Inderal LA

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How does it work?

Inderal LA and Half Inderal LA sustained release capsules contain the active ingredient propranolol hydrochloride, which is a type of medicine called a beta-blocker. (NB. Propranolol is also available without a brand name, ie as the generic medicine.) Beta-blockers work by blocking beta receptors that are found in various parts of the body. Blocking beta receptors prevents the action of two chemicals, called noradrenaline and adrenaline, which are produced naturally by the body. These are often referred to as the 'fight or flight' chemicals, because they are responsible for the body's reaction to stressful situations.

Beta receptors are found in the heart. When they are blocked by propranolol the heart is made to beat more slowly and with less force. This reduces the pressure at which the blood is pumped out of the heart and around the body. This in turn reduces blood pressure, which means that propranolol can be used to treat high blood pressure. It also reduces the energy used by the heart to pump blood around the body, and so reduces the heart's need for oxygen, which means it can also be used in the management of angina.

Angina is chest pain that occurs because the heart does not get enough oxygen to meet demand, such as when doing exercise. Propranolol reduces the workload of the heart and so decreases its demand for oxygen. This helps to prevent attacks of angina.

In addition to these heart related uses, propranolol can also be used to control symptoms that are associated with anxiety or an overactive thyroid gland (thyrotoxicosis), such as a racing pulse, sweating and tremor. This is because it blocks the effects of adrenaline.

Propranolol is also used to prevent migraine, although it is not fully understood how propranolol works in this area.

Inderal LA and Half Inderal LA are long-acting forms of propranolol. This means they only need to be taken once a day.

What is it used for?

- High blood pressure
- Angina pectoris
- Anxiety
- Tremor without underlying cause (essential tremor)
- Management of thyrotoxicosis and thyrotoxic crisis
- Preventing bleeding from varicose veins in the foodpipe (oesophageal varices) that occur due to high blood pressure in the vein taking bood from the gut to the liver (portal hypertension) - usually a result of liver cirrhosis
- Prevention of migraines

Warning!

- You should not stop taking this medicine suddenly, particularly if you have ischaemic heart disease (inadequate flow of blood to the heart, eg angina). When treatment with this medicine is stopped it should be done gradually, usually over one to two weeks, following the instructions given by your doctor.
- This medicine may occasionally cause fatigue and dizziness. You should take care when performing potentially hazardous activites, such as driving or operating machinery, until you know how this medicine affects you and are sure you can perform such activities safely.
- This medicine may mask the symptoms of low blood sugar such as increased heart rate, tremor and nausea. People with diabetes should carefully monitor their blood sugar.

Use with caution in

- Elderly people
- Decreased kidney function
- Decreased liver function
- Diabetes
- Heart failure
- Slowed conduction of electrical messages between the chambers of the heart (1st degree heart block)
- High pressure in the vein taking blood from the gut to the liver
- Liver cirrhosis
- Conditions involving poor blood circulation in the arteries of the extremities, eg Raynaud's disease
- Psoriasis
- History of severe allergic reactions (anaphylaxis)

Not to be used in

- History of asthma
- History of breathing difficulties due to a narrowing of the airways (bronchospasm)
- A problem common in the elderly, related to poor control of the working of the heart (sick sinus syndrome)
- Failure of the heart to maintain adequate circulation of blood (cardiogenic shock)
- A severe form of angina pectoris, not caused by exertion
- Uncontrolled heart failure
- Serious defect in the heart's electrical message pathways resulting in decreased function of the heart (2nd or 3rd degree heart block)
- Slow heart rate (bradycardia)
- Low blood pressure (hypotension)
- Conditions involving severe disturbance of blood circulation in the arteries of the extremities
- Increased acid levels in the blood (metabolic acidosis)
- Prolonged fasting
- Untreated tumour of the adrenal gland (phaeochromocytoma)

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

- This medicine may have adverse effects on an unborn child and is not recommended for use in pregnancy unless considered essential by your doctor. Seek medical advice from your doctor.
- This medicine may pass into breast milk. It is recommended that women who need to take this medicine do not breastfeed their infants. Discuss this with your doctor.

Label warnings

- This medicine should be swallowed whole, not chewed.
- Do not stop taking this medication except on your doctor's advice.

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