Renal: Lecture 4 Flashcards
Potential CKD Complications
Anemia CVD Infection Acidosis (Dec pH) Mineral & bone Disorder Fluid and Electrolyte Disturbance
Common complications of Stage 4/5 CKD
CKD Mineral bone disorder
Renal osteodystrophy
Anemia of CKD
CKD-MBD biochemical abnormalities
Alterations in serum phosphorus, ca, PTH, and 25(OH)D (inactive form)
Reduced renal mass causes…
reduced serum natural and active Vitamin D
Reduced serum calcium
Increased serum phosphate
Increased serum PTH
Vascular calcification leads to….
CVD
Bone disease leads to….
Fracture risk
several hormones regulate calcium-phosphate homeostasis…..
PTH
25-OHD (inactive Vit D)
Active Vit D
Clinical presentation CKD-MBD lab values
Dec Ca, Vit D levels, Bone mineral Density
Inc: Phosphate, Ca/Phos product, PTH
Might see fractures
CKD-MBD Screening KDIGO recommendation
all patients with GFR <45 are eval yearly (Stage 3a)
Calculating Calcium Phosphate product
Corrected Calcium: Ca + ((0.8*(4-albumin))
CaPhos product: Corrected Ca Phosphate
What should Ca*Phosphate product be below?
Below 55, >70 you get calcifications
“high Lvls of PTH”
150/200 etc going up
CKD-MBD General approach to treatment
1st line = dietary phosphate restriction (800-1000mg/day)
2nd line = phosphate binders
Options for CKD-MBD Pharmacologic Treatments
Phosphate binding agents
Vit D Therapy
Calcimimemtics
Phosphate binders MOA:
Bind to phosphate in GI to reduce absorption of phosphorus (Take w/ Food, usually 3 X day)
Goal: Reduce the Ca*Phos product
KDIGO 2017 guidelines
Non-calcium containing phosphate binders preferred
For all phosphate binders, lowest dose that is effective should be used
What to watch out for if calcium-containing binders are used….
total dose of elemental calcium should not exceed 2000mg per day.
amount of elemental calcium contained in binder should not exceed 1500mg/day
Phosphate Binders
Calcium Carbonate (TUMS): Cheap, but 40% elemental Ca
Calcium Acetate (PhosLo): 25% elemental Ca
Sevelamer Carbonate (Renvela) Lanthanum Carbonate (Fosrenol)
Which one is less dependent on stomach acid? Calcium Carbonate or Acetate
Calcium Acetate
Calcium Carbonate vs Acetate
Carbonate: OTC, Cheaper, relies on stomach acid
Acetate: RX, relies less on acid, less ca
Sevelamer Carbonate (Renvela)
non calcium containing
Expensive, more expensive than calcium products
Lanthanum Carbonate (Fosrenol)
Not really used
Available as chewable tablets
Aluminum Hydroxide
Reserved for short term use in pt not responding to binders or other treatments
2-3 days up to month
Phosphate Binders Side effects
Gi upset
Nausea
Bloating
Constipation
Counseling points phosphate binders
Taking with food is critical
Separate meds with DDI potential by 1hr before or 3 hr after ie Quinolones
Drugs used to suppress PTH
Vitamin D Therapy
Vitamin D Analogs
Calcimimetics
Prior to initiation of Vitamin D therapy, important to control….
Ca and Phos as therapy will result in increase of both….increasing the product
Treatment of Hyperparathyroidism
(CKD Stage 1-4) If inactive lvl Vit D <30ng/ml, and PTH is at goal then….
Tx w/ oral Vit D precursors is recommended
Treatment of Hyperparathyroidism
(CKD Stage 1-4) If inactive lvl Vit D >30ng/ml, but PTH not at goal then….
Tx w/ activated Vit D recommended
Treatment of Hyperparathyroidism
For CKD Stage 5, treatment with activated Vit D is….
recommended
Calcimimetics are used for patients who are on…
Dialysis and PTH is uncontrolled with phosphate binders and Vit D
Can lead to Hypocalcemia
Inactive forms of Vitamin D
Ergocalciferol (D2)
Cholecalciferol (D3)
Activated form of Vitamin D
Calcitriol
Paricalcitol and Doxercalciferol (analogs)
Benefit of Vitamin D analogs
More specific at PTH gland so less GI side effect but more $$
Hypercalcemia and hyperphosphatemia are most pronounced with which activated Vitamin D
calcitriol
Least pronounced with paracalcitol
Oral Vitamin D
Ergocalciferol (D2)
Cholecalciferol (D3)
Calcitriol (Both PO and IV)
Benefit of having IV version of Vitamin D
billed to part B
Mixed in with other IV meds receiving
Peritoneal Dialysis
Can be done at home, through peritoneum
Don’t have to go Dialysis unit like with Hemodialysis (Blood)
Oral med preferred when…
Peritoneal or no Dialysis
IV med preferred when….
Hemodialysis
vitamin D pre-cursors only effective in patients with….
Low Vitamin D levels in Stage 1-4 CKD
Use Activated Vitamin D or analogs right away in…
Patients with Stage 5 CKD
Cinacalcet (Sensipar)
Calcimimetics
**Only used in Stage 5 CKD, Dialysis pt
Usually use 90mg/day, max 180mg/day
Calcimimetics Drug interactions
Have a lot of interactions with Cyp
TAKE WITH FOOD, inc absorption 81%
**Hypocalcemia Side effect
What to monitor in CKD-MBD treatment
Calcium Phosphate Ca*Phos Product Vitamin D lvl Bone Density
How does Anemia occur in CKD
Reduced production of Erythropoietin Hormone
GI absorption of iron impaired
Anemia Symptoms Stages 3/4/5 CKD
Fatigue, weakness, SOB
Dec Hct, Hgb
Who should be screened for anemia w/ CKD
males w/ Hgb <13
females w/ Hgb <12
What should initial anemia workout include
* Most important* Hct,Hgb Iron Indices (Tsat and ferritin)
TSAT is
Transferrin saturation, content of hemoglobin in the reticulocytes
Calc: (Serum iron/TIBC) X 100
Absolute iron deficiency is diagnosed when….
Tsat <20%
Ferritin <100ng/ml (Predialysis and peritoneal dialysis), <200 hemodialysis patient
Goals for Lab markers in Anemia of CKD
Hemoglobin = 10-11.5g/dL
Tsat >20-30%
Ferritin >100-200(KDOQI), >500 (KDIGO)
General Approach to treatment of Anemia of CKD
increase Oxygen carrying capacity, decreasing dyspnea,orthopnea,fatigue
Prevent long term consequences of LVH and CV mortality
Pharmacologic Treatment of Anemia of CKD
Step 1: Iron
Step 2: ESA (Eryhtropoietin stimulating agents)
non pharmacological treatment of Anemia of CKD
Maintain adequate dietary iron intake, most pt require supplement
Make sure pts supplements with water-soluble multivitamin as they can be removed by dialysis
Indications for Iron in Anemia of CKD
TSAT <30% and Ferritin <500
Oral vs IV Iron
IV iron used usually at “absolute deficiency”
Oral used for “functional deficiency”, above TSAT 20%, Ferritin >200
Oral Iron recommendations
200mg elemental/day
goal: give on empty stomach but causes GI issues. Most take w/ food
Give with some sort of stool softener/laxative
Preferred Iron product
Ferrous Sulfate
IV iron
Skips the GI side effects
Better for those on dialysis
Ferric Gluconate (Ferrlecit)
Dialysis:125 mg over 8 sessions
Non-Dialysis: 250mg once a week for 3-4 doses
Iron Sucrose (Venofer)
Dialysis: 100mg for 10 sessions
Non-Dialysis: 200mg times 5 over a 2 week period
Ferumoxytol (Feraheme)
All pts: 510 mg as single dose followed by second 3-8 days later
$$$
Drugs/Food interactions that decrease oral iron absorption
Calcium containing products decrease
iron decrease quinolone absorption
Acid suppressive therapy decrease iron absorption, can be improved with admin of ascorbic acid
IV iron Adverse effects and DDI
No DDI
Well tolerated, aside from Iron Dextran
ESA important info
not recommended to be initiated in patients with Hg > 10g/dL
Make sure no bleeding
All preventable causes should be corrected
when not to use ESA
patients with certain tumor types (Solid organ tumors), they shorten overall survival and or increased risk of tumor progression or recurrence in some clinical studies
Used very selectively
ESA are generally initiated in patients with….
no contraindications
Hgb <10, TSAT >25% and ferritin >200
Hgb target is 10-11.5
ESA admin in non-Hemodialysis patients
SubCu is preferred
ESA admin in Hemodialysis patients
SubCu is desirable, but most given IV due to ins billing
Erythropoietin alpha (Epogen, Procrit)
Dosed in units
SC doses = 1/3 IV, longer T1/2
Darbepoetin alpha (Aranesp)
Dosed in mcg/kg
Erythropoietin alpha (Epogen, Procrit) dosing
Non-HD: 50-100 units/kg IV or SC once weekly or every 2 weeks
HD: 50-100 units/kg IV or SC 1-3 times per week
Don’t change doses more frequently than every 3-4 weeks, increments of 25%
Darbepoetin alpha (Aranesp) dosing
Non-HD: 0.45 mcg/kg IV or SC once every 4 weeks
HD: 0.45 mcg/kg IV or SC once per week or 0.75mcg/kg every 2 weeks
** Don’t change dose more frequently than once per month, increments of 25%***
Why should you wait to increase doses of ESAs
Takes time to make red blood cells
Takes few weeks to see results in Hgb
What should you monitor when giving ESAs
Hgb
TSAT
Serum Ferritin
