maternal (e.g. renal deterioration, nephrolithiasis, lupus flare, urinary infection or pyelonephritis), fetal (e.g. growth restriction, fetal death or stillbirth) and obstetric (e.g. hypertension, pre-eclampsia, preterm delivery, thrombosis). Specific diagnoses, their clinical features, management strategies and prognosis are reviewed.

Antihypertensive drugs in pregnancy

Blood pressure targets and medications that are safe differ in pregnant women compared with nonpregnant individuals. The principles of treatment for mild, moderate, and severe hypertension in pregnancy, chronic versus gestational versus preeclampsia, and women hypertensive at term versus remote from term are reviewed. The choice of antihypertensive drugs also is discussed; methyldopa, labetalol, and nifedipine, among others, appear safe for use in pregnancy, whereas angiotensin converting enzyme inhibitors and angiotensin receptor blockers should be avoided. The management of increased blood pressure in the postpartum period, and agents to use in lactation, are also discussed.

Pregnancy-associated parvovirus B19 infection causing postinfectious glomerulonephritis

BACKGROUND

Postinfectious glomerulonephritis due to parvovirus B19 during pregnancy is not described in the literature.

OBJECTIVE

A case and renal biopsy of postinfectious glomerulonephritis due to parvovirus B19 during pregnancy is presented.

DISCUSSION AND CONCLUSIONS

The patient contracted "fifth disease," parvovirus B19, in the 10th week of pregnancy, and 2 weeks later developed hypertension, nephrotic range proteinuria, pleural effusions, and evidence of pure red cell aplasia. Serum parvovirus B19 IgM was positive; a renal biopsy was performed, revealing diffuse proliferative glomerulonephritis with immunofluorescent and electron microscopic changes consistent with postinfectious glomerulonephritis. Renal, hemodynamical, and hematological parameters returned to normal by the 16th week gestation, and the pregnancy proceeded without further complication to the mother, with term delivery of a healthy infant.

Management of renal disease in pregnancy

Although renal disease in pregnancy is uncommon, it poses considerable risk to maternal and fetal health. This article discusses renal physiology and assessment of renal function in pregnancy and the effect of pregnancy on renal disease in patients with diabetes, lupus, chronic glomerulonephritis, polycystic kidney disease, and chronic pyelonephritis. Renal diseases occasionally present for the first time in pregnancy, and diagnoses of glomerulonephritis, acute tubular necrosis, hemolytic uremic syndrome, and acute fatty liver of pregnancy are described. Finally, therapy of end-stage renal disease in pregnancy, dialysis, and renal transplantation are reviewed.

Intensifying renal replacement therapy during pregnancy: the role for nocturnal home hemodialysis

Fertility among women receiving conventional hemodialysis or peritoneal dialysis is very low. For those able to conceive it appears that infant survival is poor, and prematurity and its related complications are still commonplace. Nocturnal hemodialysis (NHD) is a form of intensive, self-administered hemodialysis whereby patients receive 3-4 times the duration of conventional hemodialysis resulting in superior removal of uremic toxins compared to traditional dialysis modalities. NHD has been associated with increased fertility, infants with higher birth weights born at more advanced gestational ages, and fewer maternal and fetal complications. These encouraging results suggest a greater role for much more intensive dialysis in pregnancy.

Hypertension in pregnancy

Hypertensive disorders of pregnancy are the most common medical disorders of pregnancy and are associated with increased maternal and perinatal risks. The pathophysiology, diagnosis, and treatment are herein reviewed for chronic hypertension, preeclampsia, gestational hypertension, and severe hypertension. The benefits and risks of treating mild, moderate, and severe hypertension are discussed. A variety of oral and parenteral therapies are approved for the treatment of hypertension in pregnancy; methyldopa, labetalol, and nifedipine have been used safely in pregnancy, as has hydrochlorothiazide in those already taking this medication before conception. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are contraindicated in pregnancy because of adverse fetal effects, and atenolol should be avoided due to concerns with fetal growth. Severe hypertension >160/110 mmHg may require parenteral therapy, and treatment with intravenous labetalol now supplants the use of hydralazine. Women may remain hypertensive for a period postpartum and require treatment for a short interval. Early or severe preeclampsia warrants workup postpartum for secondary causes. Pregnancy induced hypertension or preeclampsia are emerging as risk factors for future cardiovascular risk.

Shelter-based convalescence for homeless adults

OBJECTIVES

Homelessness is associated with increased hospital costs and length of stay, and medical or surgical conditions are typically complicated by secondary diagnoses of substance abuse or mental illness. Convalescence care to provide timely treatment has not been analyzed. This is a retrospective study of diagnoses and utility of shelter-based convalescence in a cohort of homeless subjects.

METHODS

A 20-bed shelter-based unit providing up to 3 months stay post hospital discharge, or for treatment of addictions or for those too ill to remain in the general shelter was studied. Charting was by the use of an electronic health record developed for the project. Demographics, reason for admission and outcomes are retrospectively described.

RESULTS

140 men had 181 admissions from July 2000-April 2003; 23.8% were post hospital discharge, 57.4% were from the general shelter. Average length of stay was 40 days. 83.4% were treated for a medical or surgical condition, 83.6% for psychiatric disease and 29.8% for addictions. Medication adherence was >80% in the majority. During admission, 20% obtained a new health card, 43.6% a new drug card, 89.3% received transportation to appointments, 60% applied for housing and 24.3% obtained housing.

CONCLUSION

A shelter-based convalescence unit can provide health care to homeless persons, treat medical and mental illness, ensure adherence to treatment regimes, decrease substance abuse and assist with housing.

Shelter-based palliative care for the homeless terminally ill

BACKGROUND

The homeless have high rates of mortality, but live in environments not conducive to terminal care. Traditional palliative care hospitals may be reluctant to accept such patients, due to behavior or lifestyle concerns. The Ottawa Inner City Health Project (OICHP) is a pilot study to improve health care delivery to homeless adults. This is a retrospective analysis of a cohort of terminally ill homeless individuals and the effectiveness of shelter-based palliative care. As proof of principle, a cost comparison was performed.

METHODS

28 consecutive homeless terminally ill patients were admitted and died at a shelter-based palliative care hospice. Demographics, diagnoses at admission and course were recorded. Burden of illness was assessed by medical and psychiatric diagnoses, addictions, Karnofsky scale and symptom management. An expert panel was convened to identify alternate care locations. Using standard costing scales, direct versus alternate care costs were compared.

RESULTS

28 patients had a mean age 49 years; average length of stay 120 days. DIAGNOSES: liver disease 43%, HIV/AIDS 25%, malignancy 25% and other 8%. Addiction to drugs or alcohol and mental illness in 82% of patients. Karnofsky performance score mean 40 +/- 16.8. Pain management with continuous opiates in 71%. The majority reunited with family. Compared to alternate care locations, the hospice projected 1.39 million dollars savings for the patients described.

CONCLUSION

The homeless terminally ill have a heavy burden of disease including physical illness, psychiatric conditions and addictions. Shelter-based palliative care can provide effective end-of-life care to terminally ill homeless individuals at potentially substantial cost savings.

Shelter-based managed alcohol administration to chronically homeless people addicted to alcohol

BACKGROUND

People who are homeless and chronically alcoholic have increased health problems, use of emergency services and police contact, with a low likelihood of rehabilitation. Harm reduction is a policy to decrease the adverse consequences of substance use without requiring abstinence. The shelter-based Managed Alcohol Project (MAP) was created to deliver health care to homeless adults with alcoholism and to minimize harm; its effect upon consumption of alcohol and use of crisis services is described as proof of principle.

METHODS

Subjects enrolled in MAP were dispensed alcohol on an hourly basis. Hospital charts were reviewed for all emergency department (ED) visits and admissions during the 3 years before and up to 2 years after program enrollment, and the police database was accessed for all encounters during the same periods. The results of blood tests were analyzed for trends. A questionnaire was administered to MAP participants and staff about alcohol use, health and activities of daily living before and during the program. Direct program costs were also recorded.

RESULTS

Seventeen adults with an average age of 51 years and a mean duration of alcoholism of 35 years were enrolled in MAP for an average of 16 months. Their monthly mean group total of ED visits decreased from 13.5 to 8 (p = 0.004); police encounters, from 18.1 to 8.8 (p = 0.018). Changes in blood test findings were nonsignificant. All program participants reported less alcohol consumption during MAP, and subjects and staff alike reported improved hygiene, compliance with medical care and health.

INTERPRETATION

A managed alcohol program for homeless people with chronic alcoholism can stabilize alcohol intake and significantly decrease ED visits and police encounters.

Antihypertensive therapy in pregnancy

The benefits of antihypertensive therapy in pregnancy remain uncertain. Blood pressure control to prevent or correct severe hypertension can avert maternal target organ damage and may allow obstetricians to prolong pregnancy or avoid hospitalization. Several factors limit the conclusions derived from systematic review of the available studies, including failure to distinguish among women with preeclampsia, gestational hypertension, or whose hypertension antedated pregnancy. As well, the application of consensus guidelines is limited by the unfortunate tendency to measure blood pressure by use of oscillometric devices rather than auscultation. We review the basis for using specific antihypertensive drugs in pregnancy and highlight important shortcomings in therapeutic knowledge that should be addressed in future studies.

NO inhibits Na+-K+-2Cl- cotransport via a cytochrome P-450-dependent pathway in renal epithelial cells (MMDD1)

Nitric oxide (NO) exerts direct effects on nephron transport. We determined the effect of NO on Na(+)-K(+)-2Cl(-) cotransport in a cell line (MMDD1) with properties of macula densa. Na(+)-K(+)-2Cl(-) cotransport was measured as bumetanide-sensitive (86)Rb(+) uptake in the presence of ouabain. MMDD1 cells expressed mRNA for the neuronal isoform of nitric oxide synthase, as well as NKCC1 and NKCC2(B) isoforms of the Na(+)-K(+)-2Cl(-) cotransporter. Preincubation of cells with the NO donors sodium nitroprusside (SNP) or S-nitroso-N-acetylpenicillamine (SNAP) caused concentration-dependent inhibition of Na(+)-K(+)-2Cl(-) cotransport. Both apical and basolateral Na(+)-K(+)-2Cl(-) cotransport was inhibited by NO donors. SNP or SNAP had no significant effect on cellular levels of cGMP, cAMP, cytosolic calcium, or phosphorylation of ERK1 and ERK2. In contrast, the inhibitors of cytochrome P-450, 1-aminobenzotriazole (ABT; 10(-3) M) or ketoconazole (1.5 x 10(-5) M), completely reversed the inhibitory effect of SNAP on apical or basolateral Na(+)-K(+)-2Cl(-) cotransport [apical: control 1.18 +/- 0.15 vs. SNAP (10(-4) M) 0.41 +/- 0.05 pmol x mg(-1) x 5 min(-1); P < 0.001; SNAP (10(-4) M) + ABT 1.32 +/- 0.10 pmol x mg(-1) x 5 min(-1); P = not significant vs. control; n = 5]. The cytochrome P-450 epoxyeicosatrienoic acid (EET) metabolite 14,15-EET (5 x 10(-7) M) inhibited both apical and basolateral cotransport, whereas 8,9-EET and 11,12-EET had no significant effect. Although 20-hydroxyeicosatetraenoic acid inhibited apical cotransport, the inhibitor of omega-hydroxylase activity HET0016 did not reverse SNAP-mediated inhibition of apical cotransport. These data indicate that NO inhibits apical and basolateral Na(+)-K(+)-2Cl(-) cotransport in MMDD1 cells. The results suggest that the inhibitory pathway is independent of cGMP and might involve stimulation of a cytochrome P-450-dependent pathway.

Hyperbaric oxygen in the treatment of calciphylaxis: a case series

BACKGROUND

Calciphylaxis, also referred to as calcific uraemic arteriolopathy, is a syndrome associated with end-stage renal disease (ESRD), and causes necrotic skin ulcers, often leading to a fatal outcome. Hyperbaric oxygen (HBO(2)) therapy has been used to enhance wound healing, but its role in the treatment of calciphylaxis is unclear.

METHODS

We undertook a retrospective study of patients on renal replacement therapy with biopsy-proven calciphylaxis who were treated with HBO(2) between March 1997 and February 2000.

RESULTS

Five patients were treated with HBO(2): three patients were on continuous ambulatory peritoneal dialysis (CAPD) and two were on chronic haemodialysis therapy. None of the patients had uncontrolled hyperparathyroidism and none underwent parathyroidectomy. The patients each received 25-35 treatments of HBO(2) at 2.5 atmospheres for 90 min per treatment. Two of these patients had complete resolution of extensive necrotic skin ulcers, with no adverse effects of HBO(2) therapy. Both had improvement in wound area transcutaneous oxygen pressure (P(tc)O(2)) with administration of 100% oxygen when measurements were taken at normobaric and hyperbaric pressures. In the other three patients receiving HBO(2), the skin lesions did not resolve. P(tc)O(2) was measured in two of these patients, neither of whom showed improvement with 100% oxygen administered at normobaric pressure.

CONCLUSIONS

The data support a role for HBO(2) in the treatment of some patients with calciphylaxis, particularly as in the absence of uncontrolled secondary hyperparathyroidism there are few therapeutic options.