Problem 12: Secondary Prevention of Fracture Flashcards
Explain the rationale for alendronate
Bisphosphonates are widely used to treat and prevent bone related conditions such as prevention and treatment of osteoporosis in postmenopausal women
Osteoporosis is a condition in which bones lose their strength and are more likely to break, usually following a minor bump or fall. The bones most commonly broken as a result of osteoporosis are the wrist, hip and spine. Osteoporosis can sometimes have other affects on those with the condition, such as a change in body shape and long-term pain.
Alendronic acid is first line for patients at risk of osteoporotic fragility fractures
MOA: reduce bone turnover by inhibition of osteoclasts, the cells responsible for bone resportion. Bisphosphonates are similar in structure to pyrophosphate and so are readily taken up into bone. Net effect is reduction in bone loss and improvement in mass
Explain how you would counsel Anna to take the alendronic acid
Tablets should be swallowed whole with at least 200ml of water on an empty stomacjh immediately after getting up in the morning. Patient should stay fully upright for atleast 30 minutes or one hour after taking the tablet before taking any food drink or other medicine. Stop taking and seek advice if development of any oesophageal irritation occurs.
2 clinical trials have found that an increase incidence of AF - keep under close review but no need to list as a side effect as not sufficient evidence.
Can have adverse effect on renal function
Side effects: hypophosphotaemia, oesophagitis, osteonecrosis of the jaw. Good dental care important to minimise risk of this. Atypical femoral fracture (patients on long term at risk).
When is the best time of day to take calcium supplements? Should they be taken at the same time as the alendronate?
Bisphosphonates bind calcium. Their absorption is therefore reduced if taken with calcium salts (including milk) as well as antacids and iron salts.
30 minutes should be left before taking any other medicinal product such as antacids or calcium.
Describe the alternative bone protection medicines that could be prescribed for this patient
Disodium pamidronate, zoledronic acid both bisphosphonates too
The oral bisphosphonate drugs alendronic acid, ibandronic acid and risedronate sodium are available on the NHS as possible treatments for people who have an increased risk of fracture because of osteoporosis.
The intravenous bisphosphonates ibandronic acid and zoledronic acid are available for people who have an even greater increased risk of fracture because of osteoporosis. They are also available for people who have an increased fracture risk and have problems taking oral bisphosphonates.
Etidronate and strontium renelate are both no longer marketed in the UK.
What are the safety issues with bisphosphonates?
Oesophageal reactions (oesaphagitis, ulcers and erosions)
Osteonecrosis of the jaw (normally high doses via IV)
Hypophosphotaemia
