Parathyroid diseases Flashcards
What is the function of the parathyroid?
Secrete parathyroid hormone
What does low calcium do?
-Increase PTH
What regulates PTH release?
-Free calcium in the blood
What does PTH activate?
-Osteoclasts and bone resorption to increase serum calcium
What can excessive release of PTH cause?
-Osteoporosis
Besides osteoclasts and bone resorption what else does PTH do?
- Activate Vitamin D
- Increase GI absorption
- Increase tubular reabsorption of calcium
What can cause hypercalcemia?
- Tumor
- Primary hyperparathyroidism
What is secondary hyperparathyroidism?
-Intestinal malabsorption of vitamin D or calcium
Primary hyperparathyroidisms are mostly what?
Adenomas
What are the symptoms of primary hyperparathyroidism?
-Osteoporosis (Fractures)
-Increased systemic levels of calcium causing constipation
-nonspecific weakness
-anorexia
-Stones
-Peptic ulcers
-Depression
-Cystic bone lesions
“Bones, stones, groans, and moans”
What heart condition can be associated with primary hyperparathyroidism?
-Arrhthmias
What lab findings do you see with primary hyperparathyroidism?
-Elevated serum Ca++
-Hypophosphatemic
(Remember Ca++ and phosphates often go in opposite directions)
-High or normal PTH
What is Denosumab (XGEVA)?
- Treatment for osteoporosis
- Antibody to the osteoclastic-stimulationg protein (RANK)
- Ultimately blocks osteoclast number and activity
What is Teraparatide (Forteo)?
- Treatment for osteoporosis
- A recombinant form of parathormone segment which selectively activates osteoblasts and stimulates new bone formation
What do estrogens or estrogen modulators do for osteoporosis?
-Prevent bone loss early in postmenopausal period
What should estrogens be used in combination with in postmenopausal women?
-Progestin to protect against venous thrombi
What are bisphosphonates used to treat osteoporosis?
- Ibandronate (Boniva)
- Alendronate (Fosamax)
What do bisphosphonates do?
- Suppress activity of osteoclasts and inhibit bone resorption
- Interferes with maxilla and mandible boney repair after surgery leading to bone necrosis
What drug if used chronically can cause osteoporosis?
-Glucocorticoids
What do glucocorticoids do?
- Antagonize vit. D- stimulated intestinal Ca++ tranport and stimulates renal secretion
- Blocks osteoblastic function
What is Hypoparathyroidism cause by?
-It is rare and most often caused from accidental removal at thyroid surgery
What are the symptoms of Hypoparathyroidism?
- Hypocalcemia
- Decreased PTH
- Tetany
- Dental changes in children
What is Calcitonin?
- Action opposite of PTH
- Inhibits osteoclastic activity
- Used for paget’s disease
