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33 Cards in this Set
- Front
- Back
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How does pH affect solubility of Ca?
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Increased solubility in an acid environment (low pH)
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What are adverse reactions to Calcium ingestion?
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- hypophosphatemia
- hypercalcemia - CONSTIPATION - nausea/vomiting/anorexia - Milk-Alkali Syndrome (with high, chronic dosing or renal failure |
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What are contraindications to Calcium ingestion?
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- Hypercalcemia
- Hypophosphatemia - Renal Calculi - Digitoxin Toxicity (if suspected) |
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What are drug/food interactions with Calcium?
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- Levothyrine - Calcium Carbonate (and other Ca salts) decreases T4 absorption -- MUST separate dose by 4 hours!!
- Calcium Channel Blockers - effects may be diminished - Thiazide Diuretics - cause hypercalcemia - Digitoxin - may potentiate toxicity - Food - increases Ca absorption (increased acidity); EXC bran, foods high in oxalates, whole grain- decrease Ca absoroption - Proton Pump Inhibitors or H2 blockers - less absorption of Calcium Carbonate |
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What two CalciumSalts give you the highest amount of elemental Ca when absorbed?
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- Calcium Carbonate = most! (better absorbed with meals)
- Calcium Citrate = second (better absorbed when fasting) |
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What is important to know about IV Ca preparations?
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Must diluee with D5W or saline
- Concentrated calcium can irritate veins and extravasate outside to cause tissue necrosis |
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What are the indications for taking Calcium?
What are the indications for IV Ca? |
Uses:
- antacid - tx/prevent Ca deficiency (osteoporosis, osteomalacia, renal insufficiency, rickets, hypoparathyroidism, etc.) - tx/prevent hyperphosphatemia IV Ca: for symptomatic hypocalcemia!!! = 7 mg/dL ...... parasthesias, tetany, hypotension, seizures, Chvostek's Sign, Trousseau's Sign, bradycardia, prolonged QT interval |
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What else should be given with Calcium for better/healthier effects?
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Magnesium!!
Mg depletion causes hypocalcemia - causes PTH resistance (mild Mg-dependence) - causes decrease in PTH secretion (severe PTH dependence) |
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What is the MAJOR source of vitamin D?
Minor source? |
Major Source: dermal synthesis (or fortified foods)
Minor Source: few foods - fatty fish, eggs |
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Vitamin D
- MOA? - functions? |
- binds to nuclear receptor and enters nucleus --> binds to DNA-binding region of chromosome --> increased production of mRNA for Ca-binding proteins
--> increases intestinal Ca AND PO4- absorption --> amplifies effects of PTH on bone --> inhibits PTH transcription in chief cells in parathyroid (neg feedback) --> minor effect on kidney - increase Ca reabsorption |
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What is a sufficient Vitamin D value?
What is the value for Vitamin D deficiency? Tx?? |
Vit D should be >30 ng/mL
< 30 ng/mL = deficient (<10 ng/mL = VERY deficient) Tx: 50,000 IU once a week for 8 weeks... then maintain 800-1000 IU/day |
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Calcitrol
- what is? - why good? - function? |
= synthetic vitamin D analog
- already active, so doesn't have to be metabolized to be active - regulates absorption on Ca from GI tract and its utilization in body - stimulates Ca transport |
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What are the indications for Calcitrol?
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- hypocalcemia
- hypocalcemia in postsurgical hypoparathyroidism - idiopathic hypoparathyroidism - pseudohypoparathyroidism |
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What are the adverse effects of Calcitriol?
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- excessive dosing --> intoxication (hypercalcemia/uria, confusion, vomiting, muscle weakness, bone pain, etc.)
- in kids: brain damage - can have digoxin toxicity |
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What is the safe upper limit do Vitamin D?
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2000 IU/daily
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What is the warning with diuretic therapy pertaining to calcium balance?
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- Loop Diuretics: increase Ca excretion
- Thiazide Diuretics: Decrease Ca excretion - hypocalcuric effect --> protect against Ca stones and possible bone loss |
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What are the universal recommendations for all patients' Calcium and Vitamin D intake??
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- Ca: 1200 mg/day elemental Ca for women over 50
- Vitamin D - 800 IU/day for ppl at risk of deficiency - elderly, chronically ill, housebound, institutionalized ppl |
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Bisphosphates
- what are? - MOA? - Pharmacokinetics? - Uses? |
= anti-resorptive agents
MOA: - inhibit osteoclast bone resorption by stopping them from adhering to boney surfaces, forming ruffled borders, and producing necessary proteins - decrease osteoclast cell number (apoptosis) - unknown how Pharm: - poorly absorbed from GI tract (1-5% oral dose); best on empty stomach - only 20% absorbed taken up by bone- rest cleared by kidney - long half-life Uses: - hypercalcemia - osteoporosis - Paget's disease |
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Bisphophonates
- Adverse Effects? - Contraindications? - Drug Interactions? |
Adverse Effects
- Osteonecrosis of jaw - often after dental extraction, infection, trauma - often with IV bisphosonates - avoid dental work!!! - GI - abdom pin, nausea, acid reflux - Hypocalcemia - Eyes - pain, blurred vision (rare) - Musculoskeletal pain (rare) Contraindications - hypocalcemia - abnorms of esophagus which delay emptying Drug Interactions - TAKE ON EMPTY STOMACH! These will decrease absorption: - Antacids - Ca salts - Mg salts - Fe salts |
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What Bisphosphonates are recommended for prevention/tx of Osteoporosis?
- what pop? |
Alendronate and Risedronate
- postmenopausal women - males - prevention of osteopoosis secondary to glucocorticoids - Paget's Disease |
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What are the IV Bisphosphonates?
Indications? |
Pamidronate
- hypercalcemia of malignancy - multiple myeloma and breast cancer causing osteolytic lesions - Paget's Disease ... Associated with development of Nephrotic Syndrome Zoledronic Acid - hypercalcemia of malignancy - multiple myeloma - metastatic bone lesions from solid tumors ***Once/year infusion for tx of osteoporosis!! - Associated with renal impairment (monitor creatinine) |
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How do Bisphosphonates work in Paget's Disease?
- which ones are indicated? |
They do inhibit resorption (indirect decrease in bone formation), but the newly formed bone has more normal architecture.
* MUCH higher doses than for osteoporosis..... - alendronate - risedronate - pamidronate |
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Calcitonin
- where formed? - function? |
- Produced by Parafollicular C-Cells that surround thyroid follicular cells --> released in response to INCREASED plasma ionic Ca
- inhibits Osteoclasts and stimulates Osteoblasts [primary function] - decreases plasma Ca - increases Ca and PO4- excretion - decreases calcitriol synth by kidney --> inhibits absorption of Ca and PO4- by kidney |
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What are the indications of Calcitonin?
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(WEAK)
- Paget's Disease - Osteoporosis (reduces vertebra fractures, analgesic effect) |
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Estrogen/Hormonal Therapy
- approved indications by FDA? |
Indications: (menopause)
- prevent osteoporosis - relieve vasomotor sx - relieve atrophic vulvovaginitis |
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What is the big problem with estrogen therapy??
What does the FDA suggest? |
Increased risk of MI, stroke, invasive breast cancer, PE, DVT for 5 years...
Sooo... if being used solely for prevention of osteoporosis - consider non ET!!! |
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When should Estrogen Therapy be supplemented to Hormone Therapy?
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When no hysterectomy - HT contains Progestin to protect uterine lining
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Raloxifene
- what is? - use? - problems?? |
= Selective Estrogen Receptor Modulator (SERM)
- prevent/tx osteoporosis in postmenopausal women - problem: increases risk of DVT and increases hot flashes |
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Teraparatide
- what is? - how is it this?? - function? - paradox? |
= Recombinant Human PTH
(N-terminal portion is identical to PTH's - this is the actie area) Functions (similar to PTH): - stimulate osteoblasts - increase GI Ca absorption - increase renal tubular Ca reabsorption Paradox: chronic exposure to high serum PTH results in one resorption; intermittent admin of RECOMBO human PTH stimulates bone FORMATION > resorption |
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Teraparatide
- annoying thing about using it? - adverse effects? - warnings/precautions?? - contraindications? |
ugh! - syringes must be refrigerated
Adverse Effects - chest pain - syncope - depression - n/v - vertigo, dizziness.... Warning: - associated with increase in osteocarcoma - do NOT use > 2 years (avoid in pts with increased risk; not for kids) ***Not a first-line tx!!! Contraindications: - patients with pre-existing malignancies, renal stones, renal insuf, gout - primary/secondary hyperparathyroidism |
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Teraparatide
- use?? - candidates for this tx? |
Use:
- tx osteoporosis in postmenopausal women at high risk of fracture - tx of primary of hypogonadal osteoporosis in men at high risk of fracture Candidates: - men/women with severe osteoporosis - pts unable to tolerate bisphosphonates and fail other osteoporosis txs ***NOT FIRST-LINE TX! |
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What is the benefit of Teraparatide PLUS bisphosphonates?
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- NONE!!!
(thought since tera stims bone formation and bisphos decrease resorption, would work great together... nope!) |
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What is recommended after a patient stops Teraparatide tx? Why?
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Use an antiresorptive agent (bisphosphonate!!)
... bc can only use for 2 years and gains of BMD decline after stop tx... |
