Angiotensin II receptor blocker (ARB) Pregnancy: Not recommended in the first trimester and contraindicated in the second and third trimesters of pregnancy. Exposure from the second trimester can cause human fetotoxicity (reduced renal function, oligohydramnios, skull ossification retardation) and neonatal toxicity (renal failure, hypotension, hyperkalaemia). Stop treatment immediately when pregnancy is diagnosed. Not recommended during breast-feeding.

Telmisartan

Brand names: Micardis

Telmisartan is a long-acting angiotensin-II receptor blocker (ARB) used for hypertension and to reduce cardiovascular risk in selected patients. It is a useful alternative when an ACE-inhibitor cough is troublesome.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 40 mg

Route: Oral

Frequency: Once daily

Max: 80 mg once daily

Essential hypertension: usually effective dose 40 mg once daily; some patients benefit at 20 mg; if target blood pressure not achieved, increase to a maximum of 80 mg once daily or combine with a thiazide-type diuretic. Maximum antihypertensive effect is generally attained 4–8 weeks after starting. Cardiovascular prevention: recommended dose 80 mg once daily. Mild–moderate hepatic impairment: do not exceed 40 mg once daily (contraindicated in severe hepatic impairment). Taken with or without food. Not established in children/adolescents under 18 years.

Dose adjustments

Renal

Severe renal impairment or haemodialysis: a lower starting dose of 20 mg is recommended. No dose adjustment required for mild to moderate renal impairment.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

May be administered with or without food ( 2.1 ) When used for cardiovascular risk reduction, monitoring of blood pressure is recommended, and if appropriate, adjustment of medications that lower blood pressure may be necessary ( 2.2 ) Indication Starting Dose Dose Range Hypertension ( 2.1 ) 40 mg once daily 40 to 80 mg once daily Cardiovascular Risk Reduction ( 2.2 ) 80 mg once daily 80 mg once daily 2.1 Hypertension Dosage must be individualized. The usual starting dose of telmisartan tablets is 40 mg once a day. Blood pressure response is dose-related over the range of 20 to 80 mg [see Clinical Studies (14.1) ]. Most of the antihypertensive effect is apparent within 2 weeks and maximal …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-06-05. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Second and third trimesters of pregnancy
Biliary obstructive disorders
Severe hepatic impairment
Concomitant use with aliskiren-containing products in patients with diabetes mellitus or renal impairment (GFR <60 ml/min/1.73 m2)

Side effects

Hyperkalaemia (uncommon)
Hypotension and orthostatic hypotension (uncommon)
Vertigo (uncommon); syncope (rare)
Urinary tract infection and upper respiratory tract infection (uncommon)
Anaphylactic reaction and angioedema (rare)

Interactions

Aliskiren-containing products: contraindicated in diabetes mellitus or renal impairment
Dual RAAS blockade (concomitant ACE inhibitors, angiotensin II receptor blockers or aliskiren): not recommended — increased risk of hypotension, hyperkalaemia and decreased renal function
Agents that raise serum potassium: increased risk of hyperkalaemia

Clinical monograph

How it works

It selectively blocks the angiotensin II type 1 (AT1) receptor, preventing angiotensin II-mediated vasoconstriction and aldosterone release, thereby lowering blood pressure.

Prescribing in practice

Avoid in pregnancy — ARBs are associated with fetal toxicity; women planning pregnancy should be switched to an alternative.
Hyperkalaemia and deterioration in renal function can occur, particularly with renal impairment, in renal artery stenosis, or alongside potassium-sparing diuretics, potassium supplements or NSAIDs.
Do not combine an ARB with an ACE inhibitor; symptomatic hypotension may occur, especially in volume-depleted patients (e.g. those on high-dose diuretics).

Monitoring

Check renal function, electrolytes (including potassium) and blood pressure before starting and after initiation or dose changes. Monitor blood pressure for treatment response and watch renal function closely in those at higher risk of deterioration.

Counselling the patient

Tell us at once if you become pregnant or are planning pregnancy, as this medicine must be stopped.
Avoid potassium-based salt substitutes and do not start potassium supplements unless advised.
Dizziness can occur, particularly with the first doses; rise slowly from sitting or lying.

Evidence & guidelines

ARBs are a guideline-recommended option for hypertension (NICE NG136).

Reference: NICE NG136; ESC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Valsartan · Angiotensin II receptor blocker (ARB)

Pathways