Risedronate (risedronate sodium) is a type of medicine called a bisphosphonate. It helps your bones stay as strong as possible.

It can help if you have or are at risk of getting a health problem called osteoporosis. This is where your bones get weaker and more likely to break.

Osteoporosis can happen for many reasons, but you're more likely to get it if you're a woman who has been through the menopause or if you take steroids, such as prednisolone, for a long time. Some types of cancer treatment can also increase your risk of getting osteoporosis.

Risedronate can also help people who have Paget's disease of bone. This weakens your bones and can bend them out of shape.

Risedronate comes as tablets and is only available on prescription.

• Risedronate is good for your bones – it makes them stronger and less likely to break.
• Most people take it as a weekly tablet, but it may be taken daily.
• Take risedronate first thing in the morning, at least 30 minutes before you have anything to eat or drink and before you take any other medicines.
• It's important to look after your teeth and have regular dental check-ups while taking risedronate.
• Risedronate is also called by the brand names Actonel and Actonel Once a Week.

Risedronate can be taken by adults aged 18 and over. It's occasionally prescribed for children with osteoporosis.

Risedronate is not suitable for some people. To make sure it's safe for you, tell your doctor if you:

• have had an allergic reaction to risedronate or any other medicine in the past
• have digestive problems, problems swallowing or any problems with your food pipe
• cannot sit up or stand for at least 30 minutes
• have low calcium levels in your blood – taking risedronate could make them even lower
• have kidney problems
• have cancer, or are having chemotherapy or radiotherapy
• have problems with your teeth, or are waiting for dental treatment such as having a tooth out
• smoke or used to smoke – this may increase your risk of dental problems
• are pregnant or breastfeeding, or trying to get pregnant

Risedronate comes as a tablet that you take once a week, or as a tablet that you take once a day.

Follow your doctor's instructions about exactly how and when to take your medicine. If you're taking a weekly dose, you need to take your medicine on the same day each week, so choose a day that suits your routine.

How much will I take?

Paget's disease of bone – the usual dose for adults is 30mg, taken once a day

Osteoporosis the usual dose for most adults is 35mg taken once a week. You may prefer to take 5mg, once a day

How to take it

Risedronate works best when your stomach is empty, so your body can absorb it properly. It's important to take risedronate while you're sitting up or standing. Stay upright for 30 minutes after taking your medicine – you can be sitting, standing or walking.

Take your medicine first thing in the morning, when you get up. Take it on an empty stomach, at least 30 minutes before you have anything to eat or drink (other than plain tap water) and before you take any other medicines or supplements.

Swallow the tablet whole with a large glass of plain tap water (at least 120ml). Do not chew, break, crush or suck the tablet. Do not take it with mineral water.

It's important to follow the instructions for this medicine very carefully. If you do not, it may not work or it could irritate and damage your food pipe as you swallow it.

If you usually take risedronate once a day and you're unable to take your tablet in the morning, you can take it later in the day. However, it's important not to eat or drink anything (other than plain water) and not to take any other medicines or supplements by mouth either 2 hours before or 2 hours after taking the tablet.

What if I forget to take it?

It depends how often you're supposed to take risedronate. If you usually take it:

• once a day – take it later in the day following the instructions above about taking it on an empty stomach If this is not possible, then just take your next dose on the following day, in the morning

• once a week – wait until the next day and then take your medicine first thing in the morning. After this, go back to taking your weekly dose on your usual day

If you take riseodranoate once a week, some packaging has a space to mark the day of the week and the dates you take your tablets. This can help you remember to take your medicine on the right day.

Never take 2 doses to make up for a forgotten one.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

What if I take too much?

If you take an extra dose of:

• your 5mg daily or 35mg weekly tablet – it's unlikely to harm you. Drink a full glass of milk immediately and stay upright for at least 30 minutes
• your 30mg daily tablet – drink a full glass of milk immediately and stay upright for at least 30 minutes

If your child takes an extra dose, get them to drink a full glass of milk immediately. Contact their doctor straight away. Keep your child sitting up or standing for at least 30 minutes.

Do not make yourself or your child sick (vomit), as this may irritate your, or your child's, food pipe.

Like all medicines, risedronate can cause side effects in some people but many people have no side effects or only minor ones.

Common side effects

These common side effects happen in more than 1 in 100 people. Talk to your doctor or pharmacist if the side effects bother you or do not go away:

• constipation
• diarrhoea
• indigestion, bloating, stomach pain or wind
• feeling sick (nausea)
• headaches
• mild muscle, bone or joint pain

Serious side effects

Some people may have serious side effects when taking risedronate.

Tell a doctor straight away if you have:

• heartburn (or heartburn that gets worse), problems or pain when swallowing, or chest pain – these may be signs of ulcers in your food pipe. If this happens, stop taking risedronate and speak to a doctor
• a loose tooth, mouth sores, or swelling or pain in your mouth or jaw – contact your dentist as well as your doctor, as this could be a sign of damage to your jawbone
• pain, weakness or discomfort in your thigh, hip or groin – this happens rarely but may be an early sign of a broken thigh bone
• severe pain in the joints, muscles or bones
• ear pain, discharge from your ear or an ear infection – these can be signs of damage to the bones in your inner ear
• black or red poo – these can be signs of an ulcer or bleeding from your gut
• blurred vision, light sensitivity, painful or red eyes – these can be signs of swelling of the eye
• muscle cramps or spasms, a tingling sensation in your fingers or around your mouth – these can be symptoms of low calcium levels in your blood

Serious allergic reaction

In rare cases, risedronate may cause a serious allergic reaction (anaphylaxis).

These are not all the side effects of risedronate. For a full list, see the leaflet inside your medicine packet.

What to do about:

• Constipation – eat more high-fibre foods such as fresh fruit, vegetables and cereals, and drink plenty of water. Try to exercise more regularly, by going for a daily walk or run for example. If this does not help, talk to your pharmacist or doctor. Watch this short video about how to treat constipation.
• Diarrhoea – drink lots of fluids such as water or squash. Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee. Do not take any medicines to treat diarrhoea without speaking to a pharmacist or doctor.
• Indigestion, bloating or wind – make sure you follow the directions for taking risedronate carefully and sit or stand for at least 30 minutes after taking it. It might help to eat smaller and more frequent meals, eat and drink slowly, and exercise regularly. If the symptoms get worse, contact your doctor straight away.
• Feeling sick – stick to simple meals and do not eat rich or spicy food.
• Headaches, muscle or joint pain – make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller. Talk to your doctor if the pain lasts longer than a week or is severe.

Risedronate is not usually recommended during pregnancy. This is because there has not been enough research into its safety.

Risedronate and breastfeeding

Although it's generally safe to take this medicine while breastfeeding, it may not be suitable in some cases. Check with your doctor about what's best for you and your baby.

When taking risedronate, it's important to not take any other medicines at the same time. This is because they can interfere with how well your body absorbs risedronate and may stop it working properly.

If you take risedronate first thing in the morning, when you get up, wait for at least 30 minutes before taking your other medicines. If you take risedronate between meals or in the evening, wait at least 2 hours before taking your other medicines.

Tell your doctor if you're taking:

• supplements or multivitamins containing calcium, iron, magnesium or zinc
• antacids to relieve indigestion or heartburn
• laxatives containing magnesium such as Maalox, Mucogel or Milk of Magnesia
• cancer medicines such as bevacizumab and thalidomide, or if you're having chemotherapy or taking steroids such as prednisolone and dexamethasone – these may increase the risk of damage to your jawbone
• non-steroidal anti-inflammatories (NSAIDs) such as ibuprofen, which can increase the risk of irritating your food pipe, stomach or gut – taking low-dose aspirin is OK
• antibiotics such as gentamicin, amikacin, streptomycin or tobramycin – these can lower the calcium in your blood
• deferasirox, a medicine used to remove excess iron from the body – this may increase the risk of bleeding from your gut
• parathyroid hormone, a medicine used to treat hypoparathyroidism

Mixing risedronate with herbal remedies or supplements

There's very little information about taking herbal remedies and supplements with risedronate.