What are the pros and cons of medication to prevent bone fractures?

Bisphosphonates can reduce the risk of osteoporosis-related bone fractures. Because they have side effects, it is worth weighing the pros and cons before deciding whether to take them.

A hip fracture (femoral neck fracture) can have especially drastic consequences. For this reason, it makes sense to separately consider the risk of a femoral neck fracture and the risk of other fractures such as wrist fractures.

The following illustrations show what women with osteoporosis can expect from treatment with these medications. The numbers refer to a time period of three years. Over that time, bisphosphonates prevent

• a bone fracture in about 4 out of 100 women, and
• a femoral neck fracture in about 1 out of 100 women.

Four bisphosphonates have been approved for the treatment of osteoporosis:

• Alendronate
• Ibandronate
• Risedronate
• Zoledronic acid

They can be taken as tablets or given as an infusion (a drip).

The medications may irritate the food pipe when swallowed. Because of this, it's important to do the following:

• Take the tablets first thing in the morning with a glass of water (200 ml, not mineral water with a lot of calcium in it). Do not crush or chew them. Swallow them quite quickly.
• Then stay upright for at least 30 minutes – in other words, sitting or standing – and do not lie down.
• Do not swallow other medications, food, or drinks until at least 30 minutes after taking the tablet.

Taking the medication in this way also ensures that it is absorbed by the bowel.

There are differences in how the various medications are used, though:

• Alendronate: once a day or once a week as a tablet or an effervescent (fizzy) tablet to be dissolved in water
• Ibandronate: once a month as a tablet or every three months through a drip
• Risedronate: as a tablet taken daily, weekly or monthly, depending on the dosage
• Zoledronic acid: once a year through a drip

Alendronate is by far the most commonly used bisphosphonate.

Bisphosphonates are usually well tolerated. Their potential side effects mainly depend on whether they are taken as tablets or given as an infusion (through a drip).

Tablets sometimes lead to gastrointestinal (stomach and bowel) problems such as heartburn, nausea, diarrhea or constipation. They can also irritate the food pipe. Infusions might then be better for people who already have problems such as heartburn or reflux. People who have other health problems affecting their food pipe, stomach or bowel are generally advised not to take the tablets.

Bisphosphonate infusions can lead to flu-like symptoms in the first few days after they are given – especially the first time they are used. Fever-reducing medications such as acetaminophen (paracetamol) or ibuprofen can relieve these symptoms. They are then taken for up to three days.

In very rare cases, bisphosphonates cause the jaw bone – or parts of the jaw bone – to die (necrosis). It is estimated that up to 3 out of 10,000 women could develop this side effect after many years of treatment. Necrosis of the jaw bone is thought to be more likely in women who have cancer and those who are given the medication as an infusion.

Before starting treatment with bisphosphonates, your doctor will check that there are no medical reasons why you shouldn't have it. They might ask whether you have other health problems, whether you are taking any other medication, and whether your jaws and teeth are healthy. Various blood levels will also be checked to make sure your kidneys are working well and to rule out any medical problems that mean you can't have the treatment.

People who take bisphosphonates should also tell their dentist about it. It might make sense to wait until after any jaw or tooth treatments before taking this medication.

It is not normally necessary to check bone density during the treatment. On the one hand, the protection offered by the medication doesn't only depend on bone density. On the other, bone density scans expose you to radiation. There is no proof that regular bone density check-ups have any advantages during treatment with bisphosphonates.

Other medications sometimes used in the treatment of osteoporosis include denosumab, raloxifene and teriparatide. But they are only used if bisphosphonates are not an option.

Denosumab is injected under the skin every six months. It can reduce the risk of bone fractures, and is also suitable for people who have renal insufficiency (kidney problems). But there are safety concerns about this drug. Some studies found that bone density decreased a lot when people stopped using denosumab, which increases the risk of fractures. In very rare cases, denosumab can also cause parts of the jaw bone to die.

Raloxifene is very rarely used. One reason for this is because it increases the risk of thrombosis and fatal stroke.

Teriparatide is also very rarely used. It has not been shown to prevent hip fractures. And it has only been approved for up to two years of treatment.

Whether or not to use osteoporosis medication is ultimately a personal decision: Some people want to avoid breaking a bone at all costs and decide to use medication. Others decide not to because they don't want the burden of using the medication regularly and the possible side effects.

It is not always easy to make a decision, but there is no need to rush into anything. It might help to talk to your doctor about the pros and cons of the treatment. Your family doctor knows your personal and medical situation and is a good first point of contact.

Risk calculators can help you to weigh the pros and cons. These are special computer programs that use information about your personal risk factors to estimate the likelihood that you will break a bone in the coming years. Good risk calculators give you a score, which helps to make an informed decision. The "FRAX Calculator" is one example of an internationally used risk calculator that estimates the risk of fractures.