Health Centres - CoAprovel
How does it work?
CoAprovel tablets contain two active ingredients, irbesartan and hydrochlorothiazide.
Hydrochlorothiazide is a type of medicine known as a thiazide diuretic. Thiazide diuretics act in the kidneys, where they increase the production of urine. They work by causing the kidneys to increase the amount of salts, such as potassium and sodium, that are filtered out of the blood and into the urine. When these salts are filtered out of the blood by the kidneys, water is also drawn alongside. As hydrochlorothiazide increases the removal of salts from the blood, it also causes more water to be drawn out of the blood and into the urine.
Removing water from the blood decreases the volume of fluid circulating through the blood vessels, which decreases the pressure within the blood vessels. Hydrochlorothiazide therefore lowers blood pressure.
Irbesartan is a type of medicine called an angiotensin II receptor antagonist. It works by preventing the action of a hormone in the body called angiotensin II.
Angiotensin II normally acts on special receptors in the body, with two main results. Firstly, it causes the peripheral blood vessels to narrow, and secondly, it stimulates the production of another hormone called aldosterone. Aldosterone causes salt and water to be retained by the kidneys, which increases the volume of fluid in the blood vessels.
Irbesartan blocks the receptors that angiotensin II acts on, and so prevents its actions. The main result of this is that the peripheral blood vessels are allowed to widen, which means that there is more space and less resistance in these blood vessels. This lowers the pressure inside the blood vessels.
Blocking the actions of angiotensin II also reduces the action of aldosterone on the kidneys. The result of this is an increase in the amount of fluid removed from the blood by the kidneys. This decreases the amount of fluid in the blood vessels, which also lessens the resistance and pressure in the blood vessels.
Irbesartan and hydrochlorothiazide have an additive effect on lowering blood pressure. They are used to treat high blood pressure in people whose blood pressure is not adequately controlled on one of the medicines alone.
What is it used for?
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High blood pressure with no known cause.
Warning!
- Dizziness and weariness may occasionally occur during treatment with blood pressure lowering medicines. If you are affected, caution is required when driving or operating machinery.
- This medicine may sometimes cause your blood pressure to drop when you move from a lying down or sitting position to sitting or standing, especially when you first start taking the medicine. This may make you feel dizzy or unsteady. To avoid this try getting up slowly. If you do feel dizzy, sit or lie down until the symptoms pass.
- It is recommended that the levels of salts (electrolytes such as potassium and sodium) in your blood should be monitored while you are taking this medicine. If you experience any of the following symptoms 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.
- If you need a test to assess the functioning of your parathyroid gland your doctor may ask you to stop taking this medicine beforehand, as it may interfere with the test results.
- People with decreased kidney function should have their potassium blood level and kidney function monitored while taking this medicine.
- People with high blood pressure caused by high levels of the hormone aldosterone (primary hyperaldosteronism) do not generally respond to this type of blood pressure lowering medicine, and it is not recommended for these people.
- There is no information regarding the use of this medicine in children and adolescents under the age of 18 years.
Use with caution in
- Decreased kidney function
- Narrowing of the artery which supplies blood to the kidneys (renal artery stenosis)
- Decreased liver function
- Liver disease
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Heart disease caused by inadequate blood flow to the heart
- Heart disease characterised by thickening of the internal heart muscle and a blockage inside the heart (hypertrophic obstructive cardiomyopathy)
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Heart failure
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Narrowing of one of the valves in the heart
- Narrowing of the main artery of the body (aortic stenosis)
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Diabetes
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Gout
- History of allergies
- History of asthma
- Long-term inflammation of skin and some internal organs (systemic lupus erythematosus)
- People with low fluid volume or salt levels in the body, eg due to diuretic therapy, low-sodium diet, diarrhoea or vomiting.
Not to be used in
- Allergy to medicines from the sulphonamide group, eg the antibiotic sulfamethoxazole
- Moderate to severely decreased kidney function
- Severely decreased liver function
- Liver damage due to disorder of the bile duct (biliary cirrhosis)
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Failure of the normal flow of bile from the liver to the intestines
- High levels of calcium in the blood (hypercalcaemia)
- Low potassium blood levels that cannot be corrected (refractory hypokalaemia)
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Pregnancy
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Breastfeeding
- Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (CoAprovel tablets contain lactose).
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.
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, particularly in the second and third trimesters, as it may affect the growth and development of the foetus or have adverse effects on foetal tissues. Seek medical advice from your doctor.
- This medicine may pass into breast milk and may also reduce the production of breast milk. It should not be used by breastfeeding mothers. Seek medical advice from your doctor.
Side effects
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.
- Dizziness
- Fatigue
- Nausea and vomiting
- Headache
- Diarrhoea
- A drop in blood pressure that occurs when going from lying down to sitting or standing, which results in dizziness and lightheadedness (postural hypotension)
- Fainting
- Increased heart rate (tachycardia)
- High blood glucose level (hyperglycaemia)
- Flushing
- Weakness or loss of strength (asthenia)
- Disturbances in the levels of chemical components (electrolytes) in the blood
- Sexual problems
- Sensation of ringing, or other noise in the ears (tinnitus)
- Pain in the muscles and joints
- Liver or kidney disorders
- Blood disorders
- Severe swelling of lips, face or tongue (angioedema)
The side effects listed above may not include all of the side effects reported by the drug's manufacturer.
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