Candesartan + hydrochlorothiazide

Key points about candesartan + hydrochlorothiazide

  • Candesartan + hydrochlorothiazide is used to treat high blood pressure.
  • There are 2 medicines in one tablet, which work together to control your blood pressure.
  • Candesartan works by relaxing your blood vessels and hydrochlorothiazide helps your body get rid of extra salt (sodium) and water. 
  • Find out how to take it safely and possible side effects.
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Candesartan + hydrochlorothiazide is used to treat high blood pressure (hypertension). These 2 medicines are combined into 1 tablet, and they work together to control your blood pressure. Candesartan works by relaxing your blood vessels and hydrochlorothiazide helps your body get rid of extra salt (sodium) and water. 

Tablet strengths

In Aotearoa New Zealand there are 3 strengths of the candesartan + hydrochlorothiazide tablet:

  • Candesartan 16mg + hydrochlorothiazide 12.5mg. 
  • Candesartan 32mg + hydrochlorothiazide 12.5mg.
  • Candesartan 32mg + hydrochlorothiazide 25mg.


  • The usual dose is 1 tablet once a day. 
  • Always take your medicine exactly as your healthcare provider has told you.
  • The pharmacy label on your medicine will tell you how much to take, how often to take it and any special instructions.
  • You may not feel any different after you take candesartan + hydrochlorothiazide but the medicine will be having an effect in your body. It may take 4 to 6 weeks to reach its maximum effect on your blood pressure.
  • The amount of medicine you need to take may change depending on how your body responds so it's important to see your healthcare provider for regular checks.

Note: It's common to be taking more than 1 medicine for your blood pressure because taking more medicines of low strength lessens the chance of side effects compared to taking a larger dose of a single medicine.

  • Take your dose once a day, at the time of day most suitable for you. You can take it with or without food.
  • Stay hydrated and make sure you drink enough water. This is especially important during exercise and hot weather, which can increase your risk of dehydration. If you don't drink enough water you may feel faint, light-headed, or sick. Note: follow the advice of your healthcare provider if you've been asked to restrict your fluid intake.
  • Take your medicines regularly. If you forget to take your dose, take it as soon as you remember that day. But if it's nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.

Be careful when taking pain relief medicines

It’s very important to not take any anti-inflammatory pain relief medications such as ibuprofen (eg, Nurofen) and diclofenac (eg, Voltaren) while you are taking candesartan + hydrochlorothiazide. This combination can be very harmful to your kidneys and can cause acute kidney injury.(external link) You have a higher risk of harm to your kidneys if you are an older person or are dehydrated. Ask your doctor or pharmacist for safer pain relief options. Read more about NSAIDs and protecting your kidneys.

Examples of NSAIDs
  • ibuprofen (Ibugesic, I-Profen, Nurofen)
  • diclofenac (Voltaren)
  • naproxen (Naprogesic, Noflam, Naprosyn)
  • mefenamic acid (Ponstan)
  • celecoxib (Celebrex)
  • Protection against the sun. Hydrochlorothiazide can make your skin more sensitive to the sun. Always cover your skin and apply sunscreen when outside to protect yourself from too much sunlight. Read more about non-melanoma skin cancer, sun safety advice, and how to check for skin cancer.

  • Have a sick day plan. If you have diarrhoea (runny poo) or vomiting (being sick) from a stomach bug, or have dehydration from other causes, it’s important to let your doctor know. They may advise you to stop taking candesartan + hydrochlorothiazide for a few days and restart it when you feel better. The reason for this is that this medicine can increase the amount of potassium in your blood, particularly if you are dehydrated.

  • Limit alcohol while taking candesartan + hydrochlorothiazide. Regularly drinking large amounts of alcohol increases your blood pressure. Have at least 2 alcohol-free days a week.
  • Pregnant or planning a pregnancy. Don't take candesartan + hydrochlorothiazide if you are pregnant (hapū), or if there is a chance you could become pregnant. Candesartan can cause birth defects and is harmful to unborn babies. Talk to your healthcare provider about other blood pressure medicines you can take instead.

  • Visit your healthcare provider regularly. You will need regular blood tests to check your potassium levels and your kidney function.

Like all medicines, candesartan and hydrochlorothiazide can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Dizziness
  • Feeling lightheaded
  • Feeling faint when you stand up
  • This is quite common when you first start this medicine and usually goes away with time.
  • These side effects put you at risk of falls and injuries, especially if you are older.
  • Stand up slowly from either lying down or sitting. If you do feel dizzy, sit down or lie down for a few moments.
  • Be careful when driving or using tools until you know how this medicine affects you.
  • Avoid alcohol.
  • Tell your doctor if any of these side effects continue to bother you.
  • Headache
  • This is quite common when you first start this medicine and usually goes away with time. Tell your doctor if this bothers you.
  • Muscle cramps
  • Muscle weakness
  • These are less common and if they happen without any reason, may be a sign of high potassium levels.
  • Tell your doctor – you may need a blood test to check the amount of potassium in your blood. 
  • Signs of an allergic reaction such as skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing, eg, chest tightness or wheezing
  • Allergic reactions are rare but serious.
  • Tell your doctor immediately or ring Healthline 0800 611 116.
  • Signs of problems with your liver such as yellowing of the skin or eyes, dark urine, pain in the abdomen
  • Liver problems are rare but serious.
  • Tell your doctor immediately or ring Healthline 0800 611 116.
For more information on side effects, see the Medsafe consumer information leaflet below.

Did you know that you can report a medicine side effect to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.(external link)

The following links have more information on candesartan and hydrochlorothiazide:

Candesartan and hydrochlorothiazide(external link) NZ Formulary Patient Information, NZ


  1. Candesartan + hydrochlorothiazide(external link) NZ Formulary, NZ
  2. Hypertension in adults: the silent killer(external link) BPAC, 2023
  3. The Triple Whammy(external link) (ACEi or ARB + diuretics + NSAIDs or COX2s) SafeRx, 2019

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Credits: Healthify He Puna Waiora editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist.

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