Dorset Medicines Advisory Group SHARED CARE GUIDELINE FOR THE USE OF PHOSPHATE BINDERS IN THE MANAGEMENT OF HYPERPHOSPHATAEMIA IN PATIENTS WITH CHRONIC KIDNEY DISEASE. INDICATION This document provides guidance for the prescribing of phosphate binders for the management of hyperphosphatemia in patients receiving haemodialysis or peritoneal dialysis and patients with chronic kidney disease stage 4 or 5 who are not receiving dialysis. This shared care guideline covers adult patients under the care of the Dorset Renal Unit. Patients with chronic renal failure have reduced ability to excrete phosphate. Phosphate accumulation enhances parathyroid activity and leads to the calcification of arteries, significantly contributing to the excess cardiovascular morbidity in these patients, especially in younger age groups. Adequate control of serum phosphate levels is thought to be beneficial for the prevention of vascular and cardiac calcification in patients with renal failure and control of parathyroid hormone. A number of oral phosphate binders are available which may be used in the context of a multiple therapeutic approach. These include calcium acetate, calcium carbonate, calcium acetate/magnesium carbonate, lanthanum, sevelamer and sucroferric oxyhydroxide. These products may be used in combination with 1-hydroxycholecalciferol (alfacalcidol) or one of its analogues and/or cinacalcet to control the development of secondary hyperparathyroidism and renal bone disease. A calcium-based phosphate binder is generally used as the initial phosphate binder therapy for the treatment for hyperphosphatemia. Calcium acetate is preferred over calcium carbonate due to its lower elemental calcium content for the equivalent phosphate binding capacity, however patient preference in formulation should be taken into consideration. A non-calcium-based phosphate binder should be used in patients who cannot tolerate a calcium-based phosphate binder, whose serum calcium exceeds 2.5mmol/L or whose parathyroid levels are less than 15pmol/L. Calcium-based and non-calcium-based phosphate binders may be used in combination if required to achieve target serum phosphate and calcium levels. Aluminium-based phosphate binders may be used if other phosphate binders are contraindicated, not tolerated or are ineffective. The calcium-based phosphates binders are amber drugs with shared care guidance. The use of calcium-based phosphate binders in patients who are not on dialysis is off-label, however their use in this patient group is in accordance with national guidance (NICE, 2013). Lanthanum and sevelamer are amber drugs with shared care guidance for patients with chronic kidney disease stage 4 or 5 who are not receiving dialysis. Lanthanum and sevelamer are red drugs for patients receiving haemodialysis or peritoneal dialysis. For patients receiving dialysis who were initiated on lanthanum or sevelamer prior to April 2020, the GP may continue to prescribe in accordance with this shared care guideline. For patients receiving dialysis that have been initiated on lanthanum or sevelamer after April 2020, prescribing should be maintained by the specialist. 1 Dorset Medicines Advisory Group AREAS OF RESPONSIBILITY FOR SHARED CARE Patients should be at the centre of any shared care arrangements. Individual patient information and a record of their preferences should accompany shared care prescribing guidelines, where appropriate. Transfer of clinical responsibility to primary care should only be considered where the person’s clinical condition is considered stable. Referral to the GP should only take place once the GP has agreed to this in each individual case, and the hospital or specialist will continue to provide prescriptions until a successful transfer of responsibilities. The GP should confirm the agreement and acceptance of the shared care prescribing arrangement and that supply arrangements have been finalised. The secondary/tertiary provider must supply an adequate amount of the medication to cover the transition period. The patient should then be informed to obtain further prescriptions from the GP. When clinical responsibility for prescribing is transferred to general practice, it is important that the GP, or other primary care prescriber, is confident to prescribe the necessary medicines. Shared care agreements play a key role in enabling primary care prescribers to prescribe medicines with which they may not initially be familiar. Clinical responsibility for prescribing is held by the person signing the prescription, who must also ensure adequate monitoring has taken place. The specialist may be consultant nephrologist, speciality registrar in renal medicine or specialist renal dietitian. REFERRAL AND INITIATION Shared Care is only appropriate if it provides the optimum solution for the patient. o Patients will only be referred to the GP once the GP has agreed in each individual case. o Arrangements to transfer treatment from secondary to primary care may be made from 3 months after initiation of treatment, once the condition has been stabilised. Specialist Responsibilities 1 To assess the patient and establish the need for a phosphate binder. 2 To initiate and titrate therapy to determine optimal dose level according to the agreed protocol for the use of phosphate binders in renal patients. The first three months of treatment will be prescribed through the Dorset Renal Unit. 3 To obtain consent from the patient’s GP to continue prescribing once treatment has been stabilised ensuring they are provided with appropriate prescribing information and any additional information requested. 4 To review patients regularly in clinic, monitor phosphate and calcium levels and undertake all necessary monitoring. 5 To notify the GP at regular intervals, up to every 6 months, to confirm that the patient has been reviewed and for supply to be continued for a 6-month period, results of necessary monitoring to be shared with the GP in this notification. 6 To be available for advice if the patient’s condition changes and to provide the GP with up-to-date information when changes are made to the patient’s prescription following consultant review. 7 To ensure that procedures are in place for the rapid re-referral of the patient by the GP. 8 To ensure the patient/ carer has given informed consent to their treatment. 9 To discontinue treatment if no longer thought to be beneficial. 2 Dorset Medicines Advisory Group General Practitioner Responsibilities 1 Initially, to refer the patient for specialist advice. 2 Where appropriate, to continue to supply the phosphate binder as per doses agreed with the specialist after the initial three-month titration period and once relevant information has been received and agreed with the consultant. 3 To deal with general health issues of the patient. 4 To liaise with the consultant regarding any complications of treatment. 5 To refer the patient to the specialist if the patient’s condition changes. Patient's role (or that of carer) 1 Report to the specialist or GP if he or she does not have a clear understanding of the treatment. 2 Attend appropriate consultant and GP appointments. 3 Share any concerns in relation to treatment with their phosphate binder. 4 Use written and other information on the medication, including taking their phosphate binder with meals and adhering to their prescribed diets. 5 Seek help urgently if suspect side effects, or otherwise unwell. SUPPORTING INFORMATION Patient Counselling Phosphate binders should be taken just before, during or directly after a meal or snack. Patients should adhere to prescribed diets. Duration of treatment Lifelong. Monitoring Requirements and Responsibilities All patients receiving phosphate binders will have their calcium, phosphate and parathyroid hormone levels routinely measured. Additionally, patients taking Osvaren® will have their magnesium levels monitored every 6 months. Results will be shared with the GP via Dorset Care Record Pregnancy and Breastfeeding Calcium carbonate is considered suitable for use in pregnant and breastfeeding women. There is limited or no data for the use of calcium acetate, calcium acetate/magnesium carbonate, lanthanum and sevelamer in pregnant women. Their use may be considered in pregnant women and a careful risk benefit analysis should be conducted for both mother and foetus. Calcium acetate may be used in pregnant and breastfeeding women if clearly indicated. The manufacturers of lanthanum recommend that lanthanum is not used during pregnancy. Sevelamer is less suitable for pregnant women as it may reduce the absorption of fat-soluble vitamins and folic acid. Osvaren® is not recommended for women who are breastfeeding as calcium acetate and magnesium carbonate may be excreted in human milk to such an extent that effects on the breastfed infant are likely. It is unknown whether sevelamer and lanthanum are excreted in human milk, however because of their low bioavailability, they are unlikely to be excreted in the breast milk in significant amounts. Sevelamer may cause vitamin deficiencies in the mother. 3 Dorset Medicines Advisory Group Contact Information Renal Secretaries 01305 255269 Dietitian Office 01305 255377 Dietitian Mobile 07833484301 4 Dorset Medicines Advisory Group BINDER LICENSED LICENSED CAUTIONS AND DRUG INTERACTIONS ADVERSE REACTIONS INDICATION DOSE CONTRAINDICATIONS CALCIUM CONTAINING BINDERS Calcium Acetate Correction of Initially one tablet Cautions: Increased risk of hypercalcaemia with Constipation, flatulence, hyperphosphatemia