Chlortalidone

About chlortalidone

This belongs to the group of medicines known as thiazide diuretics. Thiazide diuretics are often referred to as water tablets.

Chlortalidone is used to treat hypertension (high blood pressure), ascites (fluid retention around the stomach) and oedema (fluid retention) caused by heart, liver, or kidney failure. It acts on the kidneys to remove excess water from the body by increasing how often you urinate (pass water).

Chlortalidone may also act in the opposite way, reducing how often you urinate (pass water), through an effect on the pituitary gland (part of the brain). For this reason it is sometimes used to treat diabetes insipidus. This type of diabetes is not related to blood sugar, it causes an increase in how much and how often people urinate. chlortalidone will reduce how often people with diabetes insipidus urinate.

Chlortalidone is available in tablet form.

It is also sometimes known as: Hygroton or chlorthalidone. You may notice the use of any of these names on the packaging of your medicine.

Before taking chlortalidone

Before taking chlortalidone make sure your doctor or pharmacist knows:

• if you are pregnant, trying for a baby or breast-feeding
• if you suffer from Addison's disease or diabetes
• if you suffer from or have a history of gout
• if you suffer from porphyria (blood disorder)or systemic lupus erythematosus (SLE)
• if you suffer from hypokalaemia (low blood potassium)
• if you suffer from prostate problems or have problems urinating (passing water)
• if you have ever had an allergic reaction to this or any other medicine
• if you are taking any other medicines, including those available to buy without a prescription, herbal or complementary medicines

How to take chlortalidone

• Always read the manufacturer's information leaflet, if possible, before beginning treatment.
• Take chlortalidone exactly as directed by your doctor or pharmacist.
• This medicine will make you urinate (pass water) more often, unless you suffer from diabetes insipidus, so your doctor or pharmacist will usually advise you to take your dose in the morning so as not to disturb your sleep. If you take more than one dose per day, take the last dose before 6pm in the evening.
• If you miss a dose of chlortalidone take it as soon as you remember. However, if it is after 6pm in the evening skip the missed dose and continue taking it at the usual times. Never take two doses at the same time.
• Chlortalidone is for you. Never give it to others, even if their condition appears to be the same as yours.
• Never take more than the prescribed dose. If you suspect that you or someone else has taken an overdose of chlortalidone contact your doctor or go to the accident and emergency department of your local hospital at once. Always take the container with you, if possible, even if it is empty.

Getting the most from your treatment

• Before taking any 'over-the-counter' medicines, check with your pharmacist which medicines are safe for you to take alongside chlortalidone.
• Keep your regular appointments with your doctor so that your progress can be monitored.
• Avoid excessive consumption of alcohol. Too much alcohol can cause a big drop in blood pressure and may lead to fainting.
• Many patients with high blood pressure do not feel unwell, but left untreated high blood pressure can harm the heart and arteries and damage blood vessels resulting in a heart attack, stroke, heart failure or kidney failure.
• It is very important to take chlortalidone exactly as your doctor has directed and not to stop taking it without speaking to your doctor first, even if you feel quite well.
• It is important to follow any dietary advice that you have been given by your doctor. If you are overweight, your doctor may want you to follow a weight reducing diet.
• Diuretics help you to lose water. On occasions you may lose too much and become dehydrated, leaving you feeling thirsty and your skin looking and feeling dry.
• Chlortalidone may cause a dry mouth. If you experience this try chewing sugar-free gum, sucking sugar-free sweets or pieces of ice. If a dry mouth becomes too troublesome, discuss the problem with your doctor or pharmacist.
• Chlortalidone may cause you to experience faintness or dizziness when getting up from a lying or sitting position. Getting up slowly should help. If this becomes too troublesome ask your pharmacist or doctor for advice.
• Before having any kind of surgery, including dental and emergency treatment, tell the surgeon, dentist or doctor that you are taking chlortalidone.
• If you have diabetes this medicine may affect your blood sugar levels. Test your urine or blood regularly and report any extreme changes to your doctor.
• Chlortalidone may cause your skin to become more sensitive to sunlight than it is usually. Avoid bright sunlight and sunbeds and use a sun cream higher than factor 15 until you know how your skin reacts.

Can chlortalidone cause problems?

Along with their useful effects all medicines can cause unwanted side effects. The risk of suffering from the main side effects is shown below. These usually improve as your body adjusts to the new medicine. Speak to your doctor or pharmacist if any of the following side effects continue or become troublesome.

© EMIS and Cegedim Pharmacy Services Ltd 2006   Updated: 14/02/2006