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Chronic Kidney Disease: Management of Complications Pharmacotherapy II Second Semester 2017 References ο Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney inter., Suppl. 2013; 3: 1-150. ο Kidney Disease: Improving Global Outcomes (KDIGO) Anemia Work Group. KDIGO Clinical Practice Guideline for Anemia in Chronic Kidney Disease. Kidney inter., Suppl. 2012; 2: 279β335. ο KDIGO Clinical Practice Guidelines for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) CKD complications ο Complications begin to develop as kidney disease progresses, most often when patients reach to eGFR is <60 mL/minute/1.73 m2 (G3a-G5). ο Among these complications are: ο ο ο ο ο ο ο fluid and electrolyte abnormalities, anemia, hyperphosphatemia, hyperparathyroidism, metabolic acidosis, cardiovascular complications, poor nutritional status. ο Often, these complications go unrecognized or are inadequately managed during the earlier stages of CKD, leading to poor outcomes by the time a patient is in need of dialysis therapy. Metabolic Effects of Progressive Kidney Disease Cardiovascular Hypertension Congestive heart failure Pericarditis Atherosclerosis Arrhythmias Metastatic calcifications Dermatologic Altered pigmentation Pruritus Endocrine Calcium-phosphorous imbalances Hyperparathyroidism Metabolic bone disease Altered thyroid function Altered carbohydrate metabolism Hypophyseal-gonadal dysfunction Decreased insulin metabolism Erythropoietin deficiency Fluid, Electrolyte, and Acid-Base Effects Fluid retention Hyperkalemia Hypermagnesemia Hyperphosphatemia Hypocalcemia Metabolic acidosis Gastrointestinal Anorexia Nausea, vomiting Delayed gastric emptying GI bleeding Ulcers Hematologic Anemia Bleeding complications Immune suppression Musculoskeletal Renal bone disease Amyloidosis Neurologic Lethargy Depressed sensorium Tremor Asterixis Muscular irritability and cramps (i.e., restless legs syndrome) Seizures Motor weakness Peripheral neuropathy Coma Psychological Depression Anxiety Psychosis Miscellaneous Reduced exercise tolerance 1) Fluid And Electrolyte Abnormalities: Sodium and Water ο Patient with CKD or ESKD maintain sodium balance but are volume expanded ο the most common manifestation of increased intravascular volume is systemic hypertension ο The goal in managing sodium and water balance is to maintain a normal serum sodium concentration while preventing fluid overload or volume depletion (i.e., maintaining hemodynamic stability). ο By achieving these goals, the risk of developing hypertension secondary to volume overload is also reduced, although hypertension is already present in many patients at G3 and G4. secondary to the defect in urinary concentrating ability as the result of an increase in FeNa = plasma Management ο The ability of the kidney to adjust to abrupt changes in sodium intake is greatly diminished in patients with ESKD. ο Sodium restriction beyond a no-added-salt diet should not be recommended except in the face of hypertension or edema.(2-4 g/day). ο Saline-containing IV solutions should be used cautiously in patients with CKD because the kidneyβs ability to excrete a salt load is impaired and such patients are prone to volume overload ο Fluid restriction is generally unnecessary provided sodium intake is controlled, although fluid intake between dialysis sessions is generally limited for hemodialysis patients (avoid < 2 L/d) (depends on urine output). ο Diuretic therapy is often necessary to control edema or blood pressure. ο Loop diuretics, particularly when administered by continuous infusion, increase urine volume and renal sodium excretion. ο Thiazide diuretics are ineffective in patients with a GFR below 30 mL/min. The possible exception is use of the thiazide-like diuretic, metolazone, which may retain its effect at reduced eGFRs. ο As kidney failure progresses, manifestations of excess fluid accumulation develop that are resistant to more conventional interventions, and dialysis will be required to control volume status. 2) Potassium Homeostasis (Hyperkalemia): ο Hyperkalemia can result from a combination of factors, including: ο diminished renal potassium excretion, ο redistribution of potassium into the extracellular fluid owing to metabolic acidosis, ο excessive potassium intake. ο Rare if GRF >15 without an endogenous or exogenous load of potassium. ο Hyperkalemia is defined as a serum potassium concentration greater than 5.5 mEq/L. ο It can be further classified according to its severity: ο mild hyperkalemia (serum potassium 5.5 to 6 mEq/L); ο moderate hyperkalemia (6.1 to 6.9 mEq/L); ο severe hyperkalemia (>7 mEq/L). ο The chronic goal is to maintain potassium concentrations of approximately 4.5 to 5.5 mEq/L Hyperkalemia β Clincal presentation ο Frequently asymptomatic; however, the patient may complain of heart palpitations or skipped heartbeats. ο The earliest ECG change (serum potassium 5.5 to 6 mEq/l) is peaked T waves. ο The sequence of change with further increases is: ο ο ο ο prolongation of the PR interval , widening of the QRS complex, loss of the P wave, merging of the QRS complex with the T wave resulting in a sine-wave pattern. ο Hyperkalemic ECG changes are uncommon at potassium concentrations of <7 mEq/L, but occur regularly at concentrations >8 mEq/L. ο Ventricular arrhythmias or cardiac arrest may ensue if no effort to lower serum potassium Hyperkalemia - Management ο Generally, treatment is unnecessary if the potassium concentration is <6.5 mEq/L and there are no ECG changes. ο If potassium concentrations rise above 6.5 mEq/L, and especially if they are accompanied by neuromuscular symptoms or changes in the ECG, treatment should be instituted. ο Chronic management involves prevention of hyperkalemia by: ο limiting potassium intake to 50 to 80 mEq/day ο Homework: what constitutes a low potassium diet? ο avoiding the use of agents that could elevate potassium levels. ο Homework: what are these agents? ο Constipation in patients with CKD can interfere with colonic potassium excretion; therefore a good bowel regimen is important. ο Homework: What is good bowel regimen? Grains Foods prepared with white flour (eg, pasta, bread), white rice Beverages Non-dairy creamer, fruit punch, drink mixes (eg, Kool-Aid), tea (<2 cups or 16 ounces per day), coffee (<1 cup or 8 ounces per day) Sweets Angel or yellow cake, pies without chocolate or high-potassium fruit, cookies without nuts or chocolate Fruits Apples (1), apple juice, applesauce, apricots (canned), blackberries, blueberries, cherries, cranberries, fruit cocktail (drained), grapes, grape juice, grapefruit (½), mandarin oranges, peaches (½ fresh or ½ cup canned), pears (1 small fresh or ½ cup canned), pineapple and juice, plums (1 whole), raspberries, strawberries, tangerine (1 whole), watermelon (1 cup) Vegetables Alfalfa sprouts, asparagus (6 spears), green or wax beans, cabbage (cooked), carrots (cooked), cauliflower, celery (1 stalk), corn (½ fresh ear or ½ cup), cucumber, eggplant, kale, lettuce, mushrooms (fresh), okra, onions, parsley, green peas, green peppers, radish, rhubarb, water chestnuts (canned, drained), watercress, spinach (raw, 1 cup), squash (yellow), zucchini Proteins Chicken, turkey (3 ounces), tuna, eggs, baloney, shrimp, sunflower or pumpkin seeds (1 ounce), raw walnuts, almonds, cashews, or peanuts (all 1 ounce), flax seeds (2 tablespoons ground), unsalted peanut butter (1 tablespoon) Dairy products Cheddar or Swiss cheese (1 ounce), cottage cheese (½ cup) HW: low-potassium diet These foods have a low level of potassium (less than 250 mg potassium per serving on average). You can eat these low-potassium foods, but be sure to watch your portion size since potassium can quickly add up if you eat a large portion. Unless noted, one serving is ½ cup (4 ounces) Agents that can cause hyperkalemia. ο Medication that interferes with urinary excretion: ο ACE inhibitors and angiotensin receptor blockers ο Potassium-sparing diuretics (e.g. amiloride and spironolactone) ο NSAIDs such as ibuprofen, naproxen, or celecoxib ο The calcineurin inhibitor immunosuppressants cyclosporine and tacrolimus ο The antibiotic trimethoprim ο The antiparasitic drug pentamidine ο In constipation use: potassium-binding resins such as sodium polystyrene sulfonate (Kayexalate) Hyperkalemia - Management ο Acute management involves: ο reversal of cardiac effects with calcium administration (antagonize membrane effects of potassium) ο reduction of serum potassium which can be achieved by shifting potassium intracellularly with administration of: ο glucose and insulin, ο Ξ²-adrenergic agonists, ο alkali therapy (if metabolic acidosis is a contributing factor) ο Removing excess potassium from the body ο Loop or thiazide diuretics ο exchange resins to remove potassium ο dialysis using a low-potassium dialysate bath Therapeutic alternatives for the management of hyperkalemia 3) Metabolic Acidosis: ο A clinically significant metabolic acidosis is commonly seen when the GFR drops below 20-30ml/min. ο The major factors responsible for development of metabolic acidosis in advanced kidney disease: ο Reduced bicarbonate reabsorption ο impaired production of ammonia by the kidneys ο Consequences of metabolic acidosis include: ο renal bone disease (bone buffering of some of the excess hydrogen ions is associated with ο ο ο ο the release of calcium and phosphate from bone, i.e. promoting bone resorption), Fatigue and decreased exercise tolerance, reduced cardiac contractility, increased vascular irritability , protein catabolism (Uremic acidosis can increase skeletal muscle breakdown and diminish albumin synthesis) ο The goals of therapy for patients with CKD are: ο to normalize the pH of the blood (pH of approximately 7.35 to 7.45) ο maintain the serum bicarbonate within the normal range (22 to 28 mEq/L). Metabolic acidosis - Management ο Asymptomatic patients with mild acidosis (bicarbonate of 12 to 20 mEq/L; pH of 7.2 to 7.4) generally do not require emergent therapy and gradual correction over days to weeks is appropriate. ο When plasma bicarbonate β< 20 mEq/L, give NaHCO3 orally ο Each 650-mg tablet of sodium bicarbonate provides 8 mEq of sodium and 8 mEq of bicarbonate. ο Dose (mEq)= 0.5 x WT x (24 β Serum bicarbonate) ο The calculated amount of bicarbonate replacement therapy (in milliequivalents [or in mmols]) should be administered over several days to prevent volume overload from excessive sodium intake. ο ο ο ο Should be administered over several days to avoid volume overload from Na. Daily dose should not exceed 0.5 mEq/kg/day and should be given in divided doses GI distress from carbon dioxide production Homework: what are Bicitra and Polycitra and what are their uses. ο Patients with severe acidosis (serum bicarbonate <8 mEq/L; pH <7.2) may require IV therapy ο Bicitra contain 1 mEq/mL (1 mmol/mL) of sodium and the equivalent of 1 mEq/mL (1 mmol/mL) of bicarbonate as sodium citrate/citric acid. Citrate is metabolized in the liver to bicarbonate, and citric acid is metabolized to CO2 and water. ο Polycitra, which contains potassium citrate (1 mEq/mL [1 mmol/mL] of sodium, 1 mEq/mL [1 mmol/mL] of potassium, and 2 mEq/mL [2 mmol/mL] of bicarbonate) should not be used in patients with severe CKD because of the risk of hyperkalemia. Other Electrolyte and Metabolic Disturbances of CKD ο Hypermagnesemia ο is due to decreased elimination of magnesium by the kidney. ο Magnesium is eliminated by the kidney to the extent required to achieve normal serum magnesium concentrations (1.7 to 2.2 mg/dL) until eGFR is <30 mL/minute/1.73 m2. ο Serum magnesium concentrations <5 mEq/L rarely cause symptoms. ο Higher concs can lead to nausea, vomiting, lethargy, confusion, and diminished tendon reflexes, ο Severe hypermagnesemia may depress cardiac conduction. ο The risk of hypermagnesemia can be reduced by ο avoiding magnesium-containing antacids and laxatives ο use of magnesium-free dialysate in patients with stage 5 CKD requiring dialysis. Other Electrolyte and Metabolic Disturbances of CKD ο Hyperphosphatemia ο is a result of decreased phosphorus elimination by the kidneys ο patients should reduce dietary phosphorus to 800 to 1,000 mg/day while maintaining adequate nutritional needs. ο Phosphorus-containing laxatives and enemas should also be avoided. ο Hyperphosphatemia is associated with low serum calcium concentrations. ο Asymptomatic Hyperuricemia. ο Happen due to diminished urinary excretion of uric acid. ο In the absence of a history of gout or urate nephropathy, asymptomatic hyperuricemia does not require treatment. 4) Anemia: ο Anemia appears as early as G3 stage ο Usually is normochromic & normocytic ο The primary cause of anemia in patient with CKD or ESKD is erythropoietin (EPO) deficiency. ο Other factors include: ο decreased lifespan of red blood cells secondary to uremia, ο blood loss from frequent phlebotomy and HD, GI bleeding, ο severe hyperparathyroidism, protein malnutrition, severe infections, and ο ο ο ο inflammatory conditions uremic toxins may inhibit the production of EPO, the bone marrow response to EPO, and the synthesis of heme. iron deficiency ο microcytic hypochromic pattern vitamin B12 & folate deficiency, occurs more frequently in dialyzed patients since folic acid is removed by dialysis (rare in other stages of CKD) ο macrocytic anemia Aluminum intoxication (RBCs are typically microcytic). The major source is aluminium-containing antacids. Definition and identification of anemia in CKD ο The recommended thresholds for diagnosis and evaluation of anemia should not be interpreted as being thresholds for treatment of anemia but simply for the identiο¬cation of this complication. Practice preferences with respect to treatment strategies should be directed according to local resources. Evaluation of anemia in people with CKD ο To identify anemia in people with CKD measure Hb concentration: ο ο ο ο when clinically indicated in people with GFR<60 ml/min/1.73 m2 (GFR categories G1-G2); at least annually in people with GFR 30-59 ml/min/1.73 m2 (GFR categories G3a-G3b); at least twice per year in people with GFR <30 ml/min/1.73 m2 (GFR categories G4-G5). at least every 3 months in patients with CKD 5HD and CKD 5PD Anemia - Clinical presentation and diagnosis ο Pallor and fatigue are the earliest clinical signs, with other manifestations (exertional dyspnea, dizziness, headache) developing as anemia worsens progressively with declining kidney function ο A significant consequence of anemia is development of left ventricular hypertrophy (LVH), further contributing to cardiovascular complications and mortality in patients with CKD ο CHF, angina ο Early and aggressive treatment of anemia of CKD before the development of stage 5 CKD is important. β’ A more complete and regular workup for anemia of CKD is recommended for patients with an eGFR of <60 mL/minute/1.73 m2. This workup includes: β’ monitoring of hemoglobin and hematocrit, β’ assessment of iron indices with correction if iron deficiency is present, β’ evaluation for sources of blood loss, such as bleeding from the GI tract. Laboratory tests in the evaluation of anemia MCV=(Hct/RBC Count) MCHC=(Hgb/Hct) MCH=(Hgb/RBC Count) % Transferrin saturation = (Serum iron/TIBC) x 100 RBC Distribution Width = (Standard deviation of MCV ÷ mean MCV) × 100 Anemia β Goals of therapy ο The desired outcomes of anemia management are: ο to increase oxygen-carrying capacity, ο decrease signs and symptoms of anemia, ο improve the patientβs quality of life, ο decrease the need for blood transfusions. ο Achievement of these goals requires a combination of an ESA and iron supplementation to promote and maintain erythropoiesis. ο Hb is the preferred monitoring parameter for red blood cell production because, unlike Hct, its concentration is not affected by blood storage conditions and instrumentation used for analysis. Parameter Hb KDOQI KDIGO ND-CKD and PD-CKD HD-CKD ND-CKDa HD and PD-CKDa Hb 11β12 g/dL Hb 11β12 g/dL If Hb β₯10 g/dL, do not initiate an ESA Do not use ESAs to exceed Hb of 13 g/dL Do not use ESAs to exceed Hb of 13 g/dL Use ESAs to avoid drop in Hb to <9 g/dL by starting ESA when Hb is between 9 and 10 g/dL If Hb <10 g/dL, consider rate of fall of Hb, prior response to iron, risk of needing a transfusion, risk of ESA therapy, and presence of anemia symptoms before initiating an ESA Do not use ESAs to maintain Hb above 11.5 g/dL Do not use ESAs to maintain Hb above 11.5 g/dL TSatb (goal during ESA therapy) >20% (>0.20) >20% (>0.20) >30% (>0.30) >30% (>0.30) Serum ferritinb (goal during ESA therapy) >100 ng/mL >200 ng/mL >500 ng/mL >500 ng/mL a The KDIGO expert panel considered the quality of the evidence to be low or very low. b If TSat and serum ferritin are below suggested levels, consider iron supplementation if goal is to increase Hb and/or decrease ESA dose. Note: Serum ferritin is an acute-phase reactantβuse clinical judgment when above 500 ng/mL. Target Hemoglobin and Use of ESAs ο Initiation of ESA therapy should be considered in all CKD patients when Hb is between 9 and 10 g/dL and in nondialysis patients when the following additional criteria are met: ο (a) the rate of Hb decline indicates the likelihood of requiring a RBC transfusion and ο (b) reducing the risk of alloimmunization and/or other RBCtransfusion-related risks is a goal. ο According to the labeling for the available ESAs, the ESA dose should be decreased or interrupted when Hb is above 10 g/dL in CKD patients not receiving dialysis or above 11 g/dL in patients receiving dialysis. This is in contrast to the KDOQI and more recent KDIGO recommendations. New KDIGO guidelines The 2012 KDIGO guidelines ο suggested that ESAs not be started among adult non-dialysis CKD patients with Hgb concentrations β₯10 g/dL. ο For non-dialysis CKD patient with Hgb <10 g/dL, the decision to start ESAs should be individualized based upon: ο ο ο ο ο the rate of fall in Hgb concentration, prior response to iron therapy, risk of needing a transfusion, the risks related to ESA therapy the presence of symptoms. ο Among dialysis patients, KDIGO suggests initiating ESAs when the Hgb concentration is below 10 g/dL. ο The KDIGO 2012 guidelines suggest that ESAs should generally not be used to maintain Hgb concentrations above 11.5 g/dL, but that individualization of therapy will be necessary as some patients may have improvements in quality of life at Hgb β₯11.5 g/dL and will be prepared to accept the risks . The KDIGO guidelines recommended that ESAs not be used to maintain Hgb β₯13 g/dL. ο The 2012 KDIGO guidelines recommended that ESAs be used with great caution if at all in CKD patients with active malignancy, especially if cure is anticipated , or with a history of stroke or a history of malignancy. Iron Status ο Iron supplementation is required by most CKD patients receiving an ESA because of the increased iron demand that results from stimulation of red blood cell production. As CKD worsens, a progressive decline in Hb despite ESA therapy may be observed. ο Iron indices that should be monitored include: ο TSat, an indicator of iron immediately available for delivery to the bone marrow ο (Transferrin is the carrier protein for iron and, as a protein, may be affected by nutritional status) ο serum ferritin, an indirect measure of storage iron. ο Serum ferritin is an acute-phase reactant, meaning it may be elevated under certain inflammatory conditions and give a false indication of storage iron. ο The content of hemoglobin in reticulocytes (CHr) is also recommended as a parameter to assess iron status in hemodialysis patients, although it is not commonly used in clinical practice.. Anemia - Management ο Nonpharmacologic Therapy ο Nonpharmacologic therapy for anemia of CKD includes maintaining adequate dietary intake of iron as well as folate and B12. ο Patients on hemodialysis or peritoneal dialysis should be routinely supplemented with water-soluble vitamins (vitamins B, C, and folic acid) as these vitamins are often depleted with dialysis therapy. ο A relatively small amount of dietary iron, approximately 1 to 2 mg (or approximately 10%), is absorbed each day, primarily in the duodenum. Although there is some debate as to whether GI absorption of iron is significantly altered in patients with severe CKD, it is clear that oral intake from dietary sources alone is insufficient to meet the increased iron requirements from initiation of ESA therapy. ο Pharmacologic Therapy ο Pharmacologic therapy for anemia of CKD is based on a foundation of ESA therapy to correct erythropoietin deficiency and iron supplementation to correct and prevent iron deficiency caused by ongoing blood loss and increased iron demands associated with the initiation of erythropoietic therapy. ο Iron supplementation is first-line therapy for anemia of CKD if iron deficiency is diagnosed, and for some patients the target Hb may be achieved without concomitant ESA therapy. For most individuals with advanced CKD, however, combined therapy with iron and an ESA is required. Anemia - Management 1) Iron (Parenteral and Oral Form) ο Anemia therapy in patients with CKD requires effective use of iron agents, guided by appropriate testing of iron status. Efficacy of iron therapy appears not to be limited to patients with evidence of iron deficiency. ο Thus, the goals of iron therapy are: ο to avoid storage iron depletion, ο prevent iron-deficient erythropoiesis, ο achieve and maintain target Hgb levels ο Iron status tests should be performed as follows: ο Every month during initial ESA treatment ο At least every 3 months during stable ESA treatment or in patients with HD-CKD not treated with an ESA Iron preparations - Oral Oral ferrous sulphate (glutamate, fumarate) ο 200mg/day of elemental iron taken on empty stomach in 2-3 doses ο Patients should be advised to take oral iron on an empty stomach to maximize absorption, unless side effects prevent this strategy. ο In case of GI complaints: ο oral iron can be taken with small snack /or ο ferrous sulphate solution, iron polysaccharide complex or sustained-release preparation may be used but with the latter two bioavailability is the problem ο Patients should be counseled on potential drug interactions with oral iron (e.g., antacids, quinolones) and GI side effects (e.g., nausea, abdominal pain, diarrhea, constipation, dark stools). ο Food and CaCO3 delay iron absorption ο iron should be taken 1 hr before or 2 hr after CaCO3 ο Noncompliance with therapy is a primary cause of therapeutic failure with oral iron. Oral Iron Preparations Iron Product Common Agents and Available Elemental Iron per Units Unit Ferrous sulfate Fer-In-Sol (75 mg/0.6 mL) 75 mg Feosol (200 mg) 65 mg Ferrous sulfate, various preparations 65 mg (325 mg) Slow FE (160 mg) 50 mg Ferrous fumarate Ferrous fumarate, various preparations 99 mg (300 mg) Femiron (63 mg) 20 mg Nephro-Fer (350 mg) 115 mg Vitron-C (65-125 mg) 65 mg Ferrous gluconate Ferrous gluconate, various (325 mg) 36 mg Fergon (240 mg) 27 mg Polysaccharide iron Niferex (50 mg) 50 mg Hytinic (150 mg) 150 mg Heme iron Proferrin-ES (12 mg) 12 mg polypeptide Number of Units Per Daya 2β3 3β4 3β4 4 2 10 2 3 5 6 4 1β2 17 Differences between iron products ο The ferrous form of iron is absorbed three times more readily than the ferric form. ο Although ferrous sulfate, ferrous gluconate, and ferrous fumarate are absorbed almost equally, each contains a different amount of elemental iron. Iron-drug interactions Iron preparation - Parenteral Parenteral iron therapy: The IV iron preparations currently available are: ο iron dextran (INFeD and Dexferrum), ο ferric gluconate (Ferrlecit), ο iron sucrose (Venofer). ο Ferumoxytol (Feraheme ) ο Iron dextran ο 100mg during each HD session by IV push over 2 min for 10 session ο 50 mg each week during dialysis for 10 weeks ο ADR: ο Arthralgias, myalgias, serum sickness-like syndrome, hypotension. ο A one-time dose of 25mg in adults should be administered IV before initiating therapy to detect small risk of anaphylaxis ο ferric gluconate and iron sucrose and ferumoxytol have less ADR ο no need for test dose ο Administration of IV iron also introduces a risk of iron overload. (How can this be prevented and treated?) Parenteral Iron Preparations Iron Compounds FDA-Approved FDA-Approved Dosing Indications Patients with iron IV push: 100 mg over 2 min (25deficiency in whom oral mg test dose required) iron is unsatisfactory Iron Dextran (INFeD, Watson Pharma Inc., Morrisontown, NJ, and DexFerrum, American Regent, Inc.. Shirley, NY)b Sodium ferric Adult and pediatric HD gluconate (Ferrlecit, patients age 6 years and Sanofi-Aventis, older receiving ESA Dagenham, Essex, therapy c England) a Small Warnings Black box (risk of anaphylacti c reactions) IV push (adult): 125 mg over General 10 min IV infusion (adult): 125 mg in 100 mL of 0.9% NaCl over 60 min IV infusion (pediatric): 1.5 mg/kg in 25 mL of 0.9% NaCl over 60 min; maximum dose 125 mg Dose Rangesa 25β1,000 mg 62.5β1,000 mg dosing ranges (e.g., 25β150 mg per week) generally used for maintenance regimens. Larger doses (e.g., 1 g) should be administered in divided doses. b Supplied in 2-mL single-dose vials containing 50 mg of elemental iron per mL. c Available in colorless glass ampules containing 62.5 mg elemental iron (12.5 mg/mL). Parenteral Iron Preparations-contβd Iron Compounds Iron sucrose (Venofer, American Regent, Inc., Shirley, NY)d Ferumoxytol (Feraheme, AMAG Pharmaceuticals, Lexington, MA)e d Supplied FDA-Approved Indications Adult and pediatric HD patients age 2 years and older FDA-Approved Dosing Warnings IV push: 100 mg over 2β5 min General IV infusion: 100 mg in maximum of 100 mL of 0.9% NaCl over 15 min Adult and pediatric ND- IV push: 200 mg over 2β5 min on 5 CKD patients age 2 years different occasions within 14-day and older period Adult and pediatric HD IV infusion: 2 infusions, 14 patients age 2 years and days apart, of 300 mg in a older maximum of 250 mL of 0.9% NaCl over 1.5 h, followed by 1 infusion, 14 days later, of 400 mg in a maximum of 250 mL of 0.9% NaCl over 2.5 h Adult patients with ironIV: 510 mg (17 mL) as a single General deficiency anemia dose, followed by a second 510 associated with chronic mg dose 3β8 days after the kidney disease initial dose (rate of 1 mL or 30 mg/second) Dose Rangesa 25β1,000 mg 510 mg in 5-mL single-dose vials containing 100 mg elemental iron (20 mg/mL). e Supplied as a 17-mL single-use vial containing 510 mg elemental iron (30 mg/mL). Dosing and admiration of iron ο If oral therapy is initiated, the recommended dose is 200 mg of elemental iron per day. With numerous oral agents to choose from, the best option is one that provides adequate elemental iron with the fewest number of dosage units required per day. ο KDIGO guidelines suggest a 1- to 3-month trial of oral therapy in the nondialysis CKD population. ο For the hemodialysis population, administration of 1 g of IV iron is recommended to initially replete patients with an absolute iron deficiency. : ο Typical repletion dosing regimens for IV iron are 100 mg as iron sucrose or iron dextran over 10 dialysis sessions, ο or 125 mg of sodium ferric gluconate over 8 dialysis sessions (see Table 29-10). ο Ferumoxytol is administered as 510 mg at a rate not to exceed 30 mg/s (1 mL/s) with a second dose given within 3 to 8 days, a higher dose and administration rate compared with other available IV iron formulations. ο Without ongoing iron supplementation, many patients quickly become iron deficient. To prevent iron deficiency, maintenance doses of IV iron are administered in hemodialysis patients (e.g., iron sucrose or iron dextran 25 to 100 mg/wk; sodium ferric gluconate 62.5 to 125 mg/wk) based on evidence of improved Hb and lower ESA doses with these regimens. According to the labeling for the available ESAs, the ESA dose should be decreased or interrupted when Hb is above 10 g/dL in CKD patients not receiving dialysis or above 11 g/dL in patients receiving dialysis Anemia β Management (contβd) 2) Folic Acid 1 mg/day 3) Blood Transfusion ο Is no longer the main therapy due to risk of iron overload, infections, suppression of erythropoietin. ο Only use in case of persistent anemia, severe symptoms and substantial blood loss(acute bleeding). 4) Erythropoiesis-Stimulating Agent (ESA) ο The erythropoietin deficiency evident in patients with CKD can be corrected by the exogenous administration of erythropoiesisstimulating agents. Two such agents are currently available: ο Epoetin alfa (recombinant human erythropoietin [rHuEPO - Epogenβ’ or Procritβ’]) ο Darbepoetin alfa (Aranespβ’), a unique molecule that stimulates erythropoiesis with a longer half-life than rHuEPO Dosing and administration of ESA ο Recommended starting doses of ESA are listed inTable 29-11. Less frequent dosing ofepoetin alfa (e.g., every 1 to 2 weeks) is effective and may be preferred for stage 3 and 4 CKD patients since these patients are seen in the outpatient clinical setting on a relatively infrequent basis.Subcutaneous dosing is also more convenient in this population and in peritoneal dialysis patients who do not have regular IV access. Conversion tables for patients who are to be switched from epoetin alfa (units per week) to darbepoetin alfa(micrograms per week) are available in the labeling information for darbepoetin. ο When starting an ESA, Hb levels should be monitored at least weekly until stable and then at least monthly. Dose adjustments should be made based on Hb response with consideration of data on risks associated with higher Hb levels and rate of rise in Hb. An acceptable rate of increase in Hb is 1 to 2 g/dL (10 to 20 g/L; 0.62 to 1.24 mmol/L) per month. Dosing and administration of ESA ο As a general rule, ESA doses should not be increased more frequently than every 4 weeks, although decreases in dose may occur more frequently in response to a rapid rate of rise in Hb. ο Based on labeling for ESAs, the dose should be reduced by at least 25% if the Hb increases by more than 1 g/dL (10 g/L; 0.62 mmol/L) in a 2-week period. ο The dose should be reduced or temporarily discontinued if the Hb level approaches or exceeds 11 g/dL (110 g/L; 6.83 mmol/L) in dialysis patients (all ESAs) or 10 g/dL (100 g/L; 6.21 mmol/L) in patients with CKD not requiring dialysis. ο KDIGO recommendations advocate a decrease in dose as opposed to withholding the ESA when a decrease in Hb concentration is desired. A 25% increase in dose may be considered if the Hb has not increased by 1 g/dL (10 g/L; 0.62 mmol/L) after 4 weeks of ESA treatment and if no causes of resistance to the ESA have been identified. ο For patients who do not respond adequately over a 12-week escalation period, an increase in ESA dose is unlikely to improve response and may increase risks. Initial hyporesponsiveness to ESAs should be considered when there is no increase in Hb from baseline after the first month of appropriate weight-based dosing. Acquired ESA hyporesponsiveness may be suspected when patients previously on a stable ESA dose require two increases in ESA doses up to 50% beyond the stable dose. ο in these situations repeat escalations in ESA dose beyond double the initial weight-based dose should be avoided. ο The lowest dose of ESA should be used to maintain a Hb level sufficient to reduce the need for RBC transfusions. Figure 29-6 provides an approach to management of anemia using ESAs and iron therapy in patients with CKD. Anemia β Management (contβd) ο Improvement of anemia with erythropoiesis-stimulating agents is associated with some clinical benefits. These include: ο ο ο ο ο ο improvements in quality of life increased energy levels greater capacity for work and exercise restored sexual function improved appetite and participation in social activities reduced depression and fatigue ο Human ERYthropoetin-Epoetin Alfa ο SC administration is preferred because lower doses can be administered less frequently and cost is lower than with IV administration ο Based on the half-life of epoetin alfa (8.5 hours IV, 24.4 hours SC), the total weekly dose is usually divided into smaller doses, administered one to three times per week with SC administration and three times per week for IV administration in patients on HD Anemia β Management (contβd) ο ESA: Darbepoetin alfa: ο The newer erthropoietic agent, has a longer half life and prolonged biological activity therefore, doses are administered less frequently, starting at once a week or every other week when administered IV or SC. ο Starting dose in patients not previously receiving epoietin-alpha therapy is 0.45 mcg/kg IV or SC once weekly. ο For patients previously receiving epoietin alpha: conversion doses is listed in table (2-3 x/week ο weekly, weekly ο every other week) ο Extended dosage interval β up to 4 weeks shown to be successful ο In dialysis and nondialysis patients with CKD receiving ESA therapy, the selected Hgb target should generally be in the range of 11.0 to 12.0 g/dL and not be greater than 13g/dL. ο favors subcutaneous administration in non-hemodialysis-CKD patients and intravenous (IV) administration in HD (hemodialysis)-CKD patients Estimated starting dose schedule of darbepoetin alfa according to the previous rHuEPO regimen in patients with CKD. ADR of ESA The most common causes of resistance are iron deficiency, acute illness, catheter insertion, hypoalbuminemia, elevated C-reactive protein, chronic bleeding, aluminum toxicity, malnutrition, hyperparathyroidism, cancer and chemotherapy, AIDS, inflammation, and infection. According to the labeling for the available ESAs, the ESA dose should be decreased or interrupted when Hb is above 10 g/dL in CKD patients not receiving dialysis or above 11 g/dL in patients receiving dialysis ESA ο Causes of ESA resistance: ο Fe deficiency ο Inflammation ο βFe delivery to BM response ο AL toxicity ο Folate and vit B 12 Deficiency ο Hyperparathyrodism ο Possibly ACEIs ο Before patient starts EPA following tests should be done: ο RBC indices ο Hct or Hgb ο Reticulocyte count ο Iron parameter ο Occult blood in the stool Peginesatide (withdrawn) ο Peptides that mimic the action of erythropoietin may eliminate the need for recombinant EPO in renal failure. ο Peginesatide is a synthetic peptide that activates the EPO receptor. Peginesatide stimulates erythroid colony growth, reticulocyte count and hematocrit in animal models, but, because its amino acid sequence is unrelated to erythropoietin, does not cross react with erythropoietin antibodies. ο March 2012 ο The US Food and Drug Administration has approved peginesatide for intravenous or subcutaneous administration to treat anemia in adult dialysis patients with CKD but not in CKD patients who are not on dialysis ο February 2013 ο Peginesatide has been withdrawn from the market due to serious hypersensitivity reactions reported in approximately 0.2 percent of patients following the first dose of intravenous administration with death occurring in 0.02 percent of patients. Evaluation of therapeutic outcomes ο Iron status should be assessed at least every 3 months in patients receiving a stable ESA regimen or for those hemodialysis patients not treated with an ESA to detect iron deficiency as a cause for anemia. Iron status should be monitored more frequently (e.g., every month) when initiating or increasing the ESA dose, following a course of IV iron, or when other factors put the patient at risk for iron loss (e.g., bleeding). ο For all ESAs, the initial dose and subsequent adjustments should be determined by the patientβs Hb level and the observed rate of increase in Hb. ο In patients with anemia not treated with an ESA, Hb levels should be monitored at least every 3 months in stage 3 to 5 CKD patients not requiring hemodialysis and at least monthly in hemodialysis patients. ο Hb should be monitored at least monthly (weekly preferred) in patients started on ESA therapy until the Hb is stable. Once Hb is stable, the recommended frequency of monitoring is monthly in dialysis patients and every 3 months in nondialysis CKD patients (see Fig. 29-6). Key points for the management of anemia in CKD patients 1. 2. 3. 4. 5. Work-up for anemia in CKD should include assessment of secondary causes including iron deficiency. Iron replacement is often effective in anemia of CKD as initial therapy and routes of administration (intravenous or oral) will be determined by clinicians, patient preferences, and local available resources. ESA therapy is not recommended in those with active malignancy, or recent history of malignancy. In most people with CKD, ESAs should not be used to intentionally increase the Hb concentration above 11.5 g/dl (115 g/l) For pediatric patients, the selection of Hb concentration at which ESA therapy is initiated should be individualized after taking into account the potential benefits (e.g., improvement in QOL, school attendance/ performance, and avoidance of transfusion) and potential harms. Case: Anemia in CKD Note: Refer to the case in the previous lecture CKD-Mineral and Bone Disorder (MBD) ο CKD-MBD is a systemic disorder of mineral and bone metabolism due to CKD manifested by either one or a combination of the following: ο Abnormalities of calcium, phosphorus, PTH, or vitamin D metabolism ο Abnormalities in bone turnover, mineralization, volume, linear growth, or strength ο Vascular or other soft tissue calcification 6) Secondary Hyperparathyroidism and Renal Osteodystrophy (mineral and bone disorders) ο Calcium and phosphorus homeostasis is mediated through the effects of four hormones on bone, the GI tract, kidney, and parathyroid gland. ο These hormones include PTH, the precursor form of vitamin D known as 25hydroxyvitamin D (25-OHD), active vitamin D or 1,25-dihydroxyvitamin D (calcitriol), and fibroblast growth factor-23 (FGF-23). Homeostatic mechanisms to maintain serum Ca concentration Renal Osteodystrophy Renal osteodystrophy is an alteration of bone morphology in patients with CKD. It is one measure of the skeletal component of the systemic disorder of CKD-MBD that is quantifiable by histomorphometry of bone biopsy. It can be classified as follows: Turnover High Normal Low Mineralization Normal Abnormal Volume High Normal Low Slide courtesy of Susan Ott 2ry Hyperparathyroidism and Renal Osteodystrophy ο As kidney disease progresses renal activation of vitamin D is impaired, which reduces gut absorption of calcium. Low blood calcium concentration stimulates secretion of PTH ο As renal function declines, serum calcium balance can be maintained only at the expense of increased bone resorption, ultimately resulting in renal osteodystrophy. Pathogenesis of 2ry Hyperparathyroidism and Renal Osteodystrophy: Renal Osteodystrophy: ο Secondary hyperparathyrodism can cause complication such as: ο osteitis fibrosa cystica (high bone formation rate - bones turn soft and ο ο ο ο ο ο ο become deformed) Osteomalacia (softening of the bones) adynamic bone disease (under active bone) altered lipid metabolism, altered insulin secretion, resistance to erythropietic therapy, impaired neurological and immune function increased mortality. ο Renal osteodystrophy progresses insidiously for several years before the onset of symptoms such as bone pain and fractures, when symptoms appear, the disease is not easily amenable to treatment. Lab findings and monitoring Corrected calcium (mg/dL) = measured total Ca (mg/dL) + 0.8 (4.0 - serum albumin [g/dL]), There are no substantial differences between KDOQI and KDIGO with regard to recommendations for serum calcium (corrected for serum albumin) and phosphorus. Both KDOQI and KDIGO recommend maintaining serum phosphorus within the normal range for stage 3 to 4 CKD patients and lowering phosphorus toward the normal range for dialysis patients. KDIGO recommends that the corrected serum calcium be maintained within the normal range for all CKD patients; however, KDOQI recommends a more conservative range in stage 5 CKD patients based on an increased risk of soft-tissue and vascular calcifications. The most appropriate strategy is to evaluate trends in corrected calcium to predict if hypercalcemia is a concern that warrants changes in therapy. KDIGO did not specify a particular PTH target, but rather advocated looking at trends in serum PTH to make treatment decisions. Recommended Frequency of Monitoring Calcium, Phosphorus, PTH , and 25 OHD by Stage of CKD (KDIGO Guidelines) CKD Stage Calcium and Phosphorus PTH KDOQI KDIGO KDOQI KDIGO Annually Every 6β12 months Annually Baseline, and If PTH above then based on target level and CKD progression Every 3 months Every 3β6 months Every 3 months Every 6β12 months Monthly Every 1β3 months Every 3 months Every 3β6 months 3 4 5 25-Hydroxyvitamin D KDOQI KDIGO Baseline level; correct deficiencies as in general population Not measured The KDIGO guidelines also recommend monitoring bone-specific alkaline phosphatase annually in stage 4 and 5 CKD patients. The frequency of monitoring these parameters may increase once a diagnosis of CKDMDB is made and further information is needed to assess the patient's response to treatment and to guide decisions about changes in therapy. Monitoring ο In addition to monitoring for biochemical abnormalities that define CKD- MBD, evaluation of bone architecture is also necessary in some cases. ο The gold standard test for diagnosing bone manifestations of CKD-MBD is a bone biopsy for histologic analysis; however, this is an invasive test that is not easily performed. KDOQI and KDIGO guidelines recommend bone biopsy only in patients in whom the etiology of symptoms is not clear or in individuals with more unique biochemical abnormalities. ο This includes patients experiencing unexplained fractures, persistent hypercalcemia, and possible aluminum toxicity. If aluminum concentrations are elevated (60 to 200 mcg/L, a deferoxamine test should be done. ο KDIGO also suggests a bone biopsy be considered in CKD patients prior to beginning treatment with bisphosphonates since adynamic bone disease is a contraindication to the use of these agents. Monitoring ο Bone biopsy findings are described on the basis of turnover rate, mineralization, and volume. ο Bone mineral density testing is not generally recommended in patients with advanced CKD since this test has not been shown to predict fracture risk and does not indicate the type of ROD. Monitoring ο Abnormalities in mineral metabolism are highly associated with vascular and soft-tissue calcifications, known risk factors for mortality; therefore, diagnostic testing for calcifications should be considered in the evaluation for CKD-MBD. ο Electron-beam computed tomography (EBCT) is a noninvasive and sensitive method available for detecting cardiovascular calcifications and has been used clinically and in studies in the CKD population. ο Other methods advocated include: ο lateral abdominal radiographs to detect vascular calcification ο echocardiogram to detect valvular calcification. ο KDIGO suggests these tests are reasonable alternatives to EBCT based on the sensitivity to detect calcifications and lower cost. Management of Renal Osteodystrophy: ο The optimal approach for treating secondary hyperparathyroidism and mineral metabolism abnormalities in predialysis patients with stage 3, 4, and 5 CKD is unclear. ο The current management of secondary hyperparathyroidism in patients with stage 3 to 5 CKD not yet on dialysis principally involves the administration of some combination of: ο dietary phosphate restriction, ο phosphate binders (either calcium or non-calcium containing binders), ο vitamin D analogues, ο calcium supplementation and/or (possibly) ο a calcimimetic (NOT currently approved for patients with CKD not yet undergoing dialysis). 1) Dietary Phosphate Restriction ο In general, serum phosphorus should be lowered toward near normal levels. ο KDIGO recommends normal levels for all stages of CKD, whereas K/DOQI allows a more liberal phosphorus management in stage 5 of 3.5 to 5.5 mg/dL. ο Dietary phosphorus restriction can prevent hyperphosphatemia and maintain target phosphorus concentrations. ο Dietary phosphorus should not exceed 800 to 1,000 mg/day. ο Predominate sources of phosphorus are protein rich foods, which presents a challenge in tailoring a diet that lowers dietary phosphorus intake while providing adequate nutrition. ο However, efforts should be made to distinguish between organic (e.g., plant seeds, nuts, legumes, and meats) and inorganic phosphorus (e.g., preservatives and additive salts found in processed foods) sources. Inorganic phosphorus sources are absorbed to a greater extent than organic phosphorus (90% vs.50%, respectively) and should be minimized in the diet. ο 1) Dietary Phosphate Restriction (contβd) ο Dark carbonated beverages are a common culprit for elevated phosphorus levels; their consumption should be discouraged, and the beverages should be removed from vending machines in dialysis clinics. ο Although phosphorus is removed to some extent by dialysis, neither HD nor PD removes adequate amounts to warrant complete liberalization of phosphorus in the diet (diet phosphate can be increased up to 1200 mg/day) ο Regular dietary counseling by a kidney specialist dietitian is necessary to reinforce the importance of phosphorus restriction and other dietary recommendations. 2) Phosphate Binding Agent: ο A significant reduction of serum phosphorus is difficult to achieve with dietary intervention alone, particularly in patients with more advanced kidney disease (eGFR<30 mL/minute/1.73 m2). ο In these patients, the use of phosphate binding agents is also necessary. ο These agents decrease phosphorus absorption from the gut and should be administered with meals to maximize this effect (A) Oral calcium compounds are first-line agents for controlling both serum phosphorus and calcium concentration, elemental calcium should not exceed 1500 mg/day. ο Correction of hypocalcemia is an added beneficial effect of the calcium-containing preparations; ο Before initiating Ca therapy and during it, the Ca-P product (Ca x P) should be determined. If >55, patient is at risk for Ca deposition in soft tissues and patient should be switched to other binders. ο A βcorrectedβ serum calcium and the βCa-P productβ should be determined before therapy is started and at regular intervals thereafter. (Note: KDIGO guidelines is different β check the next slide) ο Comment on Ca×P product ο Traditionally, the calculated calciumβphosphorus product(Ca×P) value is used as an indication as to when calcium and phosphate may precipitate and deposit into soft tissue, leading to calcific uremic arteriolopathy (CUA). CUA, or calciphylaxis, is characterized by calcification of the arterioles and small arteries with intimal proliferation and endovascular fibrosis and manifests visually as necrosis of the skin. ο K/DOQI guidelines set a target goal of the Ca×P to be less than 55 mg2/dL2, whereas a Ca×P greater than 60 to 70 mg2/dL2 suggests an increased risk of CUA. ο However, KDIGO suggests the Ca×P provides no additional clinical information than the individual values of calcium and phosphorus and is not recommended for guiding therapy. Phosphate-Binding Agents Used for the Treatment of Hyperphosphatemia in CKD Patients Compound Content (mg) 500, 750, 1,000, 1,250 1,250 1,500 667 Dose Titrationa Starting Doses Comments Increase or decrease by 500 mg per meal (200 mg elemental calcium) Sevelamer carbonate Renvela *Available as tablet and powder for oral suspension 800 Increase or decrease by 800 mg per meal 0.5β1 g (elemental calcium) three times a day with meals 0.5β1 g (elemental calcium) three times a day with meals 800β1,600 mg three times a day with meals Sevelamer Hydrochloride Lanthanum carbonate Renagel 400, 800 Fosrenol 500, 750, 1,000 Increase or decrease by 1 tablet per meal Increase or decrease by 750 mg per day Compound Trade Name Calcium carbonate (40% elemental calcium) Tums Oscal-500 Caltrate 600 Calcium acetate (25% elemental calcium) PhosLo Aluminum hydroxide Alterna GEL 600 mg/5 mL Increase or decrease by 667 mg per meal (168 mg elemental calcium) β Same as Renvela 750β1,500 mg daily in divided doses with meals 300β600 mg three times a day with meals First-line agent; dissolution characteristics and phosphate binding may vary from product to product Approximately 39 mg phosphorus bound per 1 g calcium carbonate First-line agent; comparable efficacy to calcium carbonate with half the dose of elemental calcium Approximately 45 mg phosphorus bound per 1 g calcium acetate By prescription only First-line agent; lowers low-density lipoprotein cholesterol More expensive than calcium products; consider in patients at risk for extraskeletal calcification Associated with a lower risk of acidosis and GI adverse events than Renagel. Same as Renvela, plus acidosis First-line agent; Available as chewable tablets Not a first line agent; do not use concurrently with citrate-containing products Reserve for short-term use (4 weeks) in patients with hyperphosphatemia not responding to other binders 3) Vitamine D Therapy: (what are its benefits?) ο Calcium (less than 9.5 mg/dL) and phosphorus (less than 4.6 mg/dL) must be controlled before Vitamin D therapy is initiated. ο Ergocalciferol ο In stage 3 and 4 If the 25-hydryoxyvitamin D level is less than 30 ng/mL, a vitamin D precursor (e.g., ergocalciferol) is recommended ο To prevent vitamin D insufficiency, doses of 600 to 800 units per day of ergocalciferol are recommended ο Calcitriol, (1,25-Dihydroxyvitamine D3) ο Has been used for the management of secondary hyperparathyroidism ο Directly suppresses PTH synthesis and secretion and appears to upregulate vitamin D receptors which ultimately may reduce parathyroid hyperplasia. ο If hypercalcemia develops, the decision to withhold therapy orto switch to a vitamin D analog. ο The comparative effects of the different active oral vitamin D analogs in predialysis patients with CKD have not been established. As a result, any one of the available active oral agents (calcitriol, alfacalcidol, doxercalciferol, or paricalcitol) may be administered. Available Vitamin D Agents Generic Name Trade Name Form of Vitamin D Dosage Range Dosage Forms Frequency of Administration 400β50,000 IU PO Daily (doses of 400β2000 IU) Vitamin D precursor Ergocalciferol Vitamin D2 D2 Cholecalciferol Vitamin D3 D3 Weekly or monthly for higher doses (50,000 IU) Active vitamin D Calcitriol Calcijex 0.5β5 mcg IV Three times per week Rocaltrol 0.25β5 mcg PO Daily, every other day, or three times per week 1β4 mcg PO Daily or three times per week 2.5β15 mcg IV Three times per week 5β20 mcg PO Daily or three times per week 2β8 mcg IV Three times per week Vitamin D analogs Paricalcitol Doxercalciferol Zemplar Hectorol = 1-hydroxyvitamin D2 4) Calcimimetics: ο Acts on Ca-sensing receptor on the surface of chief cell of PT gland to mimic effect of extracellular ionized Ca & increase sensitivity of Ca-sensing receptor to Ca ο decrease PTH secretion within hours after administration. ο The calcimimetic cinacalcet (Sensipar): is the first agent in this class to be approved by the FDA. ο demonstrated efficacy in lowering PTH concentrations and Ca-P product in patients on HD with sHPT and a higher proportion of patients achieved recommended targets for PTH, calcium, phosphorus, and Ca-P product. ο No data are found on survival rates for patients receiving cinacalcet versus those treated with vitamin D. ο Cinacalcet, however, offers an additional choice of agent to lower PTH when vitamin D cannot be increased because of elevated calcium, phosphorus, or calcium-phosphorus product. ο Initiated at a dose of 30 mg daily with dosage titrations occurring every 2 to 4 weeks to 60, 90, 120 or a maximum of 180 mg daily to achieve target iPTH levels. (given with meals) ο Because cinacalcet lowers serum calcium and may cause hypocalcemia, this agent should not be started if the serum calcium is less than the lower limit of normal, approximately 8.4 mg/dL ο Serum calcium and phosphorous levels should be drawn within 1 week after initiation or dosage increase, and plasma PTH levels drawn within 4 weeks after initiation of therapy or dosage adjustment. ο Cinacalcet is metabolized by the liver, specifically by the cytochrome P450 isoenzymes CYP3A4, CYP2D6, and CYP1A2 ο drug interactions ο Cinacalcet is also a potent inhibitor of the enzyme CYP2D6. Stepped approach for the management of renal osteodystrophy Step 1 ο The initial focus in managing sHPT should be the management of hyperphosphatemia. ο Among patients with hyperphosphatemia ο restricting dietary phosphate intake. Step 2 ο Among patients with hyperphosphatemia despite dietary phosphorus restriction after two to four months ο administration of phosphate binders ο For patients with an initial serum calcium levels less than 9.5 mg/dL (<2.37 mmol/L), a calcium containing phosphate binder should be administered as long as hypercalcemia does not develop. ο For patients with an initial serum calcium level greater than 9.5 mg/dL (<2.37 mmol/L), a non-calcium based phosphate binder rather than a calcium-containing phosphate binder. Either sevelamer or lanthanum carbonate can be given in this setting. ο Treatment with ergocalciferol should be initiated if vitamin D deficiency exists, as demonstrated by a 25(OH)-vitamin D (calcidiol) level of less than 30 ng/mL. ο If elevated PTH levels remain despite ergocalciferol and phosphate binder therapy over a six-month period ο administering a low dose active oral vitamin D analog. ο If the serum level of corrected total calcium exceeds 10.2 mg/dL (2.54 mmol/L) ο ergocalciferol therapy and all forms of vitamin D therapy should be discontinued Step 3 ο Decide whether phosphate binder therapy is sufficient or whether a vitamin D analogue should be added. This is based upon calcium, phosphate, and PTH levels that are measured when administering optimal phosphate binder therapy. Step 4 ο Among predialysis patients with sHPT, the use of cinacalcet is controversial. Some experts and the KDIGO working group recommend NOT giving cinacalcet given the paucity of data concerning efficacy and safety in predialysis patients with CKD. Case: Renal Osteodystrophy New! Feb 2017 ο The US Food and Drug Administration (FDA) has approved the novel calcimimetic etelcalcetide (Parsabiv, Amgen) for the treatment of secondary hyperparathyroidism in adults on hemodialysis. ο Etelcalcetide reduces the PTH level by binding to and activating the calcium-sensing receptor on the parathyroid gland. It offers an advantage over the current standard calcimimetic treatment, cinacalcet (Sensipar, Amgen), in that it can be administered intravenously by the dialysis healthcare team at the end of each hemodialysis session. 6) Hyperlipidemia: ο Treatment with a statin should not be initiated in patients with type 2 diabetes on maintenance hemodialysis who do not have a specific cardiovascular indication for treatment (Strong evidence) β see next slide. ο Lipid profile should be reassessed at least annually and 2 to 3 months after changing treatment. ο HMG-CoA reductase inhibitors may have some other advantages that may help to reduce kidney disease progression in addition to lipid reduction, such as: reduction of monocyte infiltration, mesangial cell proliferation, mesangial matrix expansion, and tubulointerstitial inflammation and fibrosis ο New phosphate-binding agent sevelamer hydrochloride appears to lower lipid levels by mechanisms similar to those of bile acid sequestrants. KDIGO ο Management of dyslipidemia in patients with CKD has been guided by recommendations from the National Cholesterol Education Program and the KDOQI guidelines for dyslipidemia. Based on evidence of risk reduction and the benefits of lipid-lowering therapy in the general population, the consensus was that CKD patients should be treated aggressively to an LDL cholesterol goal below 100 mg/dL. ο However, the KDIGO guidelines for lipid management in CKD published in 2013 do not support this goal since clinical trials have not proven the strategy of targeting a specific LDL level to be beneficial. ο KDIGO recommends that a lipid profile be done for all adults with CKD to include LDL, HDL, and triglycerides. Follow up lipid levels are not recommended unless the information may alter management (e.g., assessing adherence to therapy or assessing cardiovascular risk in a patient <50 years of age and not currently on a statin). Patients should also be evaluated for other conditions that are known to cause dyslipidemias (e.g., liver disease). ο KDIGO acknowledges that reduction in the risk of adverse cardiovascular events in patients with CKD has only been demonstrated with regimens that include a statin or statin plus ezetimibe combination and recommendations focus on these agents for individuals at risk of cardiovascular events. KDIGO ο Based on the available evidence, the KDIGO guidelines for lipid management in ο ο ο ο CKD recommend treatment with a statin in adults aged 50 and older with stage 1 to 5 CKD (not on dialysis). The statin/ezetimibe combination may also be an option in patients in this age group in stage 3 to 5 CKD (not on dialysis). KDIGO only recommends statins in adults aged 18 to 49 years with stage 1 to 5 CKD (not on dialysis) who have one or more of the following: known coronary disease, diabetes mellitus, prior ischemic stroke, and an estimated 10year incidence of coronary death or nonfatal myocardial infarction >10%. It is not recommended that statins or statin/ezetimibe be initiated in patients with stage 5 CKD on dialysis; however, therapy with these agents may be continued if patients were receiving these medications at the time of dialysis initiation. Due to the risk of adverse events with statins and absence of safety data in patients with stage 3 to 5 CKD, KDIGO recommends using statins at doses shown to be beneficial in randomized studies conducted in this population (e.g., atorvastatin 20 mg, fluvastatin 80 mg, rosuvastatin 10 mg, simvastatin 20 mg). ο Atorvastatin treatment in patients with type 2 diabetes on maintenance hemodialysis treatment does not improve cardiovascular outcomes. (Strong evidence) ο Results from a 4-year study evaluating the effect of atorvastatin therapy on cardiac mortality in more than 1,200 hemodialysis patients with type 2 diabetes showed no significant benefit in the composite end point compared with the placebo group. 124 In fact, there was a significantly greater relative risk of fatal stroke in the atorvastatin-treated patients. These findings do not support initiation of statin therapy in ESRD patients, especially those with type 2 diabetes Avoiding agents that increase the blood levels of statins ο A number of medications may interact with the metabolism of statins and thereby increase statin blood levels. ο Medications known to increase statin blood levels should either be avoided, or, if necessary, the statin should be reduced or stopped. ο While this is true for all patients, it is especially true for patients with CKD Stages 4-5, since some statin levels tend to be high in Stage 4-5 CKD patients. ο It is even more critical for interactions to be avoided among kidney transplant patients receiving cyclosporine (and possibly tacrolimus), since cyclosporine often increases statin levels through mechanisms that may be exacerbated by the addition of a third interacting agent. 7) Hypertension: ο The pathogenesis of hypertension in patient with CKD is multifactorial. 8) Anorexia & Malnutrition ο Limited data defining CKD stage where malnutrition develops ο Malnutrition is common in patients with advanced chronic renal disease because of: a lower food intake (principally due to anorexia), decreased intestinal absorption and digestion, and metabolic acidosis ο Studies have shown a strong correlation between malnutrition and death in maintenance dialysis patients ο It is desirable to monitor the nutritional status of patients with chronic kidney disease. NKF K/DOQI guidelines: evaluate for signs of malnutrition when GFR < 60 mL/min/1.73 m2 ο A low plasma concentration of albumin and/or creatinine (which varies with muscle mass as well as GFR) may be indicative of malnutrition. ο Nutrition assessment ο dietary protein ο calorie intake ο serum albumin ο urine protein Malnutrition: ο Protein-energy malnutrition is common in patients with stage 4 or ο ο ο ο 5 CKD Daily protein intake should be 1.2g/kg for patient undergoing hemodialysis and 1.2 to 1.3 g/kg for those undergoing peritoneal dialysis Daily energy intake should be 35 kcal/kg for patients undergoing any type of dialysis ,the intake should be lowered to 3035 kcal/kg for patients older than 60 years. Water-soluble vitamins should be supplemented to replace dialysis-induced loss L-carnitine is not recommended for patients with ESKD unless the disorders for which it has shown benefit (eg: hpertriglyceridemia, hypercholesterimia, and anemia) do not respond to standard therapies. 9) Other complications Self reading: ο Management of other complications: ο Uremic bleeding ο Pericarditis ο Uremic neuropathy ο Thyroid dysfunction ο Reference: UpToDate: ο Overview of the management of chronic kidney disease in adults Prescribing in people with CKD Prescribing in people with CKD