Makindo Medical Notes

Related Subjects: |Calcium Physiology |Hypercalcaemia |Bisphosphonates |Osteoporosis |Osteonecrosis of the jaw

1. Cancer patients need a dental check before treatment, or as soon as possible after starting treatment, to avoid osteonecrosis of the jaw.
2. Atypical femoral fractures are rare but have been reported with prolonged bisphosphonate treatment for osteoporosis. Review risks and benefits after 5 or more years of use.

About: Always check the BNF link here

• Bisphosphonate

Mode of action

• Synthetic analogues of pyrophosphate such that the normal P-O-P bond has been replaced with P-C-P.
• The new analogue binds to bone and cannot be hydrolysed.
• Inhibit osteoclasts and reduce bone resorption and increase bone mineral density and so maintains the hydroxyapatite crystal structure
• Bisphosphonates may have additional functions on bone metabolism such as on the mevalonate pathway
• The primary and main indication for prescription is not measured bone mineral density but fracture risk. This includes assessing the risk of falls and the likelihood of falls in the context of Bone mineral density.

Indications

• Ensure patients are replete with calcium and vitamin D before treatment
• Osteoporosis - postmenopausal and steroid-induced, Hypercalcaemia, Paget's disease
• Reduce vertebral fractures - Etidronate, Alendronate, Risedronate and ibandronate
• Reduce hip fractures - Alendronate, Risedronate, ibandronate
• Malignant bone disease e.g. Multiple myeloma, prostate cancer, lung cancer, and other solid tumour s

Dose range: ensure patient is hydrated before each dose and assess renal function

Atypical femoral fractures have been reported rarely with bisphosphonate treatment, mainly in patients receiving long-term treatment for osteoporosis. The need to continue bisphosphonate treatment for osteoporosis should be re-evaluated periodically based on an assessment of the benefits and risks of treatment for individual patients, particularly after 5 or more years of use. Patients should be advised to report any thigh, hip, or groin pain during treatment with a bisphosphonate. Discontinuation of bisphosphonate treatment in patients suspected to have an atypical femoral fracture should be considered after an assessment of the benefits and risks of continued treatment.

Interactions

• Avoid other nephrotoxic drugs e.g. NSAIDs, thalidomide, radiographic contrast dye

Contraindications

Side effects

• Hypophosphataemia, anaemia, myalgia, arthralgia, GI disturbances, AF, headache, dizziness, renal impairment, Rarely osteonecrosis of the jaw
• Acute-phase reaction after first and second dose with pain and fever and flu-like symptoms, Nausea, vomiting, Hypocalcaemia

References

• Zoledronic acid in BNF