NZ Formulary

Chlortalidone

klor-tal-ih-dohn

What does it do?

Chlortalidone is used to treat high blood pressure and reduce excess fluid in your body.

Before you start

  • Tell your doctor if you have kidney problems, or gout.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

How should you take it?

Take chlortalidone regularly as directed with a glass of water. You can take it with or without food.

What if you forget a dose?

If it is nearly time for your next dose, skip the missed dose and take your next dose at the usual time. Otherwise, take the missed dose as soon as you remember. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with chlortalidone including:

  • anti-inflammatories, such as diclofenac (e.g. Voltaren®), ibuprofen (e.g. Nurofen®), or aspirin (e.g. Disprin®, in doses used for pain relief). These can also be found in some cold and flu medicines (e.g. Nurofen Cold and Flu®).
  • calcium supplements (e.g. Calci-Tab®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Changes in heartbeat, muscle cramps or weakness

Confusion or drowsiness (may be signs of low sodium)

Changes in vision

Tell your doctor

More sensitive to sunlight (sunburn or rash)

Gout attack

Trouble getting or keeping an erection

Tell your doctor if troublesome

Symptoms of low blood pressure such as dizziness or fainting

Stand up slowly. If it continues, or is severe, tell your doctor

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Protect yourself from too much sunlight while being treated with chlortalidone. Always cover up and apply a thick layer of broad spectrum sunscreen (at least SPF 30) when outside. Do not use sunbeds.
  • You may need blood tests while taking chlortalidone to check the amount of potassium and sodium in your blood, and to see how well your kidneys are working.