"Pharmacology Parathyroid Jennifer Kelly" Flashcards
What states promote the reabsorption of phosphate?
Phosphate depletion
Hypocalcemia
Hypoparathyroidism
What states promote the excretion of phosphate?
PTH PTHrP Hypercalcemia Hypokalemia Hypomagnesemia Calcitonin Glucocorticoids Diuretics
What drugs inhibit magnesium reabsorption in the Loop of Henle?
Furosemide
Cisplatin
How does vitamin D work to maintain calcium homeostasis?
Increases intestinal absorption of dietary calcium and stimulating bone cells to become osteoclasts
What are the most common causes of hypercalcemia?
Hyperparathyroidism
Malignancy
Why can granulomatous diseases such as sarcoidosis cause hypercalcemia?
These diseases increase the conversion of active vitamin D (25–>1,25) which increases osteoclast activity.
What is the most common cause of primary hyperparathyroidism?
Benign, solitary adenoma
What labwork is commonly found in primary hyperparathyroidism?
High or normal PTH
Elevated urine calcium
Elevated serum calcium
Low phosphorous (may see)
Class: Cinacalcet
Calcimimetic
MOA: Cinacalcet
Reduces PTH and serum calcium levels (alters function of calcium receptor)
Uses: Cinacalcet
Secondary hyperparathyroidism from renal disease; parathyroid carcinoma;
hypercalcemia in primary hyperparathyroidism not treatable by surgery
Side effects: Cinacalcet
Vision changes, palpitations, dizziness, chest pains, headache
What is milk alkali syndrome?
Excessive use of OTC calcium such as Tums
Lithium can have what effects on calcium levels?
Lithium can increase PTH levels and increase parathyroid gland mass
Thiazides have what effect on calcium?
They increase serum calcium by lowering excretion
Class: Pamidronate
Bisphosphonate
MOA: Pamidronate
Reduce osteoclastic bone resorption
Uses: Pamidronate
Hypercalcemia of malignancy;
Paget’s disease of bone;
prevention of fractures in osteogenesis imperfecta
Side effects: Pamidronate
Fever
Flu-like symptoms
Class: Zoledronic acid
Bisphosphonate
MOA: Zoledronic acid
Reduce osteoclastic bone resorption
Uses: Zoledronic acid
Hypercalcemia of malignancy;
Paget’s disease of bone;
prevention of fractures in osteogenesis imperfecta
Side effects: Zoledronic acid
Fever
Flu-like symptoms
How are bisphosphonates administered?
IV, so bypasses GI tract
Takes several days to lower serum calcium
How do you prevent volume overload and promote calcium excretion in the treatment of hypercalcemia?
Give a loop diuretic such as fursemide, bumetanide, torsemide, ethacrynic acid
How does renal disease cause secondary hyperparathyroidism?
Phosphate retention, and lack of 1-alpha hydroxylase activity in the failing kidney, resulting in a 1,25 deficiency. At high concentrations, phosphate directly stimulates PTH secretion
How is parathyroidism secondary to renal disease treated?
Low phosphate diet
Phosphate binders
vitamin D supplementation
Dialysis
What is tertiary hypoparathyroidism?
Parathyroid glands become autonomous after prolonged secondary parathyroidism
Gland ends up oversecreting, so patients resemble those with primary parathyroidism
Serum calcium is high
In what endocrinologic condition would you see a prolonged QT interval?
Hypocalcemia
A shortened QT interval would be seen in hypercalcemia
Class:
Calcitriol;
Paracalcitol;
Doxercalciferol
Vitamin D analogs
MOA: Calcitriol;
Paracalcitol;
Doxercalciferol
Binds to VDR and elevates serum calcium levels
Uses: Calcitriol;
Paracalcitol;
Doxercalciferol
Secondary hyperparathyroidism from renal disease
