Osteoporosis Flashcards
General notes on bone density, and when skeletal mass is “max” and when begins to decline
- Two primary processes that maintain bone density are about equal:
1) Resorption: osteoclastic activity
2) Formation: osteoblastic activity - Skeletal mass is at its “max” at roughly the age of 35.
- Then begins to decline around the age of 40 for women (i.e., within 2 years of menopause)
When is bone loss greatest?
- The rate of relative loss increases in women within 2 years of menopause.
- Result: A third to half of all bone will be lost during the first 5 years after menopause.
Risk factors for osteoporosis:
Independent risk factors
- Age
- Previous fracture
- Long-term glucocorticoid
- Current smoking
- Hip fracture in a parent
- More than three alcohol drinks a day
- Weight under 127 pounds
DX for osteoporosis:
Diagnosis:
- Standardized test: BMD, usually at hip and spine
- Well-defined criteria: T-score
FRAX SCORE: Fracture Risk Assessment
- Age: 40–90 years
- Sex
- Weight
- Height
- Any history of previous fractures
- Parental fractured hip
- Smoking history
- Glucocorticoids
- Diagnosis of RA
- Secondary osteoporosis: Type I insulin dependent DM, osteogenesis imperfecta, untreated hypothyroidism (longstanding), hypogonadism, premature menopause (
RX options for osteoporosis:
1) Alendronate, risendronate
Decrease vertebral and nonvertebral fractures
2) Weekly ibandronate
Decreases vertebral fractures
No fracture data for monthly form
3) Raloxifene
Decreases vertebral fractures
4) Bisphosphonates, selective estrogen receptor modulators (SERMs)
Can be classified as antiresorptive agents
Main role is to block osteoclast activity
Effects are aimed to block either further decrease of bone density or deterioration of skeletal microarchitecture
Prevention of osteoporosis:
-Modify the modifiable risk factors
-Assure adequate calcium and vitamin D intake
Vitamin D 600–1000 units/day
Elemental calcium 1000–1200 mg/day total
Read labels: calcium carbonate 500 mg has 200 mg of elemental calcium
-Use calcium citrate in achlorhydria (PPIs and H2Bs)
-Use calcium carbonate with meals for everyone else
-Maximum absorbable dose at one sitting: 500 mg elemental
Preventing osteoporosis:
- Consider preventative medication if patient has low bone mass and risk factors.
- Use the Frax score to assess 10-year risk of hip and any osteoporotic fracture.
- Discuss treatment options with patients who have 10-year risk of 3% or more for hip fracture, or 25% or more for any osteoporotic fracture:
1) Alendronate 35 mg/week
2) Risendronate 35 mg/week
3) Ibandronate 150 mg/month
4) Raloxifene 60 mg daily
Osteoporosis: TX
-Modify the modifiable risk factors
-Assure adequate calcium and vitamin D intake
Especially if planning to use bisphosphonates
-Bisphosphonates
Formulations
Alendronate (Fosamax) 70 mg/week
Risedronate (Actonel) 35 mg/week
Ibandronate (Boniva) 150 mg/month
Zoledronic acid yearly infusion (for patients who fail oral therapy)
Monitoring in TX of osteoporosis:
Monitoring
- Check bone density after 2 years to ascertain response
- If BMD continues to decrease, assess compliance and other illnesses
- Consider stopping at 5 years and checking BMD after 2 years off
Biphosphonates: adverse effects
-Esophageal injury
Take as directed, avoid in dysmotility
-Jaw osteonecrosis (rare, usually cancer patients on IV)
Assure good dental care
Consider 3-month holiday for jaw procedures
-Atypical femur fracture (rare, associated with long-term use)
May have prodrome of groin or midthigh pain
Stop medication and assess with plain film or MRI
-Diffuse musculoskeletal (MSK) pain
Causality unclear
May not resolve with decrease of medications
Evista: Selective estrogen receptor modulator (SERM)
Selective estrogen receptor modulator (SERM)
=Prevents the increased risk of breast and uterine cancer associated with estrogen, while maintaining bone integrity
-Approved for the treatment of osteoporosis
* Protects against spine fractures but not hip fractures
* Does not diminish hot flashes
* Same risk of thromboembolism as estrogen
* Needs to be taken with vitamin D and often Ca preparation to promote Ca transport in the intestines
