Corticosteroids, aromatase inhibitors and androgen deprivation therapy (in men) represent the principal causes of drug-induced osteoporosis. Assessment of fracture risk and the need for prophylaxis with bone-sparing agents amongst patients treated with these agents should be a priority for GPs.
There are European Oncology Guidelines for bone health in breast cancer and prostate cancer, as well as NICE prostate cancer guidelines that should have been assimilated into algorithms by your local oncology services to specifically manage these patients.
Residential care and nursing homes
Hip fractures are 3.3 times more common in residential-home populations than in community-dwelling older people; therefore, this is an important target group. Those who have had prior fragility fractures require bone-sparing therapy and high-dose calcium and vitamin D, as recommended by NICE and NOGG. Often previous fractures will not have been coded so a review of case records may be needed if a reliable history is not available from the patient or family.
For institutionalised elderly people without prior fragility fractures, high-dose calcium and vitamin D supplements (1200 mg/800 IU per day) used alone can reduce hip fracture risk by 43% within 18 months, and improve falls risk. Giving a choice between preparations that can be swallowed, chewed or dissolved may improve adherence.
Bisphosphonates and strontium ranelate need to be taken correctly to optimise absorption, so dosing instructions need to be discussed in detail with those responsible for drug administration in care homes and filtered down to all staff. Giving once-weekly or monthly bisphosphonates all on the same day may improve dosing accuracy. High staff turnover means frequent reminders are important.
Every practice will have patients who need bone-sparing therapy and who have lapsed. Many more will fail to continue calcium and vitamin D supplements. Reasons for lapse include:
• Not being aware of the need to continue or that long-term therapy is required
• Being intolerant of the therapy
• Difficulties remembering to take the therapy
• Difficulties complying with dosing instructions
• Accidentally discontinuing on admission/discharge
Comparing those taking each drug one year previously with a list of current users will identify recent lapsers, who can be reviewed first. Searching backwards will identify preceding cohorts of lapsers. Identifying lapsed patients can be combined with reviewing the appropriateness of the therapy and co-prescribing calcium and vitamin D.
Alerts can be added to notes/prescribing screens for opportunistic discussion in surgery or when ordering prescriptions, or patients can be written to and invited to discuss restarting therapy with an appropriate drug with a doctor or nurse.
Every practice will have patients on bone-sparing therapies who do not need them. As many as 50% of patients in receipt of bone-remodelling agents have no record of a diagnosis of osteoporosis. These may be people who were started inappropriately, those using adjuvant therapies during steroids that have been stopped or those who have been on therapy long term and no longer have osteoporosis.
To find these patients:
• Search for those taking bisphosphonates, raloxifene and strontium ranelate on acute and repeat prescriptions.
• Agree which guidance or guidelines you will follow (e.g. NICE or SIGN guidelines for postmenopausal women, NOGG for men, Royal College of Physician corticosteroid-induced osteoporosis guidelines for those on corticosteroids). If using NICE guidance, decide how rigidly you will interpret it.
• Work your way through the list of patients, identifying when and why therapy was initiated and judge if it is still appropriate. Make notes initially on your search sheets.
• While reviewing each record, check that the drugs are prescribed generically, that the patient is persisting with therapy, that adjuvant calcium and vitamin D are prescribed and whether coding is accurate. A data collection table can be downloaded.
You are likely to identify:
• Patients being treated appropriately: continue treatment.
• Lapsed patients: phone to discuss therapy; many will be intolerant and need a therapy change.
• Patients where it is not clear why therapy was started or continues: discuss these in a clinical meeting as colleagues may be able to clarify; many may be able to discontinue treatment.
Keep notes of patients in each category. Repeat the process after 6 months.
Patients without co-prescriptions
About half of patients on bisphosphonates may not have been prescribed calcium and D3. Start with your list of patients on bone-sparing therapies. Assess dietary calcium intake and whether the patient is taking over-the-counter preparations. In light of your findings, check whether each patient has been appropriately co-prescribed a calcium (1000-1200 mg/day) and vitamin D (800 IU/day) preparation. See the list of treatments within the Initiation section. Ensure that all are prescribed generically but that generic 'calcium and vitamin D tablets BPC' are not used as these contain very little calcium. Review compliance/adherence with therapy.
You may want to check that those not receiving adjuvant therapy do not have hypercalcaemia or other contraindications. These supplements are not contraindicated in stone-formers.
Review interactions, contra indications and precautions according to Summary of Product Characteristics and British National Formulary. Patients taking strontium ranelate need to ensure their second dose of calcium and vitamin D is taken at least 2 hours before their strontium ranelate; it may be easier to use a once-daily preparation taken in the morning. Strontium ranelate should be suspended during treatment with oral tetracycline or quinolone antibiotics, or if the patient develops cardiovascular risk factors. Patients taking strontium ranelate need to be re-assessed every 6 months. Thyroxine affects the absorption of both strontium and calcium and should be given separately.