What are water tablets for high blood pressure?

(Bendroflumethiazide, Chlortalidone, Cyclopenthiazide, Indapamide, Xipamide)

These tablets increase the amount of water that you pass out from your kidneys. They are sometimes called 'water tablets'.  This decision aid focuses on a group of water tablets used to treat high blood pressure. The pharmacy name for these tablets is Thiazide Diuretics.

Find out more at: 

https://patient.info/health/thiazide-diuretics#nav-1

How likely are these tablets to help me?

Key

  • This grey face represents the number of people in the survey group.
  • This green face represents the one person in the survey group that the medicine has helped.

Research  suggests that the benefits of these medicines vary with age and level of risk:

 

For people over 80 years old:

  • In a group of 70 people with high blood pressure, taking thiazide diuretics will prevent  one person (on average) from death due to heart disease or stroke, and from non-fatal illnesses including heart attack,  congestive heart failure, sudden cardiac arrest, ruptured arteries, fatal and transient ischaemic attacks.  There is very limited evidence of impact on death from other causes.

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  • In a group of  32 people with high blood pressure at high risk of events caused by heart conditions,  taking thiazide diuretics will prevent  one person (on average) from death due to heart disease or stroke, and from non-fatal illnesses including heart attack,  congestive heart failure, sudden cardiac arrest, ruptured arteries, fatal and transient ischaemic attacks.There is very limited evidence of impact on death from other causes. 

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For people over 60 years old:

  • In a group of 104 people with high blood pressure, taking thiazide diuretics will prevent  one person (on average) from death due to heart disease or stroke, and from non-fatal illnesses including heart attack,  congestive heart failure, sudden cardiac arrest, ruptured arteries, fatal and transient ischaemic attacks.  

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  • In a group of 41 people with high blood pressure, and other high risk factors for heart-related illness, taking thiazide diuretics will prevent  one person (on average) from death due to heart disease or stroke, and from non-fatal illnesses including heart attack,  congestive heart failure, sudden cardiac arrest, ruptured arteries, fatal and transient ischaemic attacks.

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What are the possible risks of taking these medicines?

You can discuss with your health professional  the possible side effects and other risks these medicines might have.

Side-effects are unwanted affects that can happen to your body when taking a medicine.  

Not everyone will get side-effects. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects persist or worry you.

The most common side-effects of these medicines, are:

  • Changes in the levels of sugar in your blood.
  • Changes in the balance of salts in your blood. In severe cases this may cause confusion.
  • Upset stomach
  • Dizziness
  • Impotence (usually reversible on stopping the medicines)
  • Skin sensitivity to sunlight.

You can find out more about the side effects of these medicines at 

https://patient.info/health/thiazide-diuretics#nav-3