Beta blockers is the name for a class of drugs that inhibit the hormone adrenalin and the neurotransmitter noradrenalin.

They work mainly by slowing down the heart. They do this by blocking the action of hormones like adrenaline.^[1]

Adrenalin is mainly released in stress situations; blocking its pathway will lead to lowering the heart rate,^[1] and blood pressure.^[1]

Beta blockers usually come as tablets.^[1] They are prescription-only medicines, which means they can only be prescribed by a GP or another suitably qualified healthcare professional.^[1]

Commonly used beta blockers

• atenolol (also called Tenormin)
• bisoprolol (also called Cardicor or Emcor)
• carvedilol
• labetalol (also called Trandate)
• metoprolol (also called Betaloc or Lopresor)
• propranolol (also called Inderal or Angilol)
• sotalol

Uses

Beta blockers may be used to treat:^[1]

• angina – chest pain caused by narrowing of the arteries supplying the heart
• heart failure – failure of the heart to pump enough blood around the body
• atrial fibrillation – irregular heartbeat
• heart attack – an emergency where the blood supply to the heart is suddenly blocked
• high blood pressure – when other medicines have been tried, or in addition to other medicines

Less commonly, beta blockers are used to prevent migraine or treat:^[1]

• an overactive thyroid (hyperthyroidism)
• anxiety
• tremor
• glaucoma – as eyedrops

There are several types of beta blocker, and each one has its own characteristics. The type prescribed for will depend on the patients health condition.^[1]

Who can take beta blockers

Beta blockers are not suitable for everyone. A doctor should know if:^[1]

• uncontrolled heart failure occurs
• there has been an allergic reaction to a beta blocker or any other medicine in the past
• there is low blood pressure or certain conditions that affect the rhythm of the heart
• if there is metabolic acidosis – when there's too much acid in the blood
• there is lung disease or asthma

Tell the doctor if pregnancy is a possibility in the future, or are already pregnant or breastfeeding.^[1] It's important not to stop taking beta blockers without seeking the doctor's advice. In some cases, suddenly stopping the medicine may make a health condition worse.^[1]

Side effects

Most people taking beta blockers have either no or very mild side effects that become less troublesome with time. But contact the GP if there are symptoms that are bothering or last more than a few days.^[1]

Side effects commonly reported by people taking beta blockers include:^[1]

• feeling tired, dizzy or lightheaded (these can be signs of a slow heart rate)
• cold fingers or toes (beta blockers may affect blood supply to the hands and feet)
• difficulties sleeping or nightmares
• difficulty getting an erection or other difficulties with sex
• feeling sick

It happens rarely, but some people have serious side effects when taking beta blockers. Tell a doctor straight away if there is:^[1]

• dyspnea and a cough that gets worse with exercise (like walking up stairs), swollen ankles or legs, or an irregular heartbeat – these can be signs of heart problems
• shortness of breath (dyspnoea), wheezing and tightening of the chest – these can be signs of lung problems
• yellowish skin or whites of the eyes turn yellow, although this may be less obvious on brown or black skin – these can be signs of liver problems

These are not all the side effects of beta blockers.^[1] For a full list, see the leaflet inside the medicine packet.

Related pages

• Hyperthyroidism
• Statin
• Liver and Glaucoma