Amlodipine, valsartan (Exforge)
How does it work?
Exforge tablets contain two active ingredients, amlodipine and valsartan. Valsartan is a type of medicine called an angiotensin II receptor antagonist. Amlodipine is a type of medicine called a calcium-channel blocker. These are both medicines used to lower high blood pressure.
Valsartan 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. It causes the peripheral blood vessels to narrow, and it also 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.
Valsartan 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 helps lower blood pressure.
Amlodipine works by slowing the movement of calcium through the muscle cells that are found in the walls of blood vessels and heart. It does this by blocking 'calcium channels' in these muscle cells. Calcium is needed by muscle cells in order for them to contract, so by depriving them of calcium, amlodipine causes the muscle cells to relax. Amlodipine acts specifically on the muscle cells in the walls of arteries, causing them to relax. This allows the arteries in the body to widen.
The relaxing and widening of the small arteries in the body decreases the resistance that the heart has to push against in order to pump the blood around the body. This reduces the pressure within the blood vessels. Amlodipine can therefore be used to treat high blood pressure.
What is it used for?
- High blood pressure with no known cause (essential hypertension).
This combination of valsartan and amlodipine is used when blood pressure has not been lowered sufficiently by taking valsartan or amlodipine alone.
How do I take it?
- One Exforge tablet should be taken once a day, preferably at the same time each day.
- The tablets should be swallowed with a drink of water. They can be taken either with or without food.
- If you forget to take a dose don't worry, just leave out that dose and take your next dose as usual. Don't take a double dose to make up for a missed dose.
- Dizziness and weariness may occasionally occur during treatment with blood pressure lowering medicines. Dizziness can be relieved by lying down until the symptoms pass. You should take extra care performing potentially hazardous tasks such as driving or operating machinery until you know how this medicine affects you and you are sure you can perform these activities safely.
- Your blood pressure should be regularly monitored while you are taking this medicine.
- If you have any problems with your kidneys your kidney function and the amount of potassium in your blood should be regularly monitored while you are 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.
Use with caution in
- People over 65 years of age.
- Moderately decreased kidney function.
- People with narrowing of the arteries that supply blood to the kidneys (renal artery stenosis).
- People who have had a kidney transplant.
- Mild to moderately decreased liver function.
- People with a blockage of the bile ducts (biliary obstruction, eg due to gallstones).
- Heart failure.
- 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).
- People with low fluid volume or salt levels in the body, eg due to diuretic therapy, low-sodium diet, diarrhoea or vomiting.
- Hereditary blood disorders called porphyrias.
- People who have previously experienced an allergic reaction to a medicine that involved swelling of the lips, face, throat or tongue (angioedema).
Not to be used in
- People allergic to related calcium-channel blockers (dihydropyridines, eg nifedipine).
- People with very low blood pressure (hypotension).
- People with severely decreased liver function.
- People with a rare form of liver disease involving the bile ducts (biliary cirrhosis).
- People with failure of the normal flow of bile from the liver to the intestines (cholestasis).
- People with severely decreased kidney function or who are having kidney dialysis.
- A condition where the heart fails to maintain adequate circulation of blood (cardiogenic shock).
- People with significant narrowing of the main artery that leaves the heart to supply blood to the body (aortic stenosis).
- Heart disease characterised by thickening of the internal heart muscle and a blockage inside the heart (hypertrophic obstructive cardiomyopathy).
- People with unstable heart failure following a heart attack.
- Children or adolescents under the age of 18 years.
This medicine should not be used if you are allergic to 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, particularly in the second and third trimesters, as it may be harmful to the unborn baby. Seek further medical advice from your doctor. If you get pregnant while taking this medicine, stop taking it and consult your doctor immediately.
- It is not known if valsartan and/or amlodipine pass into breast milk. This medicine should therefore not be used during breastfeeding. Mothers will need to either stop breastfeeding while taking this medicine, or not take this medicine. This will depend on how important the medicine is for treating the mother’s blood pressure. It is important to 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, it 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)
- Excessive fluid retention in the body tissues, resulting in swelling (oedema).
- Swelling of feet or ankles (peripheral oedema).
- Weakness or loss of strength (asthenia).
- Hot flushes.
- Cold and flu like symptoms.
- Inflammation of the nose and throat, causing a blocked or runny nose and sore throat (nasopharyngitis).
- Decreased level of potassium in the blood (hypokalaemia).
Uncommon (affect between 1 in 100 and 1 in 1000 people)
- Pins and needles (paraesthesia).
- A drop in blood pressure that occurs when going from lying down to sitting or standing, which results in dizziness and lightheadedness (postural hypotension).
- Sensation of spinning (vertigo).
- Increased heart rate (tachycardia).
- Awareness of your heartbeat (palpitations).
- Pain in the muscles, joints or back.
- Skin reactions such as redness, rash.
- Disturbances of the gut such as nausea, vomiting, indigestion, diarrhoea, constipation, abdominal pain.
- Dry mouth.
- Loss of appetite.
- Raised level of calcium or uric acid in the blood (hypercalcaemia or hyperuricaemia).
- Raised levels of fats in the blood (hyperlipidaemia).
Rare (affect between 1 in 1000 and 1 in 10,000 people)
- Increased urinary frequency.
- Erectile dysfunction.
- Sensation of ringing, or other noise in the ears (tinnitus).
- Visual disturbances.
- Sensation of heaviness.
- Excessive sweating.
- Muscle spasms.
- Low blood pressure.
- Itchy skin.
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 already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.
This medicine is likely to have an additive effect with other medicines that decrease blood pressure, particularly medicines that are used to treat high blood pressure (antihypertensives). This may cause dizziness, which can usually be relieved by lying down until the symptoms pass. If you 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 enalapril
- alpha-blockers such as prazosin
- other angiotensin II receptor antagonists such as losartan
- antipsychotics such as chlorpromazine
- benzodiazepines, eg temazepam, diazepam
- beta-blockers such as propranolol
- other calcium-channel blockers such as verapamil, nifedipine
- diuretics, eg furosemide, bendroflumethiazide
- dopamine agonists, eg bromocriptine, apomorphine
- MAOI antidepressants, eg phenelzine
- nitrates, eg glyceryl trinitrate
Valsartan may increase the level of potassium in your blood. If this medicine is taken with other medicines that can increase blood potassium levels, this effect may be enhanced. Such medicines include those listed below. If any of these are used in combination with Exforge, the amount of potassium in your blood should be monitored:
- non-steroidal anti-inflammatory drugs, eg indometacin, diclofenac, ibuprofen
- potassium-sparing diuretics (eg spironolactone, triamterene, amiloride)
- potassium salts, eg potassium citrate for cystitis
- potassium supplements
- potassium-containing salt substitutes such as Lo-Salt
Valsartan may increase blood levels of the medicine lithium, and this medicine is therefore not recommended for people taking lithium. If it is necessary to take both, your doctor should carefully monitor your blood levels of lithium and you should let your doctor know if you experience any signs that your lithium level is increasing, for example, loss of appetite, diarrhoea, vomiting, blurred vision, muscle weakness, lack of co-ordination, drowsiness, tremor, unsteadiness, muscle twitching, ringing in the ears or confusion.
Amlodipine increases the blood level of the cholesterol-lowering medicine simvastatin and this could increase the chance of simvastatin having side effects on your muscles. Your dose of simvastatin should not be higher than 20mg daily if you are also taking Exforge.
The following medicines may increase the amount of amlodipine in your blood and this could increase the risk of its side effects:
- protease inhibitors for HIV infection, eg ritonavir, nelfinavir, saquinavir
If you take any of these with Exforge, you should tell your doctor if you feel dizzy or experience any other side effects, as the dose of your Exforge may need to be reduced.
The following medicines may decrease the amount of amlodipine in your blood and so could make it less effective. As a result, your doctor may need to prescribe you a higher dose of Exforge tablets if you are taking any of these:
- the herbal remedy St. John's wort (Hypericum perforatum).
The following medicines may oppose the blood pressure lowering effect of this medicine:
- corticosteroids, such as dexamethasone or prednisolone
- oestrogens, such as those in the contraceptive pill
- regular use of non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, diclofenac or indomethacin (occasional painkilling doses are unlikely to have a significant effect).
Other medicines containing the same active ingredient
There are currently no other medicines available in the UK that contain both valsartan and amlodipine.
Diovan contains just valsartan.
Istin contains just amlodipine. Amlodipine tablets are also available as the generic medicine, ie without a brand name.