Bisphosphonates Flashcards
Give the 4 main common clinical indications for the use of Bisphosphonates.
1) Osteoporotic fragility fractures.
2) Severe hypercalcaemia of malignancy
3) Patients with myeloma or breast cancer with bone metastases
4) First-line treatment of metabolically active Paget’s disease.
1) Which bisphosphonate is used for osteoporosis?
2) Which bisphosphonates are used for hypercalcaemia of malignancy?
1) Alendronic acid.
2) Pamidronate and Zoledronic acid.
1) Why are bisphosphonates used for patients at risk of bone metastases or with bone metastases?
2) Why are bisphosphonates used in Paget’s disease?
3) Which bisphosphonates are used for patients with myeloma and breast cancer with bone metastases?
1) To reduce the risk of pathological fractures, cord compression and the need for radiotherapy or surgery.
2) With the aim of reducing bone turnover and pain.
3) Pamidronate and Zoledronic acid.
How do bisphosphonates reduced bone turnover?
By inhibiting the action of osteoclasts which are the cells responsible for bone resorption.
1) Why can bisphosphonates be readily incorporated into bone?
2) What do bisphosphonates do in osteoclasts?
3) What is the net effect of bisphosphonates?
1) Because they have a similar structure to the naturally occurring pyrophosphate.
2) They accumulate in osteoclasts as bone is resorbed, inhibit activity and promote apoptosis.
3) Reduction in bone loss and improvement in bone mass.
1) Name 2 common side effects of bisphosphonates.
2) What is a rare but serious side effect of bisphosphonates and when is it more likely?
3) What is important to minimise the risk of this serious side effect?
4) What is an important adverse effect which can occur particularly in patients on long term treatment?
1) Oesophagitis (when taken orally) and hypophosphataemia.
2) Osteonecrosis which is more likely with high dose IV therapy.
3) Good dental care is important in order to minimise the risk of osteonecrosis.
4) Atypical femoral fracture.
1) Why should bisphosphonates be avoided in patients with severe renal impairment?
2) When are bisphosphonates contraindicated?
3) Due to the risk of osteonecrosis, when does caution need to be exercised in prescribing bisphosphonates?
1) Because they are really excreted.
2) In the context of hypocalcaemia. Oral administration is contraindicated in patients with active upper GI disorders.
3) In smokers and patients with major dental disease.
1) Why is bisphosphonate absorption reduced if it is taken with calcium salts?
2) What else can reduce bisphosphonate absorption?
1) Because bisphosphonates bind to calcium.
2) Antacids and iron salts.
1) How is alendronic acid prescribed for osteoporosis?
2) How are bisphosphonates administered for hypercalcaemia and bone metastases?
1) 70mg once weekly PO.
2) Pamidronate and Zoledronic acid are prescribed as slow IV infusions.
How are Bisphosphonates administered for patients with Paget’s disease?
Risedronate is given orally and Pamidronate as an IV infusion.
1) How can a patient taking oral bisphosphonates reduce the risk of oesophageal irritation?
2) When can you assume a diagnosis of Osteoporosis?
1) By remaining upright for 30 minutes after taking it.
2) In women aged >75 who have had a fragility fracture. Here you can start treatment with a bisphosphonate without the need for further investigation for osteoporosis.
