Osteoporosis Flashcards
What is osteoporosis?
low bone mass and structural deterioration of bone tissue.
What does osteoporosis lead to?
Bone fragility and fractures in the spine, wrist, and hip
What are the functions of the skeleton?
Structural support, protect organs, contain calcium and phosphorus stores
What are the types of bone?
- trabecular/cancellous - metabolic; supplies minerals when deficient
- cortical - structural; outer bone 80% of skeleton
What are the purposes of bone remodeling?
- Repair microfractures
- adapt to weight bearing
- provide access to mineral stores
What performs bone remodeling?
- osteoclasts - bone resorption
2. osteoblasts - bone formation
What is an important part of bone remodeling?
RANKL - receptor activated of nuclear factor kappa b ligand
When is peak bone mineral density reached?
age 25-30 years
What is bone quality equal to?
bone quality = bone mass and strength
What regulated calcium homeostasis?
Regulated by vitamin D and parathyroid hormone
Explain the relationship among vitamin D, PTH, and calcium.
PTH converts vitamin D to calcitriol when calcium levels are low. PTH and calcitriol work to release calcium from bone.
What are the types of osteoporosis?
- postmenopausal - decline estrogen production
- age-related - hormone, vitamin D, calcium deficiency
- secondary cause.
How much bone loss can occur following menopause?
10-25% bone loss in 10 years following menopause
What are the clincial signs of osteoporosis?
Short stature, kyphosis, lordosis, fracture
pain, immobility
What are the complications of fractures?
Pain, deep, dull, aching.
Decrease functioning
psychological issues
What are some factors that can contribute to osteoporosis?
- female, family history, >50, menopause, low calcium, vitamin d intake, 3 drinks/day of alcohol, smoking, lack of exercise, high salt, high caffeine intake.
What diseases are factors for osteoporosis?
RA, prior fracture, hypogonadism, IBS, hyperPTH, epilepsy, diabetes, depression
What medications are factors for osteoporosis?
glucocorticoids, cyclosporine, chemotherapy, anticonvulsants, depo-medroxyprogesterone,
Who should be tested for osteoporosis?
- Women >65 Men >70
- 50-69 with risk factors
- adults w/fracture >50
- Disease or medication that can cause secondary
What does a central DXA measure?
Measures hip, spine, total body
Non-invasive, emits low radiation, lasts 10 mins
What does a peripheral DXA measure?
Measures finger, forearm, heel
Screening only
What unit is bone mineral density measured in?
g/cm2
Amount of mineralized tissue in the area scanned
What are T-scores comparing? what are the values?
Postmenopausal women and men >50 compared to younger adult of same sex.
Normal > -1
osteopenia >-2.5 <-2.5
What are Z-scores comparing? what are the values?
Premenopausal women, men -2
Below <-2
What labs are useful to identify secondary causes of bone loss?
25(OH) D - normal >30ng
CBC, CHEM, ESR, PTH, Ca, Scr, thyroid, testosterone
Bone turnover markers
What is the goal of therapy for age birth - 30?
obtain highest bone mass possible and optimize bone quality
What is the goal of therapy for age >30?
Maintain BMD, minimize bone loss, prevent falls/fractures
What is the goal of therapy for those with fractures?
Control pain, restore independence and quality of life, prevent further fractures
What is the recommended amount of daily calcium and vitamin D for adults >50?
Calcium 1200mg
Vitamin D 800-1000IU
What is the difference between Vitamin D2 and D3?
D2- ergocalciferol more potent, used in fortified foods
D3 - cholecalciferol found in OTC
Who should be treated?
Postmenopausal women or men >50
- hip, spine fracture
- prior fracture and low bone mass
- T-score 3% hip fracture
- low bone mass and 10yr >20% any fracture
What does the FRAX algorithm tell?
Estimates likelihood of a person to break a bone due to low bone mass or osteoporosis over a 10 year period.
*does not include spinal, cannot use on patients already on medications
What is the difference between calcium carbonate and citrate?
Calcium carbonate 1000mg = 400mg elemental Take with food to enhance absorption Calcium citrate 1000mg = 210 elemental Take with or without food
What drugs interact with calcium carbonate/citrate?
Iron, quinolone antibiotics, tetracyclines, levothyroxine
What is the preferred vitamin D supplement?
Cholecalciferol D3
1mg=40,000units
What are bisphosphonates mechanism of action?
Decrease osteoclast activity
increase/maintain BMD
reduce fracture risk
Which bisphosphonate does not help with hip fractures?
Boniva - ibandronate
What are the rules for administration?
Take in morning, 30 minutes prior to food, with 8 ounces of plain water, sit or stand for 30 minutes.
*exception: Boniva - ibandronate
What is the dosing for Fosamax?
Aldendronate 10mg daily po, 70mg week po
What else is Fosamax approved to treat?
Paget’s disease
Accelerated osteoclast activity
Elevated alkaline phosphatase
What is the dosing for Actonel?
Risedronate 5mg daily po, 35mg week po, 150mg month po
What is special about actonel?
Risedronate - do not need to wait 30 minutes to eat
What is the dosing for Boniva?
Ibandronate 150mg month po, 2.5mg daily po
3mg IV push q 3 months
If a patient is on daily dosing and misses a dose, when should they take the next?
Take the next morning.
If a patient is on weekly dosing and misses a dose, when should they take the next?
Take the next morning, unless >1 day then skip for that week.
What is the dosing for zoledronic acid?
Reclast 5mg IV once a year
What needs to be checked before each dose of Reclast?
Zoledronic acid
Creatinine
What are the advantages of IV formulations?
Less GI adverse effects
Improved bioavailability, increased adherence,
For patients that can’t sit/stand for 30-60minutes
What is the mechanism of action of Evista?
Raloxifene
estrogen agonist on bone
estrogen antagonist on breast/uterus
What is the dosing for Raloxifene?
60mg po daily
What is the dosing for Miacalcin?
Calcitonin 200mcg intranasally, 50mcg SC/IM daily
What is estrogens affect on bone?
Decrease osteoclast activity, inhibit PTH, increase calcium absorption, decrease calcium excretion
What drug binds to RANKL?
Denosumab (prolia)
What is Prolia mechanism of action?
inhibits osteoclastogenesis and increases osteoclast apoptosis
How is denosumab dosed?
Prolia 60mg subq once every 6 months
Which drug can cause eczema and cellulitis?
Denosumab (prolia)
Which product is a recombinant parathyroid hormone?
Teriparatide (forteo)
What is the mechanism of action of Teriparatide?
Forteo
Increase bone formation, osteroblast activity
What is considered high risk patient?
- previous osteoporotic fracture
- multiple risk factors
- low BMD <-3
- failed or intolerant to other therapies
How is Forteo dosed?
20mcg SC daily
What are the contraindications to using teriparatide?
Hypercalcemia, paget’s disease, history of bon cancer
Which drugs are available IV?
Ibandronate - Boniva 3mg IV push q3mths
Zoledronic acid - Reclast 5mg IV year
Which drugs are available SC?
Denosumab - Prolia 60mg q 6months
Teriparatide - Forteo 20mg daily
When does the greatest bone loss occur when taking glucocorticoids?
first 6-12 months of therapy
When should DXA be repeated?
Osteoporosis - 2 years
Osteopenia - 5 years
Normal/mild - 15 years
