Chlorothiazide (oral/injection)

Chlorothiazide is a diuretic (water pill) that helps treat fluid retention (edema) in people with congestive heart failure, cirrhosis of the liver, or kidney disorders, or edema caused by taking steroids or estrogen.

Chlorothiazide is also used to treat high blood pressure (hypertension).

Chlorothiazide may also be used for reasons not mentioned in this medication guide.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may change your dose from time to time. Use the medicine exactly as directed.

Shake the oral suspension (liquid) before measuring a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Chlorothiazide injection is given as an infusion into a vein. A healthcare provider will administer this injection if you cannot take the medicine by mouth.

Tell your caregivers if you experience any burning, pain, or swelling around the IV needle when chlorothiazide is injected.

You may need to follow a special diet to prevent your potassium levels from getting too low. Follow all instructions from your doctor or dietitian. Learn about the foods to eat or avoid to help manage your condition.

Your blood pressure will need to be checked frequently.

Certain factors can cause your blood pressure to drop too low. This includes vomiting, diarrhea, or heavy sweating. Call your doctor if you are experiencing vomiting or diarrhea.

This medicine can affect the results of some medical tests. Inform any doctor who treats you that you are using chlorothiazide.

If you have high blood pressure, continue using this medicine even if you feel fine. High blood pressure often does not have symptoms. You may need to take blood pressure medicine for the rest of your life.

Store at room temperature away from moisture, heat, and light.

You should not use chlorothiazide if you cannot urinate, or if you are allergic to sulfa drugs.

You should not use chlorothiazide if you are allergic to it, or if:

• you are unable to urinate; or
• you are allergic to sulfa drugs.

Tell your doctor if you have ever had:

• kidney disease;
• liver disease;
• asthma;
• gout;
• diabetes;
• lupus; or
• high cholesterol or triglycerides (a type of fat in the blood).

It is not known whether chlorothiazide will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

You should not breast-feed while using this medicine.

Chlorothiazide is not approved for use by anyone younger than 18 years old.

Get emergency medical help if you notice signs of an allergic reaction (such as hives, trouble breathing, swelling in your face or throat) or a severe skin reaction (including fever, sore throat, burning eyes, skin pain, or a red or purple skin rash with blistering and peeling).

Chlorothiazide can cause serious side effects. Contact your doctor immediately if you experience:

• a feeling of light-headedness, as if you might faint;
• very little or no urination;
• severe pain in your upper stomach that spreads to your back;
• low blood cell counts—symptoms include pale or yellowed skin, dark urine, fever, easy bruising or bleeding; or
• signs of an electrolyte imbalance—such as dry mouth, increased thirst or urination, confusion, vomiting, constipation, muscle pain or weakness, leg cramps, dizziness, drowsiness, lack of energy, feeling restless, rapid heartbeats, or a tingling sensation.

Common side effects of chlorothiazide may include:

• dizziness or a spinning sensation;
• numbness or tingling;
• diarrhea, constipation, or stomach cramps;
• blurred vision;
• muscle spasms; or
• impotence or sexual problems.

This is not a complete list of side effects, and others may occur. Contact your doctor for medical advice about side effects. You can report side effects to the FDA at 1-800-FDA-1088.

Take the medicine as soon as possible, but skip the missed dose if it is nearly time for your next dose. Do not take two doses at once.

Seek emergency medical help or call the Poison Help line at 1-800-222-1222.

Signs of an overdose may include confusion, an uneven heart rate, extreme thirst, more frequent urination, muscle weakness, feeling very thirsty or hot, or being unable to urinate.

Drinking alcohol while taking chlorothiazide can lead to side effects.

Do not get up too quickly from a sitting or lying position, or you may feel dizzy.

Do not become overheated or dehydrated during exercise, in hot weather, or by not drinking enough fluids. Follow your doctor's directions about the type and amount of liquids you should drink. In some situations, drinking too much liquid can be just as dangerous as not drinking enough.

Using chlorothiazide with other medications that cause dizziness can make this effect worse. Talk to your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Inform your doctor about all your other medications, especially:

• other blood pressure medications;
• cholestyramine or colestipol;
• lithium;
• insulin or oral diabetes medicine;
• steroid medicine; or
• NSAIDs (nonsteroidal anti-inflammatory drugs)--aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others.

This list is not complete. Other medications may affect chlorothiazide, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

• Should you use a diuretic with diazoxide?