Study looks at side effects of blood pressure medicine
Publication Date:14/04/2008
A common type of blood pressure medicine may weaken men's bones, according to a new study. But we don't know how important the effect might be. It may not be enough to increase the risk of breaking a bone.
What do we know already?
Many older people take a type of medicine called loop diuretics. These drugs are used to treat high blood pressure and heart failure. The most commonly used loop diuretic is called furosemide (one brand name is Lasix). Other loop diuretics include bumetanide (Burinex) and torasemide (Torem). They work well, but they do have side effects.
One of the side effects is to increase the amount of calcium that goes out of your body in your urine. Calcium is used in the body to build healthy bones. There is a lot of calcium in dairy products like milk and yoghurt.
Everyone's bones get weaker as they get older. Doctors can measure bone mineral density using a machine called a DXA scanner. Bone mineral density is a measure of how much calcium and other minerals you have in your bones, keeping them strong. If you have weak bones, you have more chance of breaking a bone, especially if you have a fall.
Researchers were concerned that losing calcium from your body could affect the strength of your bones. So, they measured the bone strength of several thousand men, to see what effect taking diuretics had.
What does the new study say?
The bones of the men who were taking diuretics throughout the four-year study got weaker than the men who weren't taking diuretics.
The researchers measured the bone strength at the hips of more than 3,000 men aged 65 or older. Only 84 of these men were taking diuretics continually throughout the study. Another 181 men took them at some point.
Everyone in the study lost some bone strength. After taking account of other things that can affect bone strength (such as exercise and diet), the researchers found:
- Men not using diuretics lost 0.3 percent of bone strength each year
- Men using diuretics at some point lost 0.6 percent of bone strength each year
- Men using diuretics all through the study lost 0.8 percent of bone strength each year.
But the study didn't look at whether the men taking diuretics had more falls or broke more bones than the men who didn't take diuretics.
Where does the study come from?
The study was carried out by researchers at several US institutions, including the University of Minnesota, Minneapolis, and Griffin Hospital, Connecticut. It was published in the Archives of Internal Medicine, a medical journal owned by the American Medical Association.
How reliable are the findings?
The study was well carried out. However, only 84 out of more than 3,000 men in the study were taking loop diuretics, which means the findings are harder to rely on.
Also, men taking diuretics were more likely to be older or to have other illnesses, and were less likely to be very active. All these things can affect your bone strength. The researchers tried to take account of these things when they calculated the results. But this type of study can't prove that the diuretics were definitely responsible for the weaker bones.
What does this mean for me?
If you're taking loop diuretics, there's no need to panic. The changes in bone strength in the study happened slowly, and we don't know for certain that the changes were big enough to make a difference. This study doesn't show that taking loop diuretics makes you more likely to break a bone.
Other blood pressure medicines are not affected by this study. Another group of diuretics, called thiazides, are also not affected.
What should I do now?
If you are concerned about your blood pressure medicine, make an appointment to discuss it with your GP or with a pharmacist. Don't stop taking your medicine without talking to your doctor first. Loop diuretics work well for people with high blood pressure and heart failure. You might be at risk of a heart attack or stroke if you stop your medicine.
From:
Lim LS, Fink HA, Kuskowski MA, et al. Loop diuretic use and increased rates of hip bone loss in older men. Archives of Internal Medicine. 2008; 168: 735-740.
To find out more, see our information on high blood pressure and heart failure.
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© BMJ Publishing Group Limited ("BMJ Group") 2007. All rights reserved
This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.
