Clinical Guideline Bone chemistry management in adult renal patients on dialysis

Transcription

1 Clinical Guideline Bone chemistry management in adult renal patients on dialysis This guidance covers how to: Maintain serum phosphate 0.8 to 1.7mmol/L 1 Maintain serum corrected calcium 2.1 to 2.5mmol/L 1 Maintain serum parathyroid hormone (PTH) 2-9x normal range (14 63 pmol/l) 1 Restrict daily intake (from phosphate-binding medicines) of elemental calcium to no more than 1500mg for stable patients, unless in special circumstances 2 General Information Patients will be referred by the nephrology team to a renal dietitian for advice on maintaining a lowphosphate diet (800 to 1000mg phosphorus per day). (N.B If patients are not eating well, dietary phosphate restrictions may be relaxed under dietetic supervision). Patients will be prescribed an appropriate dose of: A phosphate binding agent(s). An agent to control secondary hyperparathyroidism The renal dietitian and/or renal pharmacist will advise the patients on the timing and distribution of phosphate binders. Regular audit of the management of bone chemistry will be conducted in line with the Renal Association Guidelines This guideline also applies to failed renal transplant patients who now require dialysis. Blood Monitoring 1. Corrected calcium The guidance relates to calcium levels corrected for serum albumin: Corrected calcium (mmol/l) = 0.02(40 serum albumin) + serum calcium Check calcium once a month if serum calcium within normal range * If patient is hypercalcaemic (if nausea,vomiting or limb parasthesia occurs) or if hypocalcaemic check calcium once a week until it is back within normal range If patient is started on alfacalcidol, cinacalcet or paricalcitol, or following dose changes, check calcium after one week. 2. Phosphate Check once a month* Refer to Chart 1 to determine whether treatment is necessary 3. Parathyroid hormone (PTH) Check every three months. (N.B Clatterbridge dialysis unit: check monthly as per Fresenius guidelines). If on cinacalcet or paricalcitol check monthly until dose stable for 3 months then check 3 monthly. Refer to Chart 2 to determine whether treatment is necessary 4. Aluminium Check yearly. If patient taking Alucaps check three monthly. If serum aluminium >1.85micromol/L refer to aluminium toxicity in adult dialysis patients guidelines. *Blood samples should be taken: 1) At the beginning of each month, preferably in the morning, for peritoneal dialysis patients. 2) On the first Wednesday/Thursday of each month, prior to dialysis, for haemodialysis patients. Page 1 of 8

2 Phosphate-binding preparations (see Appendix 1a for cost comparisons) Trade name of phosphate binder Constituent and amount per tablet Amount of elemental calcium per tablet Administration method and timing in relation to meals Calcichew calcium carbonate 1.25g 500 mg Chew or suck with meals. PhosLo calcium acetate 667mg 169mg Swallow whole with meals Phosex calcium acetate 1000mg 250 mg Swallow whole with meals Alu-Caps aluminium hydroxide 475 mg Renagel Fosrenol sevelamer hydrochloride 800 mg lanthanum carbonate 500mg, 750mg, 1000mg Nil Nil Nil Swallow whole with meals Swallow whole with meals Chew with, or immediately after, meals Aluminium hydroxide (Alu-caps ) may be prescribed under the discretion of the clinician in resistant cases of hyperphosphataemia. Administration advice Phosphate binders should be taken at the appropriate time with relation to meals. Phosphate binders should not be taken within 2 hours of taking iron supplements. Phosphate binders should not be taken without food. Phosphate binders must be taken with phosphate containing food or snacks while patient is on dialysis Quantity of phosphate binders taken with each meal should be determined according to size of meal. Oral calcium may interfere with the absorption of biphosphonates, ciprofloxacin, levothyroxine and tetracycline. These agents should be taken at least two hours before or four to six hours after calcium. Aluminium hydroxide may reduce the absorption of antibiotics (eg, cefaclor, quinolones, tetracyclines). Aluminium hydroxide is contraindicated in patients with hypophosphataemia or porphyria. Accumulation in renal failure has been linked with neurotoxicity, osteomalacia and a reduced response to erythropoietin. Supply of bone chemistry medication Phosphate binders are supplied on prescription by GPs. Alfacalcidol can be prescribed by GPs or supplied to patients on the dialysis unit. Cinacalcet and paricalcitol are supplied by the hospital. If any dose or type of treatment is altered, started or stopped, a standard letter detailing the change will be completed by the renal dietitian, renal pharmacist or renal specialist nurse (using the CyberRen system), signed by a consultant nephrologist or a non-medical prescriber, and sent to the GP. Two copies of this letter must be produced one for the patient s medical notes and the other for the dialysis database. A standard letter will also be sent (by the renal dietician, renal pharmacist or renal specialist nurse) to the patient with details of their new/amended medication and to remind them to collect their new prescription from their GP. Page 2 of 8

3 Chart 1: Hyperphosphataemia pathway in adult renal patients on dialysis Serum phosphate >1.7mmol/l Check dialysis adequacy. Refer to dietician for dietary phosphate restriction. Corrected calcium* <2.3mmol/L Corrected calcium* 2.3mmol/L Calcium carbonate 1.25g (Calcichew ) three tablets/day with meals or Calcium acetate 667mg (PhosLo ) titrate up to nine capsules/day or Calcium acetate 1g (Phosex ) titrate up to six tablets/day with meals. Check bloods at next appointment. If corrected calcium <2.1mmol/L refer to consultant Phosphate >1.7mmol/L or if *Ca > 2.5mmol/L Check compliance with medication/diet and educate patient. Start sevelamer hydrochloride (Renagel ) 800mg three tablets/day with meals. Titrate in increments of three tablets/day until phosphate 1.7mmol/L or patient taking 9 sevelamer tablets per day. Consider stopping calcium-based binders if *Ca >2.5mmol/L If phosphate >1.7mmol/L and patient taking 9 sevelamer tablets/day or not tolerating sevelamer Continue to monitor. Phosphate binders may need to be reduced if phosphate falls <0.8mmol/L. No Phosphate >1.7mmol/L? Yes Check compliance with medication and educate patient. Stop sevelamer hydrochloride. Start lanthanum carbonate (Fosrenol ) 500mg three tablets/day with meals. Titrate as necessary to 750mg three tablets/day with meals and then 1000mg three tablets/day with meals until phosphate 1.7mmol/L or patient taking 3000mg/day. In some patients it may be necessary to start at a higher dose of lanthanum per day. If phosphate becomes >1.7mmol/L Check compliance with medication and educate patient. Refer to consultant if phosphate remains >1.7mmol/L. Notes: Calcium and phosphate are routinely monitored monthly for haemodialysis and CAPD patients. *Corrected calcium (mmol/l) = 0.02(40-albumin) + serum calcium Page 3 of 8

4 Secondary hyperparathyroidism pathway for adult renal patients on dialysis Preparations (see Appendix 1b for cost comparison) Drug Dose Effect on Calcium (*Ca) Alfacalcidol Daily or Pulsed weekly dose; start: 250nanograms per day, to be increased as tolerated. Consider weekly dosing if Ca >2.5mmol/L Increases *Ca. Review if *Ca >2.5mmol/L Calcitriol Paricalcitol Cinacalcet *Ca = calcium corrected for serum albumin Start: 250nanograms daily or 3 x weekly, to be increased as tolerated Start: 2micrograms 3 x weekly To be increased as tolerated Start at 30mg daily with largest meal of the day, maximum dose 180mg daily Increases *Ca level. Review if *Ca >2.5mmol/L Potential to increase *Ca. Start if *Ca mmol/L Review if *Ca >2.7mmol/L Can lower *Ca. Start if *Ca >2.7mmol/L Review if *Ca <2.1mmol/L Note: IV formulations should not be used unless the patient has absorption problems. Aim is to maintain parathyroid hormone levels between 14 and 63 pmol/l whilst ensuring *Ca is within the desired range ( mmol/L) Page 4 of 8

5 Chart 2: Hyperparathyroidism pathway for adult renal patients on dialysis *Ca = calcium corrected for serum albumin PTH= Parathyroid hormon No change necessary unless *Ca <2.1mmol/L or >2.5mmol/L if so, treat as per PTH >63pmol/L Monitor PTH 3 monthly (If taking cinacalcet or paricalcitol, check monthly until on a stable dose) Review need for current treatment and stop/reduce doses as appropriate PTH 14-63pmol/L PTH >63pmol/L PTH <14pmol/L + *Ca >2.5mmol/L + *Ca mmol/L + *Ca <2.1mmol/L See hypercalcaemia pathway for adult renal patients on dialysis (Chart 3, p7) Is *Ca >2.5mmol/L After 1 month? Yes If on alfacalcidol or calcitriol reduce dose; if on daily dose try a pulsed weekly dose If on paricalcitol increase dose if *Ca <2.7mmol/l; If on cinacalcet increase dose No Start alfacalcidol/calcitriol or increase dose of current PTH treatment if PTH >63pmol/L Start/Increase dose of alfacalcidol/calcitriol or Increase dose of paricalcitol or If on cinacalcet consider: 1. Replacing it with alfacalcidol,calcitriol or paricalcitol. 2. Add alfacalcidol (continue cinacalcet) 3. Adding calcium-based phosphate binder No Is *Ca still >2.5mmol/L after 1 month If *Ca <2.7mmol/L stop alfacalcidol or calcitriol (if taking) and consider paricalcitol If *Ca >2.7mmol/L consider cinacalcet Yes **if patient on paricalcitol or cinacalcet corrected Ca should be checked a week after starting or any dose changes** Please note if calcium not controlled with the above measures please refer to consultant Nephrologist. Page 5 of 8

6 Chart 3: Hypercalcaemia pathway for adult renal patients on dialysis Corrected calcium* >2.5mmol/L Reduce calcium in dialysate Check patient is not taking any over-the-counter calciumcontaining medicines such as Rennie, Tums, etc Stop calcium-based phosphate binders and convert to non-calciumbased binders (see phosphate binding preparations table on p2) Recheck calcium in a month Notes: *Corrected calcium (mmol/l) = 0.02(40-albumin) + serum calcium If corrected calcium* >2.50mmol/L. See hyperparathyroidism pathway for adult renal patients on dialysis (p6) Page 6 of 8

7 Appendix 1a: Cost Comparisons - Phosphate Binders Trade name of phosphate binder Constituent and amount per tablet Maximum maintenance dose* Cost per 28 days** Cost per original pack** Calcichew Phosex PhosLo *** Alu-Caps Renagel Fosrenol Calcium carbonate 1.25g Calcium acetate 1000mg Calcium acetate 667mg Aluminium hydroxide 475 mg Sevelamer hydrochloride 800 mg Lanthanum carbonate 500mg 750mg 1000mg 3 tablets/day tablets 6 tablets/day tablets 9 capsules/day capsules 9 capsules/day capsules 9 tablets/day tablets 3000mg/day tablets *Maximum maintenance dose as per Wirral and Chester Nephrology Units Clinical Guidance for the Management of Bone Chemistry. **Prices based on current costing including VAT for January *** The Scottish Medicines Consortium (SMC) has accepted calcium acetate (PhosLo ) for use in NHS Scotland for prevention/treatment of hyperphosphataemia in patients with advanced renal failure on dialysis 3. Page 7 of 8

8 Appendix 1b: Cost comparison - PTH control Preparation Strength Cost per original pack (pack size) Alfacalcidol capsules Alfacalcidol liquid Alfacalcidol injection Calcitriol capsules Cinacalcet tablet Paricalcitol capsules Paricalcitol injection 250nanogram 500nanogram 1 microgram 2microgram in 1mL 2microgram in 1mL 250nanogram 500nanogram 30mg 60mg 90mg 1microgram 2microgram 4microgram 5 microgram in 1mL Prices based on current costing including VAT for January (30) 4.80 (30) 6.48 (30) (10mL) (10 x 1mL) (100) (30) (28) (28) (28) (28) (28) (28) (5 x 1mL) References 1. UK Renal Association Clinical Practice Guidelines 2010: 2. National Kidney Foundation. K/DOQI Clinical Practice Guidelines for Bone Metabolism and Disease in CKD. American Journal of Kidney Disease 2003;42:suppl Scottish Medicines Consortium. Calcium acetate (Phoslo): advice. Available at: (accessed 26 April 2011). Page 8 of 8