BMJ Group Medical Reference
Beta-blockers are medicines that are mainly used for people with heart problems. Sometimes they are used to help children who get a lot of bad migraines.
The beta-blocker that's used most often for migraines is called propranolol. Its brand name is Inderal. You take it as tablets or a liquid. You need to take it every day, usually two or three times a day.
We don't know if these drugs can help prevent migraines for children, because different studies have had different results. One small study looked at 32 children. The children who took propranolol all said it helped them. But in another study, researchers found that propranolol actually made people's migraines worse.  People who took propranolol had headaches that lasted about three hours longer, on average.
And another study found that propranolol didn't make any difference to the number of migraines children had. 
Beta-blockers can cause side effects. In one study, about 1 in 5 children and teenagers had trouble sleeping. 
Beta-blockers can cause breathing problems in some people. They're not recommended for anyone with lung problems, so children with asthma shouldn't take these drugs. 
Asthma is a disease of the lungs. It makes you wheeze, cough and feel short of breath. Asthma attacks are caused by inflammation and narrowing of your airways, which makes it hard for air to pass in and out of your lungs.
These drugs work by blocking the effects of certain chemicals produced by your body (such as adrenaline). Beta-blockers slow your heart rate and improve the beating of your heart. They are often used in people with angina or heart failure.
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