Drugs for Osteoporosis
A drug Information Sheet
What is osteoporosis?
Bone is a solid structure, essential for support and protection of vulnerable internal organs. However, it is a living tissue, constantly undergoing renewal from infancy to old age.
In osteoporosis, bone is not as strong as normal bone. It is lighter, more 'brittle' and more susceptible to fracturing (breaking). The diagnosis of osteoporosis is based on assessing risk factors together with bone density scanning (preferably of the hip and spine) where this is available. (See arc booklet 'Osteoporosis'.)
Why am I being treated?
The aim of treatment is to reduce the risk of fractures now and in the future. Treatment of osteoporosis involves both attention to lifestyle risk factors (for example taking more exercise) and drug therapy. Together these can prevent further deterioration and can often improve the strength of bone, reducing the risk of fractures.
The drugs currently available are listed in the following table. Individual drugs and groups of drugs are discussed below.
DRUGS USED IN THE TREATMENT OF OSTEOPOROSIS |
||
|---|---|---|
DRUG (with examples of brand names in brackets) |
HOW TAKEN |
HOW OFTEN |
| BISPHOSPHONATES | ||
| Alendronate (Fosamax) | By mouth | Daily or weekly |
| Risedronate (Actonel) | By mouth | Daily or weekly |
| Ibandronate (Bonviva) | By mouth | Monthly |
| By injection into the vein | Every 3 months | |
| Etidronate (Didronel) | By mouth | For 2 weeks every 3 months |
| Pamidronate (Aredia) | By injection into the vein | Every 3 months |
| Zoledronate (Aclasta) | By injection into the vein | Annually |
| PARATHYROID HORMONE | ||
| Teriparatide (Forsteo) | By injection under the skin (self-administered) | Daily for 18 months |
| Parathyroid hormone (Preotact) | By injection under the skin (self-administered) | Daily for 2 years |
| OTHER OSTEOPOROSIS TREATMENTS | ||
| Raloxifene (Evista) | By mouth | Daily |
| Calcitonin (Miacalcic) | By nasal inhalation | Daily – either long-term or (in treating painful vertebral fractures) for a few weeks |
| By injection under the skin or into a muscle | Daily or twice daily for a few weeks | |
| Strontium ranelate (Protelos) | By mouth (mixed with water) | Daily |
| Calcitriol (Rocaltrol) | By mouth | Twice daily |
| HORMONE REPLACEMENT THERAPY (HRT) | ||
| Most forms of HRT may be used for the treatment of post-menopausal osteoporosis. Contains oestrogen. Women who have not had their uterus (womb) removed will also need to take a progestogen. | By mouth, patches, topical gels, implants | Often daily, but less frequently with some patches and implants |
| CALCIUM AND VITAMIN D (usually used in addition to other treatments) | ||
| Calcium and vitamin D in combination: Various prescription-only and over-the-counter preparations | By mouth | Daily or twice daily |
| Calcium only: Various prescription-only and over-the-counter preparations | By mouth | Daily or twice daily |
Drugs used in the treatment of osteoporosis
Bisphosphonates
There are several different bisphosphonates and, although all work in a similar fashion, there are important differences among the individual preparations which need to be taken into consideration when making a choice. If you cannot take bisphosphonates by mouth, then intravenous treatments (treatments given by injection into a vein) are available.
- Treatment by mouth Those bisphosphonates which are taken by mouth (alendronate, risedronate, ibandronate and etidronate) are generally poorly absorbed and should be taken on an empty stomach. To reduce the risk of side-effects it may be recommended that you take the bisphosphonate with water and remain upright for up to 1 hour afterwards. You should follow the instructions given about the medication that you are taking. If you are unsure about these you should ask your doctor, rheumatology nurse specialist or pharmacist.
- Intravenous treatment Pamidronate is given by slow injection into a vein (intravenous infusion). This takes about an hour and the infusion can be repeated every 3 months. Zoledronate is also administered by intravenous infusion but only needs to be given once a year, in an infusion lasting 15 minutes or more. As well as being taken by mouth, ibandronate can be given intravenously – every 3 months from a pre-prepared syringe. This injection takes only seconds.
Bisphosphonates are generally very well-tolerated and safe drugs. Some people do have indigestion with the oral preparations but the risk is reduced if they are taken strictly according to the manufacturers' instructions. Occasionally rashes, soreness of the mouth, flu-like symptoms, bone pain and headaches have been reported. Any side-effect should be reported to your doctor or rheumatology nurse and the drug discontinued if necessary.
There are a few very rare side-effects which most doctors will never encounter. These include eye inflammation and a condition known as osteonecrosis of the jaw, where an area of bone is exposed through the gum and a small amount of bone dies. This condition is much more common in the presence of cancer, in those receiving chemotherapy, or in those with severe, recurrent dental infections and undergoing dental procedures.
It is essential to ensure there are no deficiencies of calcium and vitamin D when taking bisphosphonates, otherwise their effect is potentially lessened. Most clinicians recommend a daily prescribed supplement of calcium and vitamin D.
Teriparatide and parathyroid hormone
Naturally-occurring parathyroid hormone is produced by four small glands which lie close to the thyroid gland in the neck. This hormone is concerned with the regulation of calcium levels in the blood. Teriparatide is not the naturally-occurring hormone but is very similar. It comes in a syringe which resembles a pen, and is self-administered under the skin (subcutaneously), usually in the abdomen or thigh. It is usually given every day for an 18-month course.
Teriparatide is usually very well tolerated. Side-effects include slight irritation at the injection site and occasional troublesome bone pain. It must not be given in the presence of high calcium levels or where there is existing overactivity of parathyroid glands. It should not be used in people who have had radiotherapy to their bones, for example as part of the treatment for breast cancer. It is effective but expensive, and is currently reserved for treatment of severe osteoporosis in women and men.
Recently parathyroid hormone itself has also become available in a manufactured form. As with teriparatide, it is self-administered subcutaneously once daily, by 'pen'.
Raloxifene
Raloxifene is used for the treatment of osteoporosis in post-menopausal women. Its benefit is confined to the spine. It mimics some of the beneficial effects of oestrogen on bone but has fewer risks. For example, while it increases the density of the vertebrae (the bones of the spine) and reduces vertebral fracture rates, it also reduces the risk of breast cancer. However, there is a very small increased risk of deep vein thrombosis (DVT). A small minority of women experience uncomfortable leg cramps and swelling of the ankles.
Calcitonin
Calcitonin is not often used by specialists in Britain. Its action is generally considered to be weaker than that of other treatments. For regular use it comes in an inhaled form as a nasal spray; for short-term use it is also available by injection which is given subcutaneously. Some doctors will use either the injections or the nasal spray in a short course lasting a few weeks to help to reduce pain following a vertebral fracture.
Strontium ranelate
Strontium is taken as a powder (strontium ranelate) which you mix with water. It is taken once daily, at least 2 hours before or after food. Most people find it convenient to take it 2 hours after the evening meal and before going to bed. Some people taking strontium develop mild diarrhoea which can be sufficiently troublesome to stop longer-term use. Occasionally strontium causes nausea or rashes and there is a small increased risk of DVT.
Calcitriol
Calcitriol improves calcium absorption from the intestine. It is taken as a tablet twice daily. Regular (though infrequent) checks on calcium levels are recommended.
Hormone replacement therapy (HRT)
For many years, hormone replacement therapy (HRT) was the only established medication for the prevention and treatment of osteoporosis. However, its use was always limited by side-effects, including a small increased risk of breast and ovarian cancer, DVT, heart attacks and strokes. The value of HRT has been further undermined by the introduction of other, non-hormonal treatments which appear safer. Accordingly, there is now a limited role for HRT in the management of osteoporosis. This is probably confined to short-term therapy for early post-menopausal women with increased fracture risk who have troublesome menopausal symptoms, as HRT is highly effective in relieving these symptoms.
Calcium and vitamin D
Part of the routine treatment for osteoporosis is to ensure adequate calcium and vitamin D intake. Usually, a calcium and vitamin D supplement is recommended for people receiving bisphosphonates and most other therapies for osteoporosis.
In some elderly women a daily combination of calcium 1200 mg and vitamin D 800 international units (20 micrograms) may be prescribed alone (without other drugs in combination) to reduce the risk of a broken hip.
How long will the treatment take to work?
Treatments for osteoporosis take time to work, because bone renewal is a slow process. Nonetheless, reduction in fracture risk is often evident after 6–12 months. It is important that you continue treatment as long as advised to do so by your doctor – the aim is to prevent fractures rather than to make you feel better in the short-term.
How do I know if the treatment is working?
Bone density may be measured following treatment, usually by scanning the spine and/or hips. Increasingly, special markers of bone turnover (bone formation and breakdown) are measured in the blood and urine. These give an earlier indication of response to treatment than bone density and changes are seen within 3–6 months. However, as yet they are not widely available.
Is any special monitoring required while on treatment?
You may have had a bone density scan prior to treatment, although this is not necessary for everyone. Your doctor may recommend subsequent monitoring, either by bone density scans or by bone markers where these can be performed. If you are taking HRT, regular checks of blood pressure and mammography (breast x-rays) will form part of the routine monitoring.
Are there any drug interactions?
There are rarely any reasons why you should avoid taking any additional medicines when receiving treatments for osteoporosis. However, you should discuss any new medications with your doctor before starting them.
Can I receive immunisations?
There is no reason why you should not receive immunisations while taking treatment for osteoporosis.
What about alcohol?
Excess alcohol intake is one of the risk factors which can lead to osteoporosis. Alcohol, however, is unlikely to interfere with any of the medications which you may be taking for the treatment of osteoporosis.
Are treatments safe during pregnancy or when breastfeeding?
Osteoporosis is usually, but not only, a condition of older people. Most of the drugs are licensed for use in post-menopausal women. However, there are instances where younger women require treatment.
Bisphosphonates cross the placenta and so may pass to the unborn child. Once attached to bone they can remain there for long periods, often years. Therefore wherever possible bisphosphonates should be avoided in women of childbearing age, although in practice this is not always feasible. Similar concerns apply to breastfeeding because bisphosphonates will be transferred to the baby, although only in small amounts. Therefore you should not breastfeed while taking bisphosphonates.
The effects of teriparatide/parathyroid hormone in pregnancy and breastfeeding are not established. However, as the use of teriparatide/parathyroid hormone is confined to the most severe forms of progressive osteoporosis, they are unlikely to be recommended in young women.
Raloxifene is not appropriate for use in pre-menopausal women. Strontium and raloxifene slightly increase the risk of DVT which is already increased in pregnancy. There is no information regarding the effect of strontium on foetal development and it should therefore be avoided in pregnancy wherever possible, and you should not breastfeed while taking strontium.
As always the risks and benefits of treatment need to be considered carefully and discussed with your doctor.
Further information
Depending on your place of residence there might be a local osteoporosis unit near you with an open access helpline. Ask your doctor or rheumatology nurse for details.
If you would like any further information about drugs for osteoporosis, or if you have any concerns about your treatment, you should discuss this with your doctor, rheumatology nurse or pharmacist.
Remember to keep all medicines out of reach of children.
PLEASE NOTE: We have made every effort to ensure that the content of this information sheet is correct at time of going to press, but remember that information about drugs may change. This sheet does not list all the uses and side-effects associated with this drug. For full details please see the drug information leaflet which comes with your medicine. Your doctor will assess your medical circumstances and draw your attention to any information or side-effects which may be relevant in your particular case.
