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 bone metastases (cancer that has spread to the bones) in people who have breast cancer. They 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 bone fractures.

The bisphosphonates that are usually prescribed for this are: alendronate (the most used one), etidronate, ibandronate, and risedronate. They come in various different brand names.

What is osteoporosis?

Bone is made of collagen fibres (tough, elastic fibres) and minerals (gritty, hard material). It is a living tissue and contains cells that make, mould and resorb (take back up) bone. Initially, as you grow, bone formation exceeds bone resorption. But, as you get older, this reverses and, after about the age of 45, 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 a lot of bone loss, then you have osteoporosis. If you have osteoporosis, your bones can break more easily than normal, especially if you have an injury such as a fall. Fractures or breaks 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 on your bone-making cells. They slow down how quickly you lose bone. They can help to restore some lost bone and help to prevent further bone loss. People who take a bisphosphonate are less likely to break or fracture a bone.

When are bisphosphonates usually prescribed?

Your doctor may prescribe a bisphosphonate if you:

  • Have osteoporosis and have already had a bone fracture or break (they 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. Examples of people who are at risk of getting a fracture include: women who have had the menopause, people who drink more than four units of alcohol each day, anyone with one parent who has had a hip fracture, or anyone who is very thin.
  • Take long courses (more than three months) of steroids (corticosteroids) – for example, prednisolone tablets, or repeated short courses of high-dose steroids. A common side-effect of taking steroids is to cause osteoporosis. It is thought that 3-5 people out of 10 who take steroids for a long time develop a bone fracture.

How well/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 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. Many 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 the rest of their lives. Your doctor will advise.

Which is the best one?

All of the bisphosphonates lower your chance of having a fracture but no one is exactly sure which bisphosphonate works the best. But 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 your oesophagus (the tube that takes food into 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 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. Your doctor will advise which one is right 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 nausea (feeling sick), indigestion, mild inflammation of the oesophagus (the tube that takes food into your stomach), mild inflammation of the stomach, and abdominal pain. 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.

Less commonly, some people experience: inflammation of the oesophagus, oesophageal ulcers, and narrowing of the oesophagus.

A rare side-effect is osteonecrosis of the jaw. This is when the jaw bone does not receive enough blood, the bone starts to weaken and die. You must stop taking bisphosphonates if this happens.

There have been very rare reports of bisphosphonates possibly causing cancer of the oesophagus, but no one knows for sure if this is true.

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. See the leaflet that comes with your particular brand for full list of possible side-effects and cautions.

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 hypocalcaemia (low amounts of calcium in your blood).
  • You have some conditions which affect your bone – for example, parathyroid dysfunction, or hypovitaminosis D.
  • 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.

Further help and information

The National Osteoporosis Society

Camerton, Bath, BA2 0PJ
Tel: 01761 471771/0845 130 3076, Web: www.nos.org.uk

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: http://yellowcard.mhra.gov.uk

The Yellow Card Scheme is used to make pharmacists, doctors and nurses aware of any new side-effects that your medicines 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.
  • Information about 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.

References and Disclaimer | Provide feedback


  • British National Formulary; 62nd Edition (Sep 2011) British Medical Association and Royal Pharmaceutical Society of Great Britain, London (link to current BNF)
  • Osteoporosis – secondary prevention including strontium ranelate, NICE Technology Appraisal Guideline (January 2011); Alendronate, etidronate, risedronate, raloxifene, strontium ranelate and teriparatide for the secondary prevention of osteoporotic fragility fractures in postmenopausal women
  • Osteoporosis – prevention of fragility fractures, Prodigy (December 2010)
  • Management of osteoporosis in a post-menopausal woman, MeReC Bulletin Vol 20, No 01, 2010


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