CKD - MBD

Question 1

How P is affected

Answer 1

kidneys cannot clear P and it accumulates in the blood, so the readings increase

Question 2

How is vitamin D affected in CKD

Answer 2

• kidneys cannot produce enzyme to convert inactive vitamin D to vitamin D
• vitamin D decreases

Question 3

How is Ca affected

Answer 3

• vit D receptors in the gut facilitate absorption of Ca –> As vit D decrease, Ca decreases too
• P also binds to Ca ‒> as P increases, free Ca decrease

Question 4

How PTH is affected in MBD

Answer 4

PTH levels increase because of high P and low Ca

results in bone diease, erythropoeitin resistance

Question 5

Corrected Ca equation in CKD

Answer 5

Corrected Ca = measured Ca in mmol/L + [0.02 x (40 – serum albumin in g/L)]

Question 6

Phosphate control (non pharm)

Answer 6

limit dietary P intake to 800-1000mg/day

avoid protein, vegetables (have moderate P), preservatives, dairy, chocolate, cola, grain/wheat products –> switch to white bread/white rice

Question 7

list the types of P binders

Answer 7

• Ca salts
  
  • CaCO3
  • Ca acetate
• non Ca (Sevelamer),
• Lanthanum,
• Al based,
• sucroferric oxyhydroxide (Fe based)

Question 8

SE of Ca based P binders

Answer 8

hypercalcemia, constipation, loss of appetite,
nausea, vomiting

hypercalcemia bc increased risk of Ca absorption esp in vit D therapy
its also ineffective as a Ca replacement when given alone

Question 9

SE of sevelamer

Answer 9

constipation, diarrhea, flatulence, indigestion, N/V

tablet also needs to be swallowed whole so thats unslay
and $$$

Question 10

SE of lanthanum

Answer 10

abdominal pain, diarrhea, nausea, vomiting,

$$$ but its a chewable tablet tho

Question 11

SE of aluminium P binders

Answer 11

• GI – constipation, diarrhea, GI obstruction
• Phosphate depletion (weakness, mental status changes)
• Aluminum toxicity – dementia, encephalopathy, worsening
  anemia, osteomalacia, adynamic bone disease

Used in severe hyperphosphatemia (P > 2.2 mmol/L)
uncontrolled by other binders
Due to risk of toxicity, not recommended to use for > 4 wks

Question 12

SE of sucroferric oxyhydroxide

Answer 12

Nausea, diarrhea, stool
discoloration, flatulence

but its non Ca, non Al and its chewable
contains iron but not much iron absorption if taken properly, so it doesnt help iron deficiency

Question 13

patient education on P binders

Answer 13

• pls eat WITH meals and snack
• take 2-3h apart from other drugs –> DDI (P binders may prevent absorption of drugs)
• chewed vs whole tablet
• just dont eat phosphate

• eat a few mouth then eat p binder then eat the rest of the meal
• if u eat before meal, it may cause early satiety
• esp P based drugs eg digoxin, quinolones, warfarin

Question 14

whats used for vit D deficiency

Answer 14

• calcitriol (active D3)
• Alfacalcidol (synthetic incative vit D)

Question 15

Dosage form of Calcitriol

Answer 15

oral only

Question 16

Dosage form of Alfacalcidol

Answer 16

• PO oral capsules, solution
• IV (2mcg/ml)

it also requires activation by 25 - hydroxylase in the liver so pt needs adequate liver function

Question 17

Names of calcimimetics

Answer 17

• cinnacalcet
• Etecalcetide

Question 18

SE of cinnacelcet

Answer 18

nausea, vomiting, diarrhea, hypocalcemia (seizures, tetany, muscle cramps)

Question 19

monitoring of cinnacalcet

Answer 19

• Monitor serum Ca once/week during initiation and dose titration, and every 2 weeks during maintenance
• Monitor PTH 2x/month during initiation and dose titration, and once/month during once PTH is stable

Question 20

SE of etecalcetide

Answer 20

Nausea, vomiting, diarrhea, hypocalcemia (seizures, QTc prolongation)

Question 21

Monitoring of etecalcetide

Answer 21

• Monitor: serum Ca within 1 week of initiation/dose adjustment, every 4 weeks after;
• PTH after 4 weeks from initiation/dose adjustment, every 1-3 months thereafter
• initiate etelcalcetide 7 days after last cinacalcet dose (serum Ca must be within normal range)