Term
| PTH stimulates both osteoclasts and osteoblasts, but net effect over time is bone ______. However, In lower doses, PTH can stimulate bone _____, so lower doses used to .... |
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Definition
resorption
formation
...treat osteoporosis |
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Term
| PTH: Net effect over time ____ Ca and ___ P in serum |
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Definition
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Term
| Vit D: Net effect over time ___ Ca and ___ P in serum |
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Definition
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Term
| 1,25 Vit D directly inhibits ___ |
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Definition
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Term
High levels of Ca and P:
Reduce amount of ___ produced by kidney
Reduces ___ secretion |
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Definition
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Term
| calcitonin lowers blood Ca2+ and P levels in two ways: |
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Definition
Inhibits Ca2+ absorption by the intestines
Inhibits osteoclast activity in bones |
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Term
| Calcitonin Indications: (3) |
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Definition
Paget’s , hypercalcemia, and osteoporosis (all of which have decreased Ca)
- not really sure what to think of this b/c calcitonin lowers serum Ca, but it does so in part by decreasing osteoclast activity - so good for osteoporosis |
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Term
| Glucocorticoids prolonged administration can cause: (2) |
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Definition
Osteoporosis in adults
Stunted growth in kids |
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Term
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Definition
| decreases bone resorption action of PTH and increases Vit D in blood |
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Term
| which hormone is used for osteoporosis that doesn't have a cancer risk? |
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Definition
| Selective Estrogen Reuptake Modulators (SERM’s) |
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Term
| Selective Estrogen Reuptake Modulators (SERM’s) impt side effect: |
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Definition
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Term
| Calcimimetics (Cinacalcet) |
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Definition
Activates calcium sensing receptor
1° in parathyroid gland
Blocks PTH secretion
Indications: 2° hyperPTH in kidney dz and parathyroid cancer |
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Term
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Definition
Cytotoxic antibiotic; unclear MOA
Indications: Paget’s and hypercalcemia |
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Term
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Definition
Reduces renal Ca excretion
May increase effectiveness of PTH stimulating reabsorption of Ca by kidney and increasing Na excretion
Also, reduces hypercalcemia and stone formation |
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Term
| What is not used to treat osteoporosis due to its toxicity at high levels? |
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Definition
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Term
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Definition
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Term
| Bisphosphonates end in ________ |
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| Zolentronate (Reclast, Zometa) |
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Definition
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Term
| which biphosphonate has the least GI side effects? |
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Definition
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Term
| which biphosphonate is not oral? |
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Definition
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Term
| which biphosphonate is for paget's only? |
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Definition
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Term
| Bisphosphonates: Greatest effect on _______ |
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Definition
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Term
| _________ Usually Rx’d to take with full glass of water on empty stomach and remain upright for 30minutes - so a lot of GI upset |
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Definition
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Term
| Vitamin D Deficiency: (2) |
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Definition
| rickets (children) and osteomalacia (adults) |
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Term
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Definition
| hypophosphatemia, hyperparathyroidism due to decreased vitamin D, hypocalcemia, psoriasis, osteomalacia, and renal osteodystrophy |
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Term
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Definition
| hypercalcemia and excess bone loss |
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Term
| Drugs not FDA approved for osteoporosis: (4) |
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Definition
Calcitriol (Rocaltrol, Calcijex)
fluoride
HRT
Estrogen |
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Term
| Drugs FDA approved for Tx of osteoporosis: (4) |
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Definition
Bisphosphonates
SERMs
Teriparatide (Forteo)
Calcitonin (Calcimar, Miacalcin) |
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Term
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Definition
Uncontrolled osteoclastic bone resorption
Bone formation is increased in response but often poorly organized
Elevated serum alkaline phosphatase and urinary hydroxyproline are diagnostic
DOC: calcitonin and bisphosphoates (etidronate, alendronate, risedronate, and tiludronate)
Bisphosphonates are used for 6 months and can be repeated 6 months
Goal: reduce bone pain, prevent deformity, hearing loss, cardiac failure, hypercalcemia
Etidronate toxicity results in osteomalacia and bone pain
Plicamycin can be used in short courses if calcitonin and bisphosphonates have failed |
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Term
| Vitamin D dependent Rickets |
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Definition
Autosomal recessive disease (super rare)
Same sx as rickets; but no response to low dose vitamin D supplementation
Type I – mutation in enzyme producion 1,25-dihydroxy-vitamin D
Treat with Vitamin D 4000 IU daily or calcitriol 0.25-0.4 daily
Type II – mutation in the gene for the vitamin D receptor
Treat with high doses of calcitriol |
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Term
| Ideopathic hypercalciuria |
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Definition
SSx – hypercalciuria and nephrolithiasis
Normal serum Ca and PTH levels
3 subgroups having to do with Ca absorbtion, Ca secretion, and phosphate leakage
HCTZ 50-100 mg daily
D not use loop diuretics (increase urine Ca secretion)
Allopurinol is an alternative |
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Term
| Intestinal osteodystrophy |
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Definition
Malabsorption of vitamin D due to GI and hepatic diseases
Bile contains vitamin D which should be reabsorbed in the jejunum and ileum
Mild malabsorption
Vitamin D 25000-50000 IU 3x/week
Severe disease rarely responds to vit D
Calcitrol may be helpful along with Ca and P monitoring |
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Term
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Definition
Lose vit D in urine by losing vit D-binding protein
No treatment approved or in clinical trials at this time. |
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Term
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Definition
Associated with short bowel syndromes with fat malabsorption
Many renal stones of calcium and oxalate
Treat with calcium supplementation which binds oxalate and prevent its absorption |
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Term
| Vitamin D deficiency/insufficiency |
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Definition
Deficiency: 25-vit D levels <10ng/mL
Insufficiency: 25-vit D levels 10-32 ng/mL
Common in pediatric, geriatric, and vegetarian patients and those with reduced sun exposure
800-1200 IU of vitamin D |
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Term
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Definition
Causes loss of 1,25-vit D production due to impact on bone mineral homeostasis:
Decreases Ca absorption from intestine
Retains P levels
Hyperparathyroidism results
Osteomalacia and osteitis fibrosa results
Doxercalciferol (Hectoral) and paricalcitol (Zemplar) are approved for treatment of 2° hyperhparathyroidism due to chronic kidney disease |
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Term
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Definition
Sx associated with Hypercalcemia
Surgery is best
Cinacalcet (calcimimetic) in clinical trial for 2° hyperparathyroidism (future treatment?) |
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Term
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Definition
Usually caused by absence of PTH causing hypocalcemia and hyperphosphatemia and low vitamin D levels
Vitamin D 25000-100000 IU 3x per week with Ca supplementation
Calcitriol is also an option |
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Term
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Definition
Causes: Renal failure, hypoparathyroidism, vitamin D intoxication
Treatment: dialysis, glucose and insulin infusions, dietary restriction
Rarely an emergency |
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Term
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Definition
Causes: Hyperparathyroidism, vit D deficiency, hypercalciuria, rickets
Longterm Sx: proximal muscle weakness, osteomalacia
Rarely an emergency
In X-linked and autosomal dominant disease, treatment with oral phosphate and calcitriol has offered encouraging results. |
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Term
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Definition
Sx: neuromuscular – tetany, paresthsias, laryngospasm, muscle cramps, convulsions
Causes: hypoparathyroidism, vit D deficiency, kidney dz, malabsorbtion
Treatment:
Calcium – IV, IM, PO forms
Calcium gluconate is least irritating to veins
Calcium carbonate is PO choice because of ready availability
Vitamin D
1,25 vit D is form of choice raising Ca in 24-48 hours |
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Term
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Definition
Sx: CNS depression including coma
Causes: hyperparathyroidism, cancer, sarcoidosis, hypervitaminosis D, etc.
Requires emergency lowering of serum calcium:
Saline diuresis with furosemide
Bisphosphonates (pamidronate, zoledronate)
Calcitonin – (ancillary) lacks toxicity
Gallium nitrate – inhibits bone resorption (toxic)
Plicamycin – toxic causing thrombocytopenia
Phosphate – fastest way to reduce Ca, used after other methods fail
Glucocorticoids – reponse over days |
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