Disorders of bone metabolism Flashcards
Osteoporosis is
a progressive bone disease characterised by low bone mass and is measured by Bone Mineral Density (BMD). As a result, this leads to an increased risk of fragility fractures.
Osteoporosis occurs most commonly in
postmenopausal women, men over 50 and in patients taking long-term oral corticosteroids (glucocorticoids).
Osteoporosis risk factors
age, low BMI, cigarette smoking, excess alcohol intake, lack of physical activity, vitamin D deficiency, low calcium intake, family history of hip fractures and early menopause
Overcoming the risk factors
is the lifestyle advice (stop smoking, reduce alcohol intake etc.) Patients should ensure an adequate intake of calcium and vitamin D through dietary changes - elderly patients who are housebound can benefit from supplements
Glucocorticoid therapy is associated
with bone loss and an increased risk of bone fractures. The greatest rate of bone loss occurs early after initiation and increases with dose and duration of therapy.
Bone protection treatment should be considered for
those taking long-term glucocorticoid therapy, high doses (prednisolone >7.5mg daily), for women aged over 70 or with previous fragility fractures.
Men having long-term
androgen deprivation therapy for prostate cancer have an increased risk of fractures. Oral bisphosphonates - Alendronic acid or riserdronate are recommended 1st line in men
Teriparatide is reserved for
postmenopausal women with sever osteoporosis at very high risk of vertebral fractures. Its duration of treatment is limited to 24 months
The therapeutic options for drug prevention and treatment of osteoporosis in postmenopausal women, men and those taking glucocorticoids are the same:
- Oral Bisphosphonates: Alendronic acid and risedronate sodium are the 1st line choices due to their broad spectrum of anti-fracture efficacy.
- Both drugs have been shown to reduce the occurrence of vertebral, non-vertebral and hip fractures.
- HRT is an additional option and is generally restricted for younger postmenopausal women with menopausal symptoms who are at a high risk of fractures. This is due to the risk of adverse effects e.g. cardiovascular disease and cancer in older postmenopausal women and women on long-term HRT.
- IV bisphosphonates are an alternative option for those who are intolerant of oral bisphosphonates or in whom they are con
Bisphosphonates: further information
• MHRA: The risk of osteonecrosis of the jaw is greater in patients receiving Bisphosphonate I.V. treatment for cancer) Patients should maintain good oral hygiene and have regular dental check-ups.
o Risk factors: potency of bisphosphonate (highest for zolendronate), route of administration, cumulative dose, duration and type of malignant disease, concomitant treatment, smoking, comorbid conditions and a history of dental disease
• MHRA: Benign idiopathic osteonecrosis of the external auditory canal has been reported very rarely with bisphosphonate treatment, mainly in patients receiving long-term therapy (>2 years)
o Risk factors: steroid use, chemotherapy, infection, ear operation or cotton-bud use
o Advise patients to report any ear pain, discharge from ear or an ear infection during treatment
• MHRA: Atypical femoral fractures (thigh bone fractures) have been reported rarely, mainly in patients receiving long-term treatment. Patients should report any thigh, hip or groin pain during treatment.
• Alendronic acid should be avoided in pregnancy + breastfeeding
• Severe oesophageal reactions have been reported with Alendronic acid. Patients should stop treatment and seek medical attention if they develop oesophageal irritation, dysphagia or worsening heartburn, pain on swallowing or retrosternal pain.
How is alendronic acid taken
• It is taken once daily (10mg) or alternatively once weekly in women (70mg), and once daily (10mg) in men with a full glass of water whilst sitting or standing. It should be taken at least 30 minutes before breakfast and other medicines and the patient should remain upright for a further 30 minutes after administration.
• Bisphosphonates are recommended for treating osteoporosis in patients, only if:
o The person is eligible for risk assessment as defined in the full NICE guideline on osteoporosis and
o The 10-year probability of osteoporotic fragility fracture is at least 1%
Bisphosphonate treatment should be reviewed after
• 5 years of treatment with alendronic acid, risedronate or ibandronic acid and after 3 years of treatment with zolendronic acid.
• Teriparatide is recommended as an alternative option for secondary prevention of osteoporotic fragility fractures in postmenopausal women:
o Who are unable to take alendronate and risedronate or have a contraindication to or are intolerant of alendronate and risedronate or who have had an unsatisfactory response to treatment with alendronate or risedronate, and
o Who are >65 years and have a T-score of -4 standard deviations (SD) or below, or a T-score of -3.5 SD or below, plus more than 2 fractures or who are aged 55-64 years and have a T-score of -4 SD or below plus more than two fractures.
MHRA: Denosumab
Risk of: Atypical femoral fractures, Osteonecrosis of the jaw, Hypocalcaemia, Osteonecrosis of the external auditory, Significant hypercalcemia after discontinuation of denosumab treatment for giant cell tumour of bone, Malignancies involving bone
