Chlorothiazide - oral

Patient Medicine Information
Why do I need this medicine?
Chlorothiazide helps to keep your blood pressure under control.

This medicine is also used together with other medicines to treat water retention caused by heart failure, liver or kidney disease. Water retention may be noticed as swelling of the feet, ankles, lower leg and hands or shortness of breath. For this reason, it is commonly known as a "water pill".

Chlorothiazide may be used to treat other conditions as decided by your doctor.
How do I take this medicine?
Take Chlorothiazide exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

This medicine should be taken together with food or immediately after a meal. Try to take it at the same time each day.

You may need to pass urine more often while being treated with Chlorothiazide. Take this medicine early in the day, preferably in the morning. If your doctor has told you to take it twice a day, take the last dose in the late afternoon. This is to avoid you from waking up frequently at night to go to the toilet.

Chlorothiazide must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
What should I do if I have forgotten to take this medicine?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.
When should I not use this medicine?
Alert your doctor if you are unable to pass urine as Chlorothiazide may not be suitable for you.

Do not take this medicine if you ever had an allergic reaction (rashes, breathlessness, swollen eyes) to sulfa-containing antibiotics such as sulfamethoxazole, sulfasalazine and sulfisoxazole.
What should I take note of while taking this medicine?
Inform your doctor if you have the following conditions:

- diabetes
- gout
- liver disease
- kidney disease
- high cholesterol levels
- an autoimmune disease that causes inflammation called systemic lupus erythematosus (SLE)

Let your doctor know if you are pregnant or breastfeeding.

If you are going for an operation, including minor surgery and dental work, inform your doctor or dentist that you are taking Chlorothiazide.

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medicine regularly. He may also need to do routine blood tests while you are being treated with Chlorothiazide.

What lifestyle changes can I make to improve my blood pressure?

Regular exercise and eating a healthy diet will help lower your blood pressure and improve your overall health. Engage in physical activity (e.g. walking) at least 30 to 60 minutes on most days of the week. If you have not exercised for a long time, start with light exercises such as slow walks. Speak to your doctor about what type of exercise would be suitable for you.

Follow a healthy diet plan by eating more fruits, vegetables, whole grains, and low-fat dairy products. Reduce your intake of foods high in saturated fat, cholesterol, and sodium. Cutting down on deep-fried foods and using less salt when cooking can kick-start your healthy diet.

If you smoke, you should try to quit. Smoking is harmful to your blood pressure, heart, and overall health. Speak to your doctor or pharmacist about ways to kick your smoking habit.
What side effects could I experience?
Chlorothiazide may cause dizziness and blurred vision. If affected, do not drive or take part in any activity in which you need to be alert. You may also feel dizzy when getting up from a sitting or lying down position, especially if you are taking this medicine for the first time. This is normal and should improve as you get used to the medicine. It will help if you get up slowly.

Other side effects include any of the following: headache, rash, stomach discomfort, loss of appetite, nausea, vomiting, weakness, and sensitivity to sunlight. Apply sunscreen when going outdoors and avoid direct or prolonged exposure to sunlight and UV lamps.

You may need to pass urine more often while you are being treated with this medicine. As your body adjusts to the medicine, this urination effect should also decrease.

Some side effects may need immediate medical help. Alert your doctor quickly if you experience rashes with skin peeling or blisters or yellowing of the skin or eyes with abdominal pain or persistent tiredness, nausea or vomiting.

Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I take this with other medicines?
Inform your doctor and pharmacist if you are taking any of these medicines:

- medicines for diabetes e.g. insulin, metformin, glipizide
- medicines for high blood pressure e.g. captopril
- colestyramine (cholesterol-lowering medicine)
- lithium (medicine for mood disorders)

This list does not include all medicines that may interact with Chlorothiazide.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicine, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
It may be helpful to discuss your amount of intake of salt and calcium with your doctor or dietitian as a change in diet may help improve your symptoms.

Your doctor may give you potassium supplements while you are being treated with Chlorothiazide.

Alternatively, he may tell you to eat more of foods that are high in potassium, such as orange juice, bananas or prunes.
How should I store this medicine?
Store in a cool, dry place away from the reach of children.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on chlorothiazide - oral and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by
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