| A | B |
|---|
| Ergocalciferol | Vitamin D2 |
| Cholecalciferol | Vitamin D3 |
| calcifediol | Product of 25-hydroxylation in liver |
| calcitriol | Product of 1-hydroxylation in kidney |
| DHT—dihydrotachysterol | Vitamin D analog no 1-OH needed for activation, does need liver 25-OH |
| 1a-Hydroxycholecalciferol | Vitamin D analog already has 1-OH group |
| Doxercalciferol (1-hydroxyvitamin D2) | Vitamin D analog, does need liver 25-OH |
| 22-oxacalcitriol MOA | suppressor of PTH gene expression, limited action on intestine and bone |
| 22-oxacalcitriol therapeutics | used in chronic renal failure, primary hyperparathyroidism |
| 22-oxacalcitriol indications | low affinity for serum binding protein leads to longer half-life than calcitriol |
| Estrogens | act on osteoblasts to decrease osteoclast recruitment and activation |
| Calcitonin | direct effect on osteoclast to decrease bone resorption |
| Calcitonin | decrease calcium and phosphate reabsorption in kidney |
| Glucocortiocoids | antagonize Vitamin D stimulated intestinal calcium absorption |
| stimulate renal calcium excretion | Glucocortiocoids |
| increase PTH stimulated bone resorption | Glucocortiocoids |
| block bone collagen synthesis | Glucocortiocoids |
| bisphosphonates indications | Non-hormonal Tx for osteoperosis |
| bisphosphonates MOA | retard formation and dissolution of hydroxyapatite imbibed by osteoclasts |
| close to pyrophosphate | bisphosphonates structure |
| bisphosphonate metabolism | metabolized into ATP analog, accumulates in osteoclasts |
| etidronate and tiludronate side effects | impairs cell function and viability, induces apoptosis |
| alendronate MOA | inhibition of protein prenylation important for osteoclast function |
| alendronate | less side effect of decrease bone mineralization |
| gastric irritation common with all bisphosphonates except | etidronate |
| zoledronate toxicity | some renal toxicity |
| Estrogens decrease | IL-6, IL-1, TNF-? |
| Estrogens increase | IGF-1, BMP-6, TGF-? |
| plicamycin | cytotoxic antibiotic that also decreases plasma [Ca++] by inhibiting bone resorption |
| gallium nitrate | inhibits bone resorption, renal toxicity |
| oral sodium phosphate | binds free ionized calcium, high risk procedure |
| edetate disodium (EDTA) | calcium chelator, high risk procedure |
| cinacalcet MOA | inhibits PTH secretion by lowering the[ Ca++] at which PTH secretion is suppressed |
| cinacalcet | calcimimetic |
| cinacalcet indications | 1' and 2' hyperparathyroidism and hypercalcemia of parathyroid carcinoma |
| thiazide diuretics | inhibit renal calcium stone formation by reducing renal calcium excretion |
| fluoride | both acute and chronic toxicities limit use |
| fluoride MOA | accumulates in bone and teeth may stabilize hydroxyapatite |
| Hypercalcemia tx | Bisphosphonates, calcitonin, plicamycin, gallium nitrate, phosphates, glucocorticoids |
| Osteoporosis tx | Bisphosphonates, calcitonin, vit D analogs, Ca+ supplements, thiazides, intermittent teriparatide |
| Paget’s disease tx | Calcitonin, bisphosphonates |
| Hypoparathyroidism tx | Vitamin D analogs |
| Hyperparathyroidism tx | oxacalcitriol, cinacalcet |
| renal osteodystrophy tx | Vitamin D analogs, phosphate binders |
