Epilepsy, osteoporosis and osteomalacia

Last updated 16 May 2011, review date due 16 May 2013

In this section

Introduction
Epilepsy, osteoporosis and osteomalacia
Possible causes of osteoporosis and osteomalacia in people with epilepsy
Risk of broken bones and fractures for people with epilepsy
Diagnosing osteoporosis and osteomalacia
Treatment of osteoporosis and osteomalacia
Where you can get more information about osteoporosis/osteomalacia, including treatment information

This information was written by Epilepsy Action’s advice and information team with guidance and input from people living with epilepsy and medical experts.

Our thanks

Epilepsy Action wishes to thank Lesley McCoy, epilepsy specialist nurse, and the National Osteoporosis Society, UK, for reviewing this information.

Introduction

This web page gives information about why some people with epilepsy may develop bone diseases due to their anti-epileptic drugs. These bone diseases are osteoporosis and osteomalacia. It also tells you where you can get help.

Epilepsy, osteoporosis and osteomalacia

Epilepsy is a tendency to have recurrent seizures. To control seizures people with epilepsy are prescribed anti-epileptic drugs (AEDs). Some AEDs can make some people more likely to develop osteoporosis and osteomalacia.

What is osteoporosis?

Osteoporosis is a disease that causes the bones to become fragile. This results in a loss of bone density (when the bones become porous) and increases the risk of bone fractures.

What is osteomalacia?

Osteomalacia is a disease that softens the bones causing muscle weakness and bone pain. It can also increase the risk of bone fractures.

Possible causes of osteoporosis and osteomalacia in people with epilepsy

Research has found that taking some anti-epileptic drugs (AEDs) long term can increase the risk of osteoporosis and osteomalacia. However, in some cases a reduction in bone density has been found during the first one to five years of taking some AEDs. These AEDs are carbamazepine, primidone, phenobarbital, phenytoin, topiramate and sodium valproate.

What seems to happen is that these AEDs can reduce the body's vitamin D level. Low vitamin D levels can cause a loss of bone density or softening of the bones.

It’s not clear if there is a possible risk of osteoporosis or osteomalacia with the newer AEDs. More research is needed.

Risk of broken bones and fractures for people with epilepsy

People with epilepsy have a higher risk than average of broken bones and fractures. Here are some things that increase the risks.

Having a fall during a seizure
Taking anti-epileptic drugs such as carbamazepine, primidone, phenobarbital, phenytoin, topiramate and sodium valproate
Being a woman who has been through the menopause
Being an older men
Rarely going out in the sunshine
Being physically disabled

If anyone is concerned that they could be at risk of developing osteoporosis or osteomalacia, they could discuss it with their doctor.

Diagnosing osteoporosis and osteomalacia

The doctor will probably want to look at the person’s medical history. They should also consider any drugs their patient is taking, or have taken in the past.

The doctor may ask about diet, any family history of bone disorders, and suggest blood tests or X-rays. X-rays can show any cracks or fractures in the bones.

There is limited access to bone density scans in some parts of the UK. So, the doctor may be reluctant to make a referral. That is unless they consider their patient is at a particularly high risk of developing osteoporosis or osteomalacia.

It’s possible to have a bone density scan done privately or on the NHS. The doctor can arrange one, if there is a bone density scanner in the area.

Treatment of osteoporosis and osteomalacia

The doctor may prescribe a vitamin D supplement as a protection against developing osteoporosis. This is likely if the anti-epileptic drugs carbamazepine, primidone, phenobarbital, phenytoin, topiramate or sodium valproate, have been taken for a long time,

If osteomalacia is diagnosed, a prescription for a higher than usual dose of a vitamin D supplement will be given.

If osteoporosis is diagnosed, and there is no evidence of osteomalacia, an osteoporosis drug may be prescribed. Also, a calcium and vitamin D supplement may be prescribed.