An angiotensin-receptor blocker (ARB)
Telmisartan
A long-acting once-daily ARB for high blood pressure; it does not cause the ACE-inhibitor cough but must be avoided in pregnancy.
What is Telmisartan?
Telmisartan is a long-acting angiotensin-receptor blocker (ARB). It lowers blood pressure and is also used to help protect the heart and blood vessels in people at higher cardiovascular risk.
Education and reference only. This is a plain-language guide to Telmisartan — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Telmisartan is a long-acting angiotensin-receptor blocker (ARB). It lowers blood pressure and is also used to help protect the heart and blood vessels in people at high cardiovascular risk. Like other ARBs it works on the same hormone system as ACE inhibitors but rarely causes the dry cough they can produce, so it is a common choice when an ACE inhibitor is not tolerated. Its long duration of action makes it a convenient once-daily tablet that keeps blood pressure controlled smoothly over the whole day, including the early morning. In the UK and US the active ingredient and the original brand (Micardis) are the same; generic telmisartan is identical.
How it works
Telmisartan blocks the receptor that angiotensin II acts on, rather than blocking the enzyme that makes it. Angiotensin II is a hormone that tightens blood vessels and makes the body hold on to salt and water; by stopping it from reaching its receptor, telmisartan lets blood vessels relax and reduces fluid load, so blood pressure falls and the heart has less to work against. Because it acts one step further along than an ACE inhibitor, it does not build up the airway chemicals that cause the ACE-inhibitor cough. Telmisartan is one of the longest-acting ARBs, which is why a single daily dose covers a full day.
Company & origin
Originated / developed by: Boehringer Ingelheim.
Telmisartan, an angiotensin II receptor blocker, was discovered and developed by Boehringer Ingelheim (Germany) and received US FDA approval in November 1998, marketed as Micardis.
What it treats
Conditions Telmisartan is used for
Practical use
How to take Telmisartan
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take telmisartan once daily at around the same time, with or without food.
- Stand up slowly when you start treatment, as your blood pressure may dip and cause light-headedness.
- Your prescriber will usually check your kidney function and blood potassium with blood tests during treatment.
- Avoid potassium supplements or salt substitutes unless your prescriber agrees, as ARBs can raise potassium.
- Tell your prescriber if you might be pregnant, as ARBs are not suitable in pregnancy.
Weighing it up
Advantages & disadvantages of Telmisartan
Advantages
- Effective once-daily medicine for high blood pressure with a long duration of action.
- Often well tolerated and, unlike ACE inhibitors, much less likely to cause a dry cough.
- Has a role in protecting the heart and blood vessels in higher-risk people.
- Combines well with other blood-pressure treatments.
Disadvantages
- Can cause dizziness, especially when first started.
- May raise blood potassium and affect kidney function, so blood tests are needed.
- Must not be used in pregnancy.
- Not usually combined with an ACE inhibitor because of added risks.
Practical use
Good to know
It is taken once a day at a consistent time, often started low and built up, with a blood-pressure and blood-test check after starting and after increases. Its long action gives smooth, steady control across the day. Like other ARBs it can raise blood potassium and affect kidney function in some people, so blood tests are checked. It must be stopped in pregnancy — medicines acting on this hormone system can harm the developing baby — so anyone planning a pregnancy or who becomes pregnant should be switched promptly. Anti-inflammatory painkillers (NSAIDs), especially alongside a water tablet, can stress the kidneys.
Who should not take it / use with caution
- Women who are pregnant or planning pregnancy — ARBs are contraindicated in pregnancy and switched beforehand, as they can harm the developing baby.
- Used with caution in significant kidney artery narrowing, low blood pressure, a high blood potassium level, or significant liver impairment.
- It is not normally combined with an ACE inhibitor, as together they raise the risk of kidney problems and high potassium.
Monitoring
- Blood pressure
- Kidney function and blood potassium before and after starting/increasing
- Tolerability
Side effects
- Dizziness or light-headedness, especially on standing or when starting.
- A rise in blood potassium or a change in kidney function (watched with blood tests).
- Generally well tolerated; unlike ACE inhibitors it rarely causes a dry cough, and angioedema (sudden swelling of the face or throat) is very rare.
Key interactions
- NSAID painkillers (e.g. ibuprofen) can reduce its effect and stress the kidneys, especially alongside a diuretic.
- Potassium supplements, potassium-based salt substitutes and certain diuretics can push potassium too high.
- Care with other blood-pressure-lowering medicines, with ACE inhibitors, with lithium, and with some diabetes medicines.
Available as: Tablets (several strengths), and combination tablets with a water tablet (diuretic) or a calcium-channel blocker.
Answers
Telmisartan: frequently asked questions
Why was I switched from an ACE inhibitor to telmisartan?
The most common reason is a persistent dry cough from the ACE inhibitor. Telmisartan controls blood pressure in much the same way but rarely causes that cough, so it is a well-matched alternative. Its long action also gives smooth control across the whole day.
Can I take telmisartan if I might become pregnant?
No — ARBs including telmisartan must be avoided in pregnancy because they can harm the developing baby, particularly later on. If you are planning a pregnancy, or think you may be pregnant, tell your prescriber promptly so you can be switched to a medicine that is safe in pregnancy.
Why does it rarely cause a cough when ACE inhibitors do?
ACE inhibitors cause cough by raising certain airway chemicals. Telmisartan acts one step further along the same hormone system — blocking angiotensin II at its receptor — so it does not build up those chemicals, and a dry cough is much less likely.
Can I take ibuprofen with telmisartan?
Occasional use may be fine, but regular anti-inflammatory painkillers (NSAIDs) can reduce telmisartan's effect and, especially alongside a water tablet, can harm the kidneys. Check with your pharmacist and prefer paracetamol where suitable.
What is the difference between telmisartan and Micardis?
They are the same medicine — telmisartan is the generic (active-ingredient) name and Micardis is the original brand name, used in both the UK and US. Generic telmisartan contains the identical active ingredient.
The wider class
About ARBs
Telmisartan belongs to the arbs class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
Browse by body system
Authoritative sources
- BNF: Telmisartan.
- electronic Medicines Compendium (SmPC): Telmisartan (Micardis).
- NICE CKS: Telmisartan.
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