Candesartan: NHS information and prescribing guide

Candesartan (candesartan cilexetil) is an angiotensin II receptor blocker (ARB). The NHS widely prescribes it for two main conditions.

Licensed indications:

• Hypertension (high blood pressure): NICE (NG136) suggests ARBs like candesartan as a first choice for patients under 55. It is also an option if patients cannot tolerate ACE inhibitors due to a cough or other issues.
• Heart failure: NICE (NG106) recommends candesartan. It is one of the ARBs chosen for heart failure patients who cannot tolerate ACE inhibitors. The CHARM trial programme showed benefits for all types of heart failure.

Off-label uses:

• Migraine prevention: Studies have looked at candesartan for preventing migraines. Randomised trials found it as effective as propranolol. NICE migraine guidelines (CG150) recognise ARBs as a possible treatment.

Candesartan works by blocking the AT1 receptor. This stops angiotensin II from narrowing blood vessels. It also prevents the body from holding onto too much sodium and water.

This action lowers blood pressure. It also reduces the heart's workload and protects the kidneys.

It binds strongly to the receptor and works for a long time. A single daily dose gives effective 24-hour blood pressure control.

You take candesartan as a tablet once a day. You can take it with or without food. You can take it at any time of day.

Dosage by indication (BNF recommendations):

• Hypertension: Start with 8 mg once daily. If you have liver problems or are volume depleted, start with 4 mg. The usual dose is 8 mg. This can go up to a maximum of 32 mg once daily if needed.
• Heart failure: Start with 4 mg once daily. Increase the dose every 2 weeks or more. Aim for 32 mg once daily, or the highest dose you can tolerate.

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

Practical tips:

• Take candesartan at the same time each day. This helps keep your blood pressure steady.
• If you miss a dose, take it when you remember. Do this unless it is almost time for your next dose. Do not take a double dose.
• For heart failure, the dose increases slowly over several weeks. Your blood pressure, kidney function, and potassium levels will be checked.
• If you have liver problems, start at 4 mg. Increase the dose carefully.

Your GP or heart failure nurse will help you adjust the dose. They will also arrange blood tests at each step.

Candesartan is one of the best-tolerated blood pressure medicines. In studies, side effects were only slightly more common than with a dummy tablet.

Common:

• Dizziness
• Headache
• Respiratory infections (like a cold)

Uncommon:

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

Rare but serious:

• Angioedema (swelling of the face, lips or throat)
• Acute kidney injury
• Severe low blood pressure
• Liver function problems

For full details on side effects and how to manage them, see our candesartan side effects page.

Candesartan usually does not cause the dry cough. This cough makes many patients stop ACE inhibitors. This makes candesartan a popular choice.

It is for patients who cannot tolerate ramipril, lisinopril, or enalapril.

Candesartan can interact with several common medicines. Always tell your prescriber and pharmacist about all medicines you take.

Key interactions:

• ACE inhibitors: Do not combine these with candesartan. This 'dual RAAS blockade' raises the risk of high potassium, low blood pressure, and kidney damage.
• Potassium-sparing diuretics (spironolactone, eplerenone, amiloride): These increase the risk of high potassium. This combination is sometimes needed, especially spironolactone for heart failure. However, it needs close monitoring.
• NSAIDs (ibuprofen, naproxen, diclofenac): These can reduce the blood pressure effect. They also increase the risk of kidney damage. Use the lowest effective dose for the shortest time.
• Lithium: Candesartan can increase lithium levels. You will need more frequent monitoring.
• Potassium supplements and salt substitutes: These increase the risk of high potassium.
• Other blood pressure medicines: These can have an added blood-pressure-lowering effect. Your doses may need adjusting.

Your pharmacist will check for interactions when you get a new medicine. The BNF interactions checker is a helpful tool for patients and doctors.

You need regular monitoring to safely take candesartan. NICE and the BNF recommend the following steps.

Before starting:

• Measure your blood pressure.
• Check your kidney function (eGFR) and blood electrolytes (including potassium).
• Assess your fluid status. This is especially important for heart failure patients or those taking diuretics.

After starting or changing the dose:

• Check blood pressure, kidney function, and potassium at 1 to 2 weeks.
• If you are increasing the heart failure dose, monitoring is needed with each increase.

Long-term monitoring:

• Check blood pressure at least once a year.
• Check kidney function and potassium at least once a year. High-risk groups need more frequent checks.
• Heart failure patients usually have more regular reviews. This includes blood tests every 6 months.

Red flags needing action:

• eGFR drops by more than 25% or creatinine rises by more than 30% from your starting level: Think about lowering the dose or stopping the medicine.
• Potassium above 5.5 mmol/L: Review other medicines you take and your diet's potassium content.
• Low blood pressure with symptoms: Consider lowering the dose of candesartan or any diuretic you take.

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

Candesartan is an affordable generic medicine. It is widely available across the NHS.

Prescribing information:

• It comes in 2 mg, 4 mg, 8 mg, 16 mg, and 32 mg tablets.
• Generic candesartan cilexetil is very cost-effective. It usually costs the NHS only a few pence per tablet.
• It is on local lists of approved medicines across England, Scotland, Wales, and Northern Ireland.
• You can get it on a standard NHS prescription.

NICE positioning:

• For hypertension (NG136): ARBs like candesartan are first-line for some patient groups. They are also an alternative to ACE inhibitors.
• For heart failure (NG106): Candesartan is specifically named as a recommended ARB. The CHARM trial evidence supports this.
• For migraine (CG150): ARBs are recognised as a prevention option. Candesartan has the strongest evidence in its class for this use.

Repeat prescriptions:

Candesartan is usually a repeat prescription. You can get it through the NHS Electronic Prescription Service. Your pharmacy can set up automatic dispensing. This ensures your supply is always ready.

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