What is it used for?
How does it work?
MicardisPlus tablets contain two active ingredients, telmisartan 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.
Telmisartan 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.
Telmisartan 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.
Telmisartan 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.
- Blood pressure medicines such as this one may occasionally cause drowsiness 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.
- You should take extra care if you drink alcohol while taking this medicine, as it may enhance the blood pressure lowering effect and could make you feel dizzy or faint.
- 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.
- It is recommended that the levels of salts (electrolytes) in your blood should be monitored while taking this medicine.
- 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: dry mouth, thirst, feeling weak or lethargic, drowsiness, restlessness, muscle cramps, scanty production of urine, racing heartbeat, nausea or vomiting.
- If you have any existing problems with your kidney function you should have regular blood tests to monitor your kidney function and the level of potassium in your blood while taking this medicine.
- 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.
- This medicine may be less effective at lowering blood pressure in people of Afro-Caribbean descent.
Use with caution in
- People with a low volume of fluid or salt in their body, eg due to diuretic therapy, low salt diet, kidney dialysis, diarrhoea, vomiting, dehydration.
- Mild to moderately decreased liver function or liver disease.
- Decreased kidney function or kidney disease.
- People with narrowing in the one or both of the arteries that supply blood to the kidneys (renal artery stenosis).
- People with narrowing of the main artery that leaves the heart to supply blood to the body (aortic stenosis).
- Heart valve disease (mitral valve stenosis).
- Heart disease characterised by thickening of the internal heart muscle and a blockage inside the heart (hypertrophic obstructive cardiomyopathy).
- Severe heart failure.
- Heart disease caused by inadequate blood flow to the heart (ischaemic heart disease, eg angina).
- History of allergies.
- History of asthma.
- A disease called systemic lupus erythematosus in which there is long-term inflammation of skin and some internal organs.
Not to be used in
- Allergy to medicines from the sulphonamide group, eg the antibiotic sulfamethoxazole.
- Severely decreased kidney function.
- Severely decreased liver function.
- Blockage of the bile duct (biliary obstruction).
- Failure of the normal flow of bile from the liver to the intestines (cholestasis).
- People with a low level of potassium in the blood that cannot be corrected (refractory hypokalaemia).
- People with a high level of calcium in the blood (hypercalcaemia).
- MicardisPlus tablets contain sorbitol and are not suitable for people with an inherited intolerance to fructose in the diet.
- MicardisPlus tablets contain lactose and are not suitable for people with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption.
- The safety of this medicine has not been established in children and adolescents under the age of 18. It is not recommended for this age group.
- People with high blood pressure due to 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.
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 during pregnancy, particularly the second and third trimesters, as it may be harmful to the developing baby. If you get pregnant during treatment or want to try for a baby, you should stop taking this medicine and consult your doctor. If appropriate, your doctor may prescribe you a different blood pressure medicine that is safe to take during pregnancy. Seek further medical advice from your doctor.
- It is not known if telmisartan passes into breast milk. Hydrochlorothiazide does pass into breast milk, and it may also decrease the quantity of breast milk produced. For this reason, the manufacturer states that this medicine should not be used during breastfeeding. Seek medical advice from your doctor.
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. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.
Common (affect between 1 in 10 and 1 in 100 people)
Uncommon (affect between 1 in 100 and 1 in 1000 people)
- Dry mouth.
- Wind (flatulence).
- Decreased level of potassium in the blood (hypokalaemia).
- Sensation of spinning (vertigo).
- Low blood pressure (hypotension).
- Drop in blood pressure that causes dizziness when moving from a lying down or sitting position to sitting or standing.
- Pins and needles sensations.
- Increased heart rate (tachycardia).
- Abnormal heart beats (arrhythmias).
- Shortness of breath.
- Pain in the muscles or back.
- Chest pain.
- Erectile dysfunction (impotence).
- Increased level of uric acid in the blood.
- Decreased kidney function, including kidney failure.
Rare (affect between 1 in 1000 and 1 in 10,000 people)
- Abdominal pain.
- Indigestion (dyspepsia).
- Decreased level of sodium in the blood (hyponatraemia).
- Difficulty sleeping (insomnia).
- Visual disturbances such as blurred vision.
- Increased sweating.
- Skin reactions such as redness, rash, hives or itching.
- Muscle cramps.
- Joint pain.
- Flu-like symptoms.
- Liver problems.
- Severe swelling of lips, face, tongue or throat (angioedema). Stop taking this medicine and consult your doctor immediately if you experience difficulty breathing or swallowing, or swelling of your face, lips, tongue or throat while taking this medicine.
The side effects listed above may not include all of the side effects reported by the medicine'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?
It is important to tell your doctor or pharmacist what medicines you are taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Likewise, always check with your doctor or pharmacist before taking any other medicines during treatment with this one so that they can make sure that the combination is safe.
This medicine will have an additive effect with other medicines that decrease blood pressure, particularly other medicines used to treat high blood pressure (antihypertensives). This may cause dizziness, particularly when standing up. This can usually be relieved by lying down until the symptoms pass. If you frequently feel dizzy while taking this medicine in combination with other medicines that can lower blood pressure you should let your doctor know, as your doses may need adjusting. Other medicines that decrease blood pressure include the following:
- ACE inhibitors, eg captopril
- alpha-blockers such as prazosin
- other angiotensin II receptor antagonists such as losartan
- benzodiazepines, eg temazepam, diazepam
- beta-blockers such as propranolol
- calcium-channel blockers such as verapamil, nifedipine
- diuretics, eg furosemide, bendroflumethiazide
- dopamine agonists, eg bromocriptine, apomorphine
- MAOI antidepressants, eg phenelzine
- nitrates, eg glyceryl trinitrate
Non-steroidal anti-inflammatory drugs (NSAIDs, eg indometacin, aspirin, diclofenac, ibuprofen) may reduce the blood pressure lowering effect of this medicine, and may increase the risk of a decline in kidney function. You should avoid taking this type of painkiller unless recommended by your doctor.
Hydrochlorothiazide can decrease the amount of potassium in the blood. If this medicine is taken with other medicines that can lower blood potassium, this effect may be enhanced. The amount of potassium in your blood should be monitored if you are taking any of these medicines:
- beta agonist bronchodilators, eg salbutamol
- corticosteroids, eg prednisolone
- other diuretics, eg furosemide, bendroflumethiazide
Telmisartan may increase the amount of potassium in the blood. If this medicine is taken with other medicines that can increase blood potassium, this effect may be enhanced. If you are taking any of these with this medicine you should have regular blood tests to monitor the amount of potassium in your blood:
- ACE inhibitors, eg enalapril, captopril
- other angiotensin II receptor antagonists, eg losartan
- epoetin (this may also oppose the blood pressure lowering effect of telmisartan)
- NSAIDs, eg indometacin, aspirin, diclofenac, ibuprofen
- potassium-containing salt substitutes (eg Lo-Salt)
- potassium salts, eg potassium citrate for cystitis
- potassium-sparing diuretics, eg spironolactone, triamterene, amiloride
- potassium supplements
If the amount of potassium in your blood drops too low and you are also taking any of the following medicines, there may be an increased risk of abnormal heart beats:
- the antihistamines astemizole or terfenadine
- certain antimalarials, eg halofantrine, chloroquine, quinine
- certain antipsychotics, eg thioridazine, chlorpromazine, sertindole, haloperidol
- intravenous erythromycin or pentamidine
- medicines for abnormal heartbeats (antiarrhythmics), eg amiodarone, procainamide, disopyramide, sotalol.
Hydrochlorothiazide can increase blood calcium levels. If you take calcium or vitamin D supplements regularly with this medicine, the level of calcium in your blood should be monitored.
Both telmisartan and hydrochlorothiazide may increase the blood level of the medicine lithium, and this medicine is therefore not recommended for people taking lithium. If it is necessary to take this medicine with lithium, your doctor should carefully monitor your blood level of lithium.
Telmisartan may also increase the blood level of the medicine digoxin. If you are taking digoxin in combination with this medicine, your doctor may need to monitor your digoxin level to make sure it doesn't rise too high.
Hydrochlorothiazide may increase blood glucose levels. If you have diabetes you should carefully monitor your blood sugar while taking this medicine, as the dose of your antidiabetic medicine may need adjusting. The effect on your blood sugar may be enhanced if you are also taking diazoxide or a beta-blocker medicine. Discuss this with your doctor.
This medicine should not be taken within four hours of colestipol or cholestyramine, as these medicines may reduce the absorption of hydrochlorothiazide from the gut.
Other medicines containing the same active ingredients
There are currently no other medicines available in the UK that contain both telmisartan and hydrochlorothiazide as the active ingredients.
Micardis contains telmisartan on its own.