Chlorothiazide treats high blood pressure and fluid retention. It increases the amount of salt and water the kidneys remove from the blood.
Chlorothiazide is a prescription medication used to treat high blood pressure and fluid retention caused by congestive heart failure and other conditions. Chlorothiazide belongs to a group of drugs called diuretics ("water pills") which help the body get rid of excess fluid by increasing the amount of salt and water the kidneys remove from the blood.
This medication comes in tablet and liquid form and is taken once or twice daily, with or without food.
Chlorothiazide also comes in an injectable form to be given directly into a vein (IV) by a healthcare provider.
Common side effects of chlorothiazide include headache, diarrhea, and nausea. This medication can also cause dizziness. Do not drive or operate heavy machinery until you know how it affects you.
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Chlorothiazide Cautionary Labels
Uses of Chlorothiazide
Chlorothiazide is a prescription medication used to treat high blood pressure and fluid retention caused by congestive heart failure, hepatic cirrhosis, kidney disease, estrogen, and corticosteroids.
This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.
Chlorothiazide Brand Names
Chlorothiazide Drug Class
Chlorothiazide is part of the drug class:
Side Effects of Chlorothiazide
Common side effects include:
- loss of appetite
- muscle weakness or spasm
- loss of energy
- blurred vision
- nervousness or restlessness
This is not a complete list of chlorothiazide side effects. Ask your doctor or pharmacist for more information.
Serious side effects can occur. See "Drug Precautions" section.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:
- other medications for high blood pressure
- nonsteroidal anti-inflammatory medications such as ibuprofen (Motrin) or naproxen (Aleve) and salicylates
- corticosteroids such as prednisone, hydrocortisone (Cortef), and dexamethasone (Decadron, Dexone, Hexadrol)
- lithium (Eskalith, Lithobid)
- medications for diabetes
- probenecid (Benemid)
- barbiturates such as amobarbital (Amytal), butalbital (Fioricet, Fiorinal), phenobarbital (Luminal) and others
- digoxin (Digitek, Lanoxin)
- cholestyramine (Prevalite, Questran, Questran Light)
- colestipol (Colestid)
This is not a complete list of chlorothiazide drug interactions. Ask your doctor or pharmacist for more information.
Chlorothiazide can cause serious side effects including:
- electrolyte imbalance. This medication may affect electrolytes including sodium and potassium. Your doctor will check these levels using a blood test. Warning signs of electrolyte imbalance include:
- dry mouth
- lack of energy
- muscle pains or cramps
- muscle fatigue
- low blood pressure
- decreased urination
- fast heart rate
- nausea and vomiting
- worsening of kidney disease
- worsening of gout
- sensitivity reactions. Patients with a history of asthma or allergy may experience sensitivity reactions.
- high blood glucose "sugar" concentrations in people with diabetes
- systemic lupus erythematosus (SLE or lupus) or worsening of lupus
- hepatic coma. Thiazide diuretics, like chlorothiazide, should be used with caution in people with liver disease.
This medication may cause drowsiness or dizziness. Do not drive or operate heavy machinery until you know how it affects you.
Do not take chlorothiazide if you:
- are allergic to chlorothiazide or any other ingredient in this medication
- are allergic to "sulfa" drugs
- are unable to produce urine
Chlorothiazide Food Interactions
Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of chlorothiazide, there are no specific foods that you must exclude from your diet when receiving this medication.
Before taking chlorothiazide, tell your doctor about all of your medical conditions. Especially tell your doctor if you:
- have liver disease
- have kidney disease
- have diabetes
- have asthma
- have systemic lupus erythematosus (SLE)
- have gout
- have electrolyte imbalances
- are allergic to sulfa medications or any other medications
- are pregnant or breastfeeding
Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.
Chlorothiazide and Pregnancy
Tell your doctor if you are pregnant or plan to become pregnant.
The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.
Chlorothiazide falls into category C. In animals studies, pregnant animals were given this medication and had some babies born with problems. There are no well-controlled studies that have been done in humans with chlorothiazide, though. Therefore, this medication may be used if the potential benefits to the mother outweigh the potential risks to the unborn child.
Chlorothiazide and Lactation
Tell your doctor if you are breastfeeding or plan to breastfeed.
Chlorothiazide has been detected in human breast milk. Because of the possibility for adverse reactions in nursing infants from chlorothiazide, a choice should be made whether to stop nursing or to stop use of chlorothiazide. The importance of the drug to the mother should be considered.
- Take chlorothiazide exactly as prescribed.
- This medication comes in tablet and liquid form and is usually taken once or twice daily.
- Be sure to shake the liquid form (chlorothiazide oral suspension) thoroughly each time before use.
- Chlorothiazide can be taken with or without food.
- Chlorothiazide also comes in an injectable form to be given directly into a vein (IV) by a healthcare provider.
- Because chlorothiazide increases urination, it is best taken in the morning to avoid having to get up in the night to urinate. If you take it more than once a day, take your last dose by late afternoon.
- If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose.
Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.
The chlorothiazide dose your doctor recommends will be based on:
- the condition being treated
- other medical conditions you have
- other medications you are taking
- how you respond to this medication
- body weight (children)
- For Fluid Retention
- The usual adult dosage is 500 mg to 1000 mg (10 mL to 20 mL of liquid suspension) once or twice a day.
- For High Blood Pressure
- The usual adult starting dosage is 500 mg to 1000 mg (10 mL to 20 mL of liquid suspension) a day as a single or divided dose. Dosage is increased or decreased according to blood pressure response. Rarely some patients may require up to 2000 mg (40 mL) a day in divided doses.
- Infants and Children - For Fluid Retention and High Blood Pressure
- The usual pediatric dosage is 5 mg to 10 mg per pound (10 mg/kg to 20 mg/kg) per day in single or two divided doses, not to exceed 375 mg per day (2.5 mL to 7.5 mL or ½ to 1½ teaspoonfuls of the oral suspension daily) in infants up to 2 years of age or 1000 mg per day in children 2 to 12 years of age. In infants less than 6 months of age, doses up to 15 mg per pound (30 mg/kg) per day in two divided doses may be required.
- Therapy should be individualized according to how you respond to this medication. Use the smallest dosage necessary to achieve the required response.
If you take too much chlorothiazide call your doctor or local Poison Control Center, or seek emergency medical attention right away.
- Keep this and all medications out of the reach of children.