Telmisartan

Angiotensin receptor blockers are widely used in cardiovascular therapy for their effective blood pressure management and tolerability profile, particularly in patients who cannot take ACE inhibitors. Telmisartan tablets are a prescription-only ARB used in adults for the treatment of essential hypertension and, in eligible patients aged 55 and over, for the reduction of cardiovascular risk. Telmisartan acts on the renin-angiotensin system by blocking the AT1 receptor and has one of the longest durations of action among ARBs currently available in the UK. A prescription can only be issued following a clinical consultation.

Telmisartan tablets are an oral prescription medicine containing telmisartan as the active ingredient. Telmisartan belongs to the angiotensin receptor blocker (ARB) class of medicines, also known as angiotensin II receptor antagonists. ARBs are commonly prescribed as antihypertensive agents and are recommended in NICE guideline NG136 for the treatment of hypertension in adults, particularly those who cannot tolerate ACE inhibitors due to a persistent cough.

Telmisartan is licensed in the UK for two indications. The first is treatment of essential hypertension in adults. The second is reduction of cardiovascular events (heart attack and stroke) in adults aged 55 and over who have established atherosclerotic cardiovascular disease (such as a history of coronary artery disease, stroke, or peripheral artery disease) or type 2 diabetes with documented target organ damage. This second indication is based on evidence from the ONTARGET clinical trial.

Generic telmisartan tablets are available from multiple manufacturers. Telmisartan has a particularly long half-life compared to many other ARBs. This supports effective blood pressure control over a full 24-hour period from a single daily dose and is one of the reasons it is used in the cardiovascular risk reduction setting where consistent RAAS support throughout the day and night is important.

Telmisartan lowers blood pressure and provides cardiovascular protection through its selective blockade of the AT1 receptor in the renin-angiotensin system.

AT1 Receptor Blockade

Angiotensin II is a hormone produced through the renin-angiotensin system that raises blood pressure by causing blood vessels to narrow and promoting sodium and water retention. Angiotensin II exerts these effects by binding to the AT1 receptor. Telmisartan selectively and competitively blocks the AT1 receptor. By preventing angiotensin II from binding, telmisartan stops these blood pressure raising effects. Blood vessels remain relaxed, fluid balance is improved, and blood pressure falls.

Long Duration of Action

Telmisartan has a plasma half-life of approximately 24 hours, which is longer than most other ARBs. This extended duration of action means it continues to provide AT1 blockade and blood pressure control throughout the full 24-hour dosing interval, including the early morning hours when blood pressure naturally rises and cardiovascular risk is highest. This pharmacokinetic profile underpins both its use in hypertension and its role in reducing cardiovascular events in high-risk patients.

Unlike ACE inhibitors, telmisartan does not affect the breakdown of bradykinin. This means it does not typically cause the dry persistent cough associated with ACE inhibitors, making it a well-tolerated alternative for patients in whom ACE inhibitor cough is a problem.

Always take telmisartan exactly as your prescriber instructs. The information below summarises key points from the current UK SmPC. Read the Patient Information Leaflet supplied with your medicine before starting treatment.

• Take one tablet once daily, at approximately the same time each day.
• Telmisartan can be taken with or without food.
• Swallow the tablet whole with a glass of water.
• If you miss a dose, take it as soon as you remember on the same day. If you only remember the following day, skip the missed dose and continue as normal. Do not take two doses on the same day.
• Do not stop taking telmisartan without speaking to your prescriber first. High blood pressure and cardiovascular risk both require ongoing management.
• Your prescriber will typically review your blood pressure response after four weeks and may adjust the dose if needed. Kidney function and potassium levels may be checked periodically.
• Attend all follow up appointments so your treatment can be safely assessed and optimised.
• If you are taking telmisartan for cardiovascular risk reduction rather than hypertension, keep your specialist or GP informed of your ongoing cardiovascular care.

Telmisartan tablets are available in three strengths. The appropriate dose is determined by your prescriber based on the indication being treated and your individual blood pressure response.

Telmisartan 20 mg Tablets

The 20 mg tablet is a lower strength option used when a cautious starting dose is appropriate, such as in patients with liver impairment or in those who may be sensitive to the initial blood pressure lowering effect. The current UK SmPC notes that the 20 mg dose provides a modest antihypertensive effect and is not the standard starting dose for most adults. It may be used during dose initiation in specific clinical circumstances at the prescriber's discretion.

Telmisartan 40 mg Tablets

The 40 mg tablet is the standard recommended starting dose for essential hypertension. Most patients will achieve adequate blood pressure control at 40 mg once daily. Blood pressure is typically reviewed after four weeks to assess response. For the cardiovascular risk reduction indication, 80 mg once daily is the target dose, so the 40 mg tablet may be used during initial titration toward this target.

Telmisartan 80 mg Tablets

The 80 mg tablet is the maximum recommended dose and is used in two contexts. For hypertension, it is prescribed in patients whose blood pressure is not adequately controlled at 40 mg after four weeks. For cardiovascular risk reduction in adults aged 55 and over, 80 mg is the target dose used in the ONTARGET trial, and the SmPC recommends this dose for this indication. All dose adjustments are made by your prescriber. Do not change your dose without medical advice.

Like all medicines, telmisartan can cause side effects, although not everyone experiences them. The information below is based on the current UK SmPC. Refer to the Patient Information Leaflet for the full list.

Common Side Effects (may affect up to 1 in 10 people)

• Dizziness, particularly on standing up quickly.
• Raised blood potassium (hyperkalaemia). Your prescriber may arrange blood tests to monitor this during treatment.
• Low blood pressure (hypotension), particularly in patients who are volume depleted or also taking diuretics.

Uncommon Side Effects (may affect up to 1 in 100 people)

• Headache.
• Fatigue.
• Nausea or abdominal discomfort.
• Changes in kidney function, particularly in patients with pre existing kidney disease.
• Skin rash or itching.

Serious Side Effects: Seek Urgent Medical Attention

Go to your nearest accident and emergency department or call 999 immediately if you experience:

• Angioedema: sudden swelling of the face, lips, tongue, or throat. This is rare but potentially life threatening. Seek emergency help immediately. If you have had angioedema from any ARB or ACE inhibitor, you must tell your prescriber before starting telmisartan.
• Signs of severely raised potassium such as muscle weakness, irregular heartbeat, or confusion.
• A significant reduction in urine output, which may indicate a kidney problem.

Report any suspected side effect to your prescriber, pharmacist, or via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

Telmisartan Tablets May Be Suitable If You:

• Are an adult with a confirmed diagnosis of essential hypertension.
• Cannot tolerate ACE inhibitors due to a persistent dry cough and require an ARB as an alternative antihypertensive.
• Are aged 55 or over with established atherosclerotic cardiovascular disease or type 2 diabetes with target organ damage, and your prescriber has determined that telmisartan is appropriate for cardiovascular risk reduction.
• Are already prescribed telmisartan and require a repeat prescription through an online prescribing service.

Telmisartan Tablets Are Not Suitable If You:

• Are pregnant or planning to become pregnant. Telmisartan is contraindicated in pregnancy. ARBs cause serious harm to the developing baby, particularly in the second and third trimesters, including kidney damage, skull abnormalities, and foetal death. Contact your prescriber immediately if you become pregnant while taking telmisartan.
• Are breastfeeding.
• Have severe liver disease or biliary obstruction.
• Have severe kidney impairment or are on dialysis.
• Have diabetes or moderate to severe kidney impairment and are also taking aliskiren.
• Have a known allergy or hypersensitivity to telmisartan or any excipient listed in the SmPC.
• Are under 18 years of age.

Tell your prescriber about all medicines you take. The following interactions are of particular clinical importance for telmisartan:

• Potassium supplements, potassium-sparing diuretics (such as spironolactone or amiloride), and potassium-containing salt substitutes: these can raise blood potassium to dangerous levels when combined with telmisartan.
• NSAIDs such as ibuprofen: regular use can reduce the blood pressure lowering effect of telmisartan and increase the risk of kidney problems.
• Lithium: telmisartan can increase lithium blood levels. Close monitoring is required.
• Aliskiren: contraindicated in combination with telmisartan in patients with diabetes or significant kidney impairment.
• Digoxin: telmisartan can increase digoxin blood levels. Monitoring of digoxin levels may be required.
• Ramipril: the ONTARGET trial demonstrated that the combination of telmisartan and ramipril provides no additional cardiovascular benefit compared to either medicine alone, but significantly increases adverse effects including kidney problems and hypotension. This combination is not recommended.

Your prescriber will review all current medicines during the clinical assessment before any prescription is considered.

Telmisartan is a Prescription Only Medicine. The clinical consultation is the essential first step. A prescription will only be issued if a registered prescriber concludes, based on their individual assessment of your circumstances, that telmisartan is clinically appropriate for you.

During your online consultation with Pharmacy Planet, a registered prescriber will review the information you provide. This includes your diagnosis, blood pressure history, cardiovascular history, kidney function where available, current medicines, and other relevant medical information. The prescriber will assess which strength is appropriate and which indication applies, and whether online prescribing is suitable for your individual situation.

If you are under the care of your GP or a specialist for hypertension, cardiovascular disease, or diabetes, please keep them informed of all medicines prescribed through online services. Coordinated care supports the safest approach to blood pressure management and cardiovascular therapy.

Store below 30°C. Store in the original packaging to protect from moisture. Keep out of the sight and reach of children. Do not use after the expiry date printed on the packaging. Do not dispose of medicines via household waste or wastewater. Return unused or out of date tablets to your pharmacist for safe disposal. Full storage instructions are provided in the Patient Information Leaflet supplied with your medicine.

Pharmacy Planet is a GPhC-registered online pharmacy providing access to prescription medicines through a clinically led consultation process. Our registered prescribers and pharmacists are committed to patient safety, clinical accuracy, and responsible prescribing. We follow GPhC standards, MHRA guidance, and ASA advertising regulations in all aspects of our service. Every prescription is reviewed and dispensed by qualified healthcare professionals. We provide clear, factual information to help patients understand their antihypertensive medication and make informed decisions about their blood pressure management and cardiovascular therapy. If you have questions about telmisartan or any other medicine, our pharmacy team is available to help. We are committed to transparent, patient centred care.

References

1. Electronic Medicines Compendium (eMC). Telmisartan 20 mg, 40 mg and 80 mg tablets — Summary of Product Characteristics. https://www.medicines.org.uk/emc. Accessed May 2026.
2. National Institute for Health and Care Excellence (NICE). Hypertension in adults: diagnosis and management. NICE guideline NG136. https://www.nice.org.uk/guidance/ng136. Accessed May 2026.
3. NHS. High blood pressure (hypertension). https://www.nhs.uk/conditions/high-blood-pressure-hypertension. Accessed May 2026.
4. Joint Formulary Committee. British National Formulary (BNF). Telmisartan. BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk. Accessed May 2026.
5. Medicines and Healthcare products Regulatory Agency (MHRA). Yellow Card — report a side effect. https://yellowcard.mhra.gov.uk. Accessed May 2026.

Angiotensin Receptor Blockers (ARBs) and Direct Renin Inhibitors

The table below compares ARB tablets and Rasilez (aliskiren), the only direct renin inhibitor licensed for hypertension in the UK. All act on the renin-angiotensin-aldosterone system (RAAS) and are taken once daily as tablets.

Important: This comparison is for general information only and does not replace medical advice. A prescriber will decide which treatment is suitable for you following an online consultation.