Candesartan: NHS information and prescribing guide

Candesartan (candesartan cilexetil) is an angiotensin II receptor blocker (ARB) that is widely prescribed on the NHS for two main conditions.

Licensed indications:

• Hypertension (high blood pressure): NICE (NG136) recommends ARBs such as candesartan as first-line treatment for patients under 55, or as an alternative to ACE inhibitors in patients who develop a cough or other intolerance
• Heart failure: NICE (NG106) recommends candesartan as one of the ARBs of choice for patients with heart failure who cannot tolerate ACE inhibitors. The CHARM trial programme demonstrated benefits across the full spectrum of heart failure

Off-label uses:

• Migraine prevention: candesartan has been studied in randomised trials for migraine prophylaxis and found to be as effective as propranolol. NICE migraine guidelines (CG150) acknowledge ARBs as an option

Candesartan works by blocking the AT1 receptor, preventing angiotensin II from constricting blood vessels and promoting sodium and water retention.

This lowers blood pressure, reduces the workload on the heart and provides kidney protection.

It has a high receptor binding affinity and a long duration of action, providing effective 24-hour blood pressure control from a single daily dose.

Candesartan is taken as a tablet once daily. It can be taken with or without food, at any time of day.

Dosage by indication (BNF recommendations):

• Hypertension: initially 8 mg once daily (4 mg in patients with hepatic impairment or volume depletion). The usual maintenance dose is 8 mg, which can be increased to a maximum of 32 mg once daily if needed
• Heart failure: initially 4 mg once daily, increased at intervals of at least 2 weeks to a target dose of 32 mg once daily, or the maximum tolerated dose

Available strengths: 2 mg, 4 mg, 8 mg, 16 mg and 32 mg tablets.

Practical tips:

• Take candesartan at the same time each day for consistent blood pressure control
• If you miss a dose, take it as soon as you remember unless it is almost time for the next dose. Do not double up
• In heart failure, the dose is increased gradually over several weeks with monitoring of blood pressure, kidney function and potassium
• In hepatic impairment, start at 4 mg and titrate cautiously

Your GP or heart failure nurse will guide the dose titration and arrange the necessary blood tests at each step.

Candesartan is one of the best-tolerated blood pressure medicines. In clinical trials, the rate of side effects was only marginally higher than with a placebo tablet.

Common:

• Dizziness
• Headache
• Respiratory infections (cold-like symptoms)

Uncommon:

• High potassium (hyperkalaemia)
• Low blood pressure
• Back pain or joint pain
• Nausea, fatigue

Rare but serious:

• Angioedema (swelling of face, lips or throat)
• Acute kidney injury
• Severe hypotension
• Liver function abnormalities

For a comprehensive discussion of side effects and how to manage them, visit our candesartan side effects page.

Importantly, candesartan does not usually cause the dry cough that leads many patients to stop ACE inhibitors.

This makes it one of the most popular alternatives for patients who have been unable to tolerate ramipril, lisinopril or enalapril.

Candesartan can interact with several commonly prescribed medicines. Always inform your prescriber and pharmacist about everything you take.

Key interactions:

• ACE inhibitors: should not be combined with candesartan (dual RAAS blockade increases the risk of hyperkalaemia, hypotension and kidney injury)
• Potassium-sparing diuretics (spironolactone, eplerenone, amiloride): increased risk of high potassium; this combination is sometimes clinically necessary (particularly spironolactone in heart failure) but requires close monitoring
• NSAIDs (ibuprofen, naproxen, diclofenac): can reduce the blood pressure effect and increase the risk of kidney injury; use the lowest effective dose for the shortest duration
• Lithium: candesartan can increase lithium levels; more frequent monitoring is needed
• Potassium supplements and salt substitutes: increase the risk of hyperkalaemia
• Other blood pressure medicines: additive blood-pressure-lowering effect; doses may need adjustment

Your pharmacist will check for interactions whenever a new medicine is dispensed. The BNF interactions checker is a useful resource for both patients and clinicians.

Safe prescribing of candesartan requires regular monitoring. NICE and the BNF recommend the following approach.

Before starting:

• Blood pressure measurement
• Renal function (eGFR) and serum electrolytes (including potassium)
• Assessment of volume status (particularly relevant in heart failure patients or those on diuretics)

After starting or changing the dose:

• Blood pressure, renal function and potassium at 1 to 2 weeks
• If the heart failure dose is being titrated, monitoring is required at each dose increase

Long-term monitoring:

• Blood pressure at least annually
• Renal function and potassium at least annually (more frequently in high-risk groups)
• Heart failure patients typically have more regular reviews, including 6-monthly blood tests

Red flags requiring action:

• eGFR decline of more than 25% or creatinine rise of more than 30% from baseline: consider reducing the dose or stopping
• Potassium above 5.5 mmol/L: review interacting medicines and dietary potassium
• Symptomatic hypotension: consider reducing the dose of candesartan or concurrent diuretic

Your GP surgery or heart failure clinic will arrange these tests as part of your regular care.

Candesartan is available as an affordable generic medicine across the NHS.

Prescribing information:

• Available in 2 mg, 4 mg, 8 mg, 16 mg and 32 mg tablets
• Generic candesartan cilexetil is very cost-effective, typically costing the NHS a few pence per tablet
• It is included on local formularies across England, Scotland, Wales and Northern Ireland
• Available on standard NHS prescription

NICE positioning:

• For hypertension (NG136): ARBs such as candesartan are recommended as first-line in certain patient groups and as an alternative to ACE inhibitors
• For heart failure (NG106): candesartan is specifically named as a recommended ARB, supported by the CHARM trial evidence
• For migraine (CG150): ARBs are acknowledged as a prophylactic option, with candesartan having the strongest evidence base in the class

Repeat prescriptions:

Candesartan is typically prescribed as a repeat prescription through the NHS Electronic Prescription Service. Your pharmacy can arrange automatic dispensing so your supply is always ready.

If you have questions about your prescription or would like to discuss your blood pressure treatment, your community pharmacist or GP is always available.