Bisphosphonates are a group of medicines used to treat conditions that affect your bones. They are mainly used to prevent broken bones (fractures) in people who have weak bones. It usually takes between 6-12 months for bisphosphonates to work, and they are normally taken for at least five years (some people take them for much longer). They are always taken with a full glass of water on an empty stomach, and you must stand or sit upright for 30 minutes after you take them. You need to wait between 30 minutes and 2 hours before you eat any food or have any other drinks. Some people are given calcium (if they don't have enough in their diet) and vitamin D to take (at a different time to the bisphosphonate) when they are prescribed a bisphosphonate.
What are bisphosphonates?
Bisphosphonates are a group of medicines used to treat conditions that affect your bones. Examples of these conditions include osteoporosis, Paget's disease of bone, and cancer that has spread to the bones (bone metastases). Bisphosphonates are also used to treat very high amounts of calcium in the blood in people who have cancer and are very ill.
There are quite a few bisphosphonates available for the different conditions.
The rest of this leaflet is only about bisphosphonates that your doctor may prescribe for osteoporosis and to prevent broken bones (fractures).
What is osteoporosis?
Our bones are made of tough elastic fibres, calcium and other minerals. Bone is a living tissue and changes throughout your life. Old bone is broken down by cells called osteoclasts. It is continually replaced by cells called osteoblasts, which build bone. Initially, as you grow, bone formation happens faster than bone loss. But, as you get older, this reverses and, after about the age of 35, you start to lose a certain amount of bone material. Your bones become less dense and less strong. The amount of bone loss can vary. If you have too much bone loss then you have bones which are weaker. This is called osteoporosis. If you have osteoporosis, your bones can break (fracture) more easily than normal, especially if you have an injury such as a fall. Fractures are more likely in the hip, spine or wrist.
If you have a milder degree of bone loss, this is known as osteopenia.
For more information see separate leaflet called Osteoporosis.
How do bisphosphonates work?
Bisphosphonates work by slowing down the cells which break down bone (osteoclasts). Therefore they slow down bone loss, allowing the bone building cells (osteoblasts) to work more effectively. They can help to strengthen bone and help to prevent it getting any weaker. People who take a bisphosphonate are less likely to break (fracture) a bone.
Who should have bisphosphonates?
Your doctor may prescribe a bisphosphonate if you:
- Have osteoporosis and have already had a broken bone (fracture). Bisphosphonates help to prevent any further bone fractures.
- Have a low bone density and your doctor thinks you are at risk of getting a bone fracture. Factors that can increase your risk of getting a fracture include:
- Being female and past your menopause.
- Having had your menopause very early.
- Drinking more than three units of alcohol each day.
- Having a family history of osteoporosis or a parent who has had a hip fracture.
- Being very thin.
- Having rheumatoid arthritis.
- Having type 1 diabetes mellitus.
- Having hyperthyroidism or hyperparathyroidism.
- Having a disorder which means your guts do not absorb nutrients as well as they should, such as coeliac disease, Crohn's disease or ulcerative colitis.
- Take long courses (more than three months) of steroids (corticosteroids) - for example, prednisolone tablets. You may also be prescribed bisphosphonates if you take repeated short courses of high-dose steroids. A common side-effect of taking steroids is to cause osteoporosis.
How quickly do bisphosphonates work?
It takes several months for bisphosphonates to work. Usually there is an increase in bone density 6-12 months after you start taking one. This then helps to prevent breaks (fractures) of the spine, the hip, and other bones such as the wrist. But you can still have a fracture while you are taking a bisphosphonate - they do not totally reduce your risk. They need to be taken for a long time to see the full effect. For most bisphosphonates, the bone-strengthening effect diminishes a few months after you stop taking them. However, the effect alendronate has had may continue for 3-5 years after you stop taking it.
What is the usual length of treatment?
Not everyone agrees on how long bisphosphonates should be taken for. However, most experts agree that they need to be taken for a number of years to see the full effect. Most doctors recommend that a bisphosphonate be taken for at least five years. After this they will review you to see if you still need to take it. You may not need to continue taking a bisphosphonate. However, some people need to take a bisphosphonate for longer. Your doctor will advise. There is some evidence from studies that bisphosphonates keep working on the bone for a few years after the medicine has been stopped. It may also be that taking them for longer than five years does more harm than good. More studies are being done to find out exactly what should be recommended in terms of how long bisphosphonates should be taken.
Which is the best one?
All bisphosphonates lower your chance of having a broken bone (fracture) but no one is exactly sure which bisphosphonate works the best. However, alendronate and risedronate are thought to work slightly better than etidronate.
Alendronate and risedronate are prescribed most often. They are older bisphosphonates and can be taken once a week instead of every day. Many doctors will prescribe alendronate first. If this does not suit you or causes problems, your doctor may ask if you would like to try another bisphosphonate (usually risedronate).
Etidronate is less popular because it is more complicated to take and it may not work quite as well as alendronate or risedronate. The tablets are taken in a 90-day cycle (14 days of etidronate, followed by 76 days of calcium).
Ibandronate is a newer bisphosphonate and is taken once a month.
How to take bisphosphonates
Bisphosphonates are taken either once a day, once a week (on the same day of the week), or once a month (on the same day of the month), depending on the one prescribed. Most people take their bisphosphonate first thing in the morning before they eat or drink anything. If you take a bisphosphonate with food, or drinks other than water, only a small amount of the medicine is absorbed.
You need to wait between 30 minutes and 2 hours before eating or drinking anything (other than water). The information leaflet that comes with your tablets will tell you exactly how long you should wait.
You need to swallow the tablet with a full glass of water and sit upright for 30 minutes afterwards. This is because bisphosphonates can irritate the upper part of your gullet (oesophagus - the tube that takes food and drink from your mouth to your stomach.)
When taking bisphosphonates
Some important considerations are:
- What to do if you forget to take your tablets.
- Have regular dental check-ups.
- What to do if you have heartburn or difficulty swallowing.
- Take calcium and vitamin D tablets.
- Do not take certain other medicines.
What to do if you forget to take your tablets
- If you are taking a once-a-day bisphosphonate: skip the missed tablet for that day and continue taking them as usual the next day.
- If you are taking a once-a-week bisphosphonate: take the missed tablet when you remember and take the next tablet when it is normally taken. Do not take more than two tablets on the same day.
- If you are taking a once-a-month bisphosphonate and you are due to take your tablet within the next seven days, then do not take another tablet. Take another tablet on the day you are next due to take one.
- If you are taking a once-a-month bisphosphonate and you are due to take your next tablet in more than seven days, then take the tablet when you remember (in the morning). Do not take two tablets within the same week.
Regular dental check-ups
You must tell your dentist if you are taking a bisphosphonate. You will need to have regular dental check-ups. This is because there is a very small chance that you will get osteonecrosis of the jaw. This condition is when the jaw bone does not receive enough blood and the bone starts to weaken and die. It is usually painful, but not always. In most people, this goes away after you have stopped taking your medicine.
Heartburn or difficulty swallowing
Bisphosphonates can sometimes cause difficulty swallowing, pain when you swallow, chest pain, or new/worsened heartburn. You must stop taking the bisphosphonate and speak to your doctor if you have any of these problems. Your doctor may consider prescribing a different bisphosphonate or a different type of medicine to help prevent broken bones (fractures).
Calcium and vitamin D
You need calcium and vitamin D to make bone. Many doctors will also prescribe calcium and vitamin D if you take a bisphosphonate. This is in order to make sure there is enough calcium and vitamin D in your body. There are quite a few calcium and vitamin D preparations. They include: a chewable tablet, an effervescent tablet, or a sachet. They can be prescribed as a combination of the two, just calcium, or just vitamin D. Your doctor will advise which one is right for you. Your doctor will ask about your diet. If you are already having enough calcium in your diet, you should not take calcium supplements as well. This is because too much calcium may be harmful for you. Calcium and vitamin D are normally taken every day (at a different time to the bisphosphonate).
Taking other medicines
Bisphosphonates sometimes react with other medicines that you may take. So, make sure your doctor knows of any other medicines that you are taking, including ones that you have bought rather than been prescribed. Always check with your pharmacist before you buy any painkillers from the pharmacy or supermarket. Some painkillers - for example, ibuprofen and aspirin - can irritate your oesophagus if you take them with a bisphosphonate.
What are the possible side-effects?
The most common side-effects of bisphosphonates are feeling sick (nausea), indigestion and heartburn (dyspepsia), tummy (abdominal) pain, diarrhoea or constipation. These side-effects usually happen in the first month of treatment but usually go away after this.
Other common side-effects are joint, and/or muscle pain (usually not severe). This pain can happen a few days or a few months after you first start treatment. This pain normally goes away after you stop taking a bisphosphonate. A full list of possible side-effects (each of which will only happen to a few people) is included in the leaflet which comes with the medicine.
Less commonly some people experience more serious side-effects to their oesophagus. The oesophagus is the upper part of the digestive system, the food pipe that carries food and drink from your mouth to your stomach. Sometimes bisphosphonates can cause inflammation or ulcers of the oesophagus, or a narrowing of the oesophagus. Taking the medicine carefully according to the instructions makes these side-effects less likely. As mentioned above, if you get any symptoms such as difficulty or pain swallowing, worsening heartburn, or chest pain, you should stop the tablets and see your doctor. There have been very rare reports of bisphosphonates possibly causing cancer of the oesophagus, but there is no definite evidence for this currently.
A rare side-effect is osteonecrosis of the jaw. This occurs when the jaw bone does not receive enough blood, the bone starts to weaken and die. You must stop taking bisphosphonates if this happens.
These medicines sometimes react with other medicines that you may take. So, make sure your doctor knows of any other medicines that you are taking, including ones that you have bought rather than been prescribed.
Can I buy bisphosphonates?
You cannot buy bisphosphonates. They are only available from your chemist, with a doctor's prescription.
Who cannot take bisphosphonates?
You cannot take a bisphosphonate if:
- You have low calcium levels in your blood (hypocalcaemia).
- You have uncorrected vitamin D deficiency.
- You are pregnant or breast-feeding.
- Your kidneys do not work very well.
- You cannot sit upright or stand for 30 minutes after you have taken the tablet.
- You have structural problems with your oesophagus which slows down the length of time it takes for the bisphosphonate to reach your stomach. Examples of these include: a narrowing of the oesophagus, or Barrett's oesophagus.
How to use the Yellow Card Scheme
If you think you have had a side-effect to one of your medicines you can report this on the Yellow Card Scheme. You can do this online at the following web address: www.mhra.gov.uk/yellowcard.
The Yellow Card Scheme is used to make pharmacists, doctors and nurses aware of any new side-effects that medicines or any other healthcare products may have caused. If you wish to report a side-effect, you will need to provide basic information about:
- The side-effect.
- The name of the medicine which you think caused it.
- The person who had the side-effect.
- Your contact details as the reporter of the side-effect.
It is helpful if you have your medication - and/or the leaflet that came with it - with you while you fill out the report.
What else can I do to keep my bones strong?
There are other lifestyle measures which can help keep bones strong, as well as taking bisphosphonates. These include:
- Regular exercise. Exercise which helps your bones needs to be weight-bearing exercise. This includes jogging, skipping, brisk walking, dancing, netball and tennis, amongst many other options.
- Stopping smoking.
- Not drinking more than three units per day of alcohol.
- Eating a diet rich in calcium.
- Safe sun exposure, improving your vitamin D levels. See the separate leaflet Sun and Health for details.
Dr Mary Harding
Dr Jacqueline Payne