CKD + Bone Mineral Disease (Exam 1 Cut Off) Flashcards
Goals of Therapy
- Prevent secondary hyperparathyroidism
- Prevent CKD BMD: bone pain, bone fractures, bone deformities
- Prevent soft tissue calcification
- Prevent morbidity and mortality associated with sHPT and CKD-MBD
Managing CKD-MBD
- Lowering high serum phosphorus and maintaining serum calcium
- Treating abnormal PTH levels
Lab Reference Values - BMD
- P: 2.3-5.6 mg/dL
- Ca: 8.4-10.4 mg/dL
- PTH: 18-84 pg/mL
What do you assess first?
Phosphorus
Limit/Avoid high phosphorus foods
Guidelines for CKD 3a-5
- Treatment should be based on serial assessments of phosphate, calcium, and PTH levels (consider TOGETHER)
- We suggest lowering elevated phosphate levels toward the normal range and treat overt hyperphosphatemia
CKD 3a/b Monitoring/Goals
Serum Ca
- Monitor: Every 6-12 months
- Goal: Maintain within normal range
Serum Phosphorus
- Monitor: Every 6-12 months
- Goal: Maintain within normal range
Intact PTH
- Monitor based on baseline level and CKD progression
- Goal: normal range
CKD 4 Monitoring and Goals
Serum Ca
- Monitor: Every 3-6 months
- Goal: Maintain within normal range
Serum Phosphorus
- Monitor: Every 3-6 months
- Goal: Maintain within normal range
Intact PTH
- Monitor: every 6-12 months
- Goal: normal range
CKD 5ND Monitoring and Goals
Serum Ca
- Monitor: Every 1-3 months
- Goal: Maintain within normal range
Serum Phosphorus
- Monitor: Every 1-3 months
- Goal: Maintain within normal range
Intact PTH
- Monitor: every 306 months
- Goal: normal range
CKD 5D Monitoring and Goals
Serum Ca
- Monitor: Every 1-3 months
- Goal: Maintain within normal range
Serum Phosphorus
- Monitor: Every 1-3 months
- Goal: Maintain towards normal range
Intact PTH
- Monitor: every 3-6 months
- Goal: 2-9 times the upper limit of normal
Phosphate Binders
- Prevents absorption of phosphorus from the diet
- Only for the gut
- Administer with meals
Calcium Salt Options
- Calcium Carbonate
- Calcium Acetate
- Calcium Citrate
Calcium Carbonate
- OsCal, Tums, etc.
- 40% elemental calcium
- Inexpensive, OTC
- Wide variety of products/availability
Calcium Acetate
- PhosLo 667 mg
- 25% elemental calcium
- Expensive, Rx only
- Similar phosphorus binding efficacy as calcium carbonate
- First line agent for hyperphosphotemia
Calcium Citrate
- AVOID
- Thought to increase Al absorption: Al toxicity
Calcium Salt AE/Initial Dosing
AE
- Constipation
- HYPERCALCEMIA
Initial Dose
- 250-500 mg of elemental Ca TID with meals
- Titrate to serum phosphorus concentrations
Calcium Salt Guideline Recommendations
- We suggest avoiding with hypercalcemia
- Restrict dose of calcium-based phosphate binders
- Limit elemental calcium from binders to 1500 mg/day
[Calcium] + Hypoalbuminemic
- Total serum calcium concentration corrected for low serum albumin
- Better reflection of free [Ca]
- Corrected CA = Measured + 0.8*[4-serum albumin]
- *If serum albumin >4, don’t correct the calcium level**
Sevelamer
- Renvela
- Nonadsorbed phosphate-binding polymer: anion-exchange resin
- Free of metal ions
- Decreases TC and LDL by 15-30%
- Formulations: 800 mg tablets or 800/2400mg powder packets
Sevelamer AE
- N/V
- Diarrhea
- Dyspepsia
- Bowel Obstruction
Sevelamer Dosing
- Start at 800-1600 mg TID with meals depending on severity of hyperphosphatemia
- Titrate dose up or down based on effect
Sevelamer Place in Therapy
- First line, more expensive than calcium salts
- Preferred for those with hypercalcemia or extraskeletal calcification
- For patients who remain hyperphosphatemic on monotherapy, use combo therapy
Fosrenol
- Lanthanum Carbonate
- 500, 750, 1000 mg chewable tablets
- AE: N/V, abdominal pain
- Dosing: 500 mg PO TID with meals
- Costly
- Consider when hypercalcemia is an issue
- No long-term safety data and limited drug interaction information
Aluminum Salt
- Aluminum hydroxide
- Alternagel: 600 mg/5 mL susp
- Amphojel: 300/600 mg tablet, 320 mg/5 mL suspension
- High phosphate binding toicity
- AE: aluminum toxicity, constipation/impaction
- Dose: 300-600 mg PO TID with meals
Guidelines + Aluminum Salt
- AVOID LONG TERM USE
- Limit to 4 weeks only
Aluminum Disease
- Dementia/neurotoxicity
- Anemia
- Renal osteodystrophy
Iron Salts Options
- Sucroferric Oxyhydroxide
- Ferric Citrate
Velphoro
- Sucroferric oxyhydroxide
- Dose: 1 tab chewed TID with meals (max of 6 tabs/day)
- ADE: diarrhea, discolored feces, nausea
- Available: 500 mg chewable iron tablet
Auryxia
- Ferric Citrate
- Dose: 2 tabs TID with meals (max 12 tabs/day
- ADE: diarrhea, constipation, nausea, discolored feces
- Available: tablet containing 210 mg iron
Phosphate Binders: Drug Interactions
- Ca, Al, Lanthanum, Sevelamer, Fe
- Interfere with absorption with other drugs like quinolones, levothyroxine
- Known interaction with Ca salts and PO iron
- Space administration timing with all of the above
Guidelines + Abnormal PTH Levels
- Optimal PTH levels are not known for 3a-5
- However, if their lab values are rising or persistently above upper normal limit, assess for modifiable factors
- Factors include hyperphosphatemia, hypocalcemia, high phosphate intake, and vitamin D deficiency
Vitamin D Indications/AE
- Indication: enahnce Ca+ and P+ absorption from the gut
- AE: hyperphosphatemia and hypercalcemia
Inactive Vitamin D
- Ergocalciferol (D2) and Cholecalciferol (D3)
- If CKD 3/4 + Elevated iPTH, measure vitamin D level: give inactive Vitamin D if < 30 ng/mL
- Stage 4 CKD + Elevated iPTH: measure vitamin D level: give active Vitamin D if > 30 ng/mL
Vitamin D Dosing
- Vitamin D < 5 ng/dL: severe deficiency requiring 50,000 IU/week PO x 12 weeks, then qmo x 6 mo
- Vitamin D 5-15 ng/dL: mimld deficiency, 50,000 IU/week PO x 4 weeks, then qmo x 6 mo
- Vitamin D 16-30 ng/dL, vitamin D insufficiency requiring 50,000 IU/mo PO x 6 mo
Cholecalciferol
- No dosing recommendations for guideline
- Clinic Example: 1000 IU PO daily
- Titrate to 4000 IU PO daily as required to replenish vitamin D stores and decrease iPTH
Guidelines + Active Vitamin D/Analogs
- Dont use for 3a-5ND routinely
- Reserve calcitriol and vitamin D analogs for CKD 4-5 patients with severe/progressive hyperparathyroidism
Active Vitamin D
- Calcitriol
- Most active form
- PO: 0.25 or 0.5 ug capsule
- 1 ug/mL solution
- IV form: Calcijex
- Risk of hypercalcemia and hyperphosphatemia
- Daily or TID weekly dosing
Paricalcitol
- Zemplar
- Vitamin D Analog
- 1, 2, and 4 ug capsules or IV form
- 19-nor-1,25-dihydroxyvitamin D2
- Associated with decreased incidence of hypercalcemia and hyperphosphatemia than calcitriol
Doxercalciferol
- Hectorol
- Vitamin D Analog
- 1-alpha-hydroxyvitamin D2
- 0.5, 1, and 2.5 ug capsules and IV form
- Associated with decreased incidence of hypercalcemia and hyperphosphatemia than calcitriol
Calcifediol
- Rayaldee
- Vitamin D Analog
- 25-hydroxyvitamin D3
- ER 30 mcg cap
- Indicated for CKD 3 or 4 with vitamin D levels <30 ng/mL
- Monitor for hypercalcemia and hyperphosphotemia
Guidelines + PTH in Dialysis
- Maintain iPTH levels in the hrange of approximately 2-9 times the upper limit of normal
- In patients with CKD 5D requiring PTH lowering therapy, use calcimimetics, calcitriol, or vitamin D analogs, or a combination of both
Cinacalcet MoA
- Cinacalcet bind to the CaR and increases its sensitivity to Ca
- When Ca binds to CaR, the receptor is activated
- PTH release is inhibited
Cinacalcet
- Calcimimetic
- 30, 60, 90 mg tablets
- Dose: 30-180 mg daily with meals
- Useful in patients with high calcium and/or phosphate levels with elevated iPTH
Cincalcet AE
- Hypocalcemia: avoid if Ca <8.4 mg/dL
- Paresthesia, myalgias, cramping, seizures
- GI: N/V, diarrhea
Cincalcet Drug Interactions
- Inhibits CYP 2D6 (antiarrhythmics, psych meds)
- CYP 3A4 substrate
Cinacalcet Monitoring
- Serum Ca and P within 1 week of starting/changing dose
- iPTH within 1-4 weeks of starting/changing dose
- If Ca decreases under 7.5 mg/dL or patient is symptomatic, HOLD cincacalcet and restart a lower dose when Ca > 8 mg/dL
- If Ca 7.5-8.4 mg/dL, start Ca-based phosphate binder or vitamin D (if appropriate)
Managing Therapy for Renal Osteohystrophy and sHPT: Step 1
- Assess for hyperphosphatemia: if present, initiate phosphate binder (Ca based or sevelamer) and monitor calcium levels to avoid hypercalcemia
- *Use corrected calcium formula**
- Can use combinations
Managing Therapy for Renal Osteohystrophy and sHPT: Step 2
- Consider Vitamin D
- Stage 3/4 with elevated iPTH: inactive if vitamin D, 30 ng/mL
- Stage 4 + elevated iPTH + Vit. D > 30 ng/dL: use active vitamin D or analog
- Stage 5 + elevated iPTH: active vitamin D or Vitamin D analog
- Ensure Ca and P well controlled before starting
- HOLD all forms of vit. D when corrected Ca levels are elevated
Managing Therapy for Renal Osteohystrophy and sHPT: Step 3
- Assess need for calcimimetic
- Only Stage 5D