What is it used for?
How does it work?
This medicine contains two active ingredients, acebutolol and hydrochlorothiazide.
Acebutolol belongs to a group of medicines called beta-blockers, which block beta receptors in the heart, lungs and other organs of the body. Blocking these receptors prevents the action of two chemicals called noradrenaline and adrenaline that occur naturally in the body. These are often referred to as the 'fight or flight' chemicals as they are responsible for the body's reaction to stressful situations.
Blocking the beta receptors in the heart causes the heart to beat more slowly and with less force. This reduces the pressure at which blood is pumped out of the heart to the rest of the body. This is just one of the ways in which beta blockers help to reduce blood pressure, however the whole mechanism is not fully understood.
Hydrochlorothiazide is known as a thiazide diuretic. Thiazide diuretics act in the kidney to remove water from the blood into the urine, by causing an increase in the removal of salts such as potassium and sodium from the blood. This removal of salts causes water to be drawn out of the blood and into the kidneys, where it is then excreted in the urine.
Removing water from the blood decreases the volume of fluid circulating through the blood vessels. The drop in fluid volume results in a drop in the pressure of the fluid within the blood vessels, which helps to lower high blood pressure. It also decreases the effort required by the heart to pump blood around the body. This drop in fluid volume results in a drop in the pressure of the fluid within the blood vessels, thus lowering high blood pressure.
The combination of these two medicines is particularly useful in treating high blood pressure.
- 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.
- You should not suddenly stop taking this medicine unless your doctor tells you otherwise.
- It is recommended that individuals taking this medicine have their fluid and salt (electrolyte) balance monitored regularly.
- If you experience any of the following symptoms while taking this medicine you should inform your doctor promptly, so that the amount of fluids and salts in your body can be checked: thirst, lethargy, confusion, weakness, drowsiness, muscle cramps, scanty production of urine, abnormal heart rhythm, seizures, nausea and vomiting.
- As diuretics cause your kidneys to produce more urine, you may prefer to take this medicine in the morning rather than before going to bed, as this will reduce the likelihood of you needing to get up in the night to visit the toilet. Seek further advice from your doctor or pharmacist.
- If you should require local or general anaesthesia, it is important that you inform your anaesthetist you are taking this medicine.
Use with caution in
- Heart failure
- History of asthma or wheezing
- Low blood pressure (hypotension)
- Slow heart rate of less than 50 beats per minute (bradycardia)
- Type 2 (non-insulin dependent) diabetes
Not to be used in
- Chronic obstructive pulmonary disease (COPD)
- Defect of the heart's electrical message pathways resulting in decreased function of the heart (heart block)
- Failure of the heart to maintain adequate circulation of blood (cardiogenic shock)
- High blood uric acid level (hyperuricaemia)
- Severe kidney failure
- Severe liver failure
- Type 1 (insulin dependent) diabetes
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 should not be used in pregnancy. Seek medical advice from your doctor.
- This medicine passes into breast milk. It is recommended that mothers should avoid using this medicine while breastfeeding. Seek medical advice from your doctor.
- Do not stop taking this medication except on your doctor's advice.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
- Slower than normal heart beat (bradycardia)
- Blood disorders
- Disturbances of the gut such as diarrhoea, constipation, nausea, vomiting or abdominal pain
- Low blood pressure (hypotension)
- Breathing difficulties due to a narrowing of the airways (bronchospasm)
- Disturbances in the levels of chemical components (electrolytes) in the blood
The side effects listed above may not include all of the side effects reported by the drug's manufacturer.
For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.
How can this medicine affect other medicines?
When acebutolol is taken together with clonidine, there is a risk of a rebound increase in blood pressure when clonidine is stopped. The acebutolol should be stopped several days before slowly stopping the clonidine.
In diabetic patients, acebutolol can prolong the lowering of blood sugar (hypoglycaemia) caused by insulin or other antidiabetic medicines. Individuals should monitor their blood sugar, as acebutolol can also mask the signs of hypoglycaemia. Hydrochlorothiazide may increase blood sugar.
When taken together with cisapride, sertindole, sotalol, astemizole, terfenadine or beta-agonist bronchodilators such as salbutamol, there may be an increased risk of abnormal heart rhythm, if low blood potassium (hypokalaemia) occurs with hydrochlorothiazide. If hypokalaemia does not occur, this risk is removed.
When taken together with other medicines which can cause hypokalaemia e.g. corticosteroids, carbenoxolone or beta-agonist bronchodilators such as salbutamol, there may be an increased risk of developing hypokalaemia. Potassium supplements may be required.
When taken together with cardiac glycosides such as digoxin, there is an increased risk of adverse effects if low blood potassium (hypokalaemia) occurs with hydrochlorothiazide. There is also an increased risk of extremely slow heart rate when acebutolol is taken with digoxin.
Hydrochlorothiazide reduces the ability of the body to remove the medicine lithium. As this can give rise to adverse effects, this medicine should not generally be taken with lithium.
When acebutolol is taken together with calcium channel blockers such as verapamil, the risk of slow heart rate, hypotension and heart failure may be increased. This medication should not be taken together with verapamil or within several days of verapamil therapy and vice versa.
Tricyclic and Mono Amine Oxidase Inhibitor (MAOI) antidepressants should not be used with this medicine.