Treatment of CKD-related Hyperparathyroidism Flashcards
What do oral phosphate binders do?
Lower plasma phosphate levels
In CKD phosphate elimination is dec. so phosphate is elevated
How does the high phosphate levels related to CKD lead to hyperparathyroidism?
Elevated phosphate levels lead to a decrease in plasma Ca++ levels that can lead to hyperparathyroidism
Why is the oral phosphate binder Aluminum hydroxide rarely used?
It can causes aluminum toxicity
How do the oral phosphate binders calcium carbonate and calcium acetate work and which one is more effective?
Binds to dietary phosphate inhibiting absorption
Calcium acetate is most effective
When should calcium carbonate and calcium acetate be dosed?
With meals
AE of calcium carbonate and calcium acetate:
Iatrogenic hypercalcemia and increased risk of vascular calcifications
Monitor Ca levels regularly
(Useful in patients with hypocalcemia)
When is the risk of hypercalcemia while taking calcium carbonate and calcium acetate increased?
When taking vit D
What is the advantage of using the oral phosphate binder Sevelamer (Renagel, Renvela):
Binds dietary phosphate inhibiting absorption and contains no aluminum or calcium
Why is Sevelamer carbonate (Revela) used over Sevelamer HCl (Renagel)?
Renvela is the buffered for the drug and does not causes metabolic acidosis like Renagel can
Which type of patients might Sevelamer (Renagel, Renvela) be good for?
Patients with hypercalcemia
May also decreased cholesterol absorption by binding bile acids
What is Lanthanum carbonate (Fosrenal)
Oral phosphate binder derived from rare earth metal
Contains neither aluminum or calcium
Useful in patients with hypercalcemia
_______ vit D synthesis can lead to hyperparathyroidism
Impaired
How dose administration of active vit D affect PTH levels?
Lower PTH levels
CKD can decrease the activation of vit D, therefore agents that are administered must:
bypass the need for activation in the kidney
Calcitrol, Paricalcitrol, and doxecalciferol are examples of:
Vit D (calcitrol) and vit D analogues
Where is Doxecalciferol activated to vit D?
Liver
Calcimimetics such as Cinacalcet (Sensipar) MOA:
Binds to Ca sensing rc
Increases sensitivity to Ca
Rc’s are activated at lower Ca levels which suppresses PTH synthesis and secretion
Calcimimetics are used to treat what in addition to CKD related hyperparathyroidism?
Hypercalcemia associated with parathyroid carcinoma
When is IV calcium used and what kinds?
Severe hypocalcemia
Gluconate and chloride
Oral Calcium used to treat hypoparathyroidism and osteoporosis include:
Calcium citrate:most absorbed form
Calcium carbonate: low cost, antacid, absorption better with food and in acidic environment (dec absorption with H2 antag and PPIs)
AE of Calcium administration:
Constipation, kidney stones
Why are cholecalciferol (vit D3-sun) and ergocalciferol (vit D2-diet) ineffective in CKD?
Both forms still need to be converted to their active form
What are cholecalciferol (vit D3-sun) and ergocalciferol (vit D2-diet) used to treat?
Hypoparathyroidism
Rickets
Osteomalacia
Osteoporosis
In treatment and prevention of osteoporosis with vit D what else is used?
Calcium to increase calcium absorption
