Health Library

Hydrochlorothiazide (By mouth)

Hydrochlorothiazide (hye-droe-klor-oh-THYE-a-zide)

Treats high blood pressure and fluid retention (edema). This medicine is a diuretic (water pill).

Brand Name(s):

When This Medicine Should Not Be Used:

How to Use This Medicine:

Capsule, Liquid, Tablet

• Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.
• Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.
• Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines and foods can affect how hydrochlorothiazide works. Tell your doctor if you are also using any of the following:
  • Cholestyramine, colestipol, digoxin, lithium
  • Insulin or other diabetes medicine
  • NSAIDs (including aspirin, diclofenac, ibuprofen, naproxen, celecoxib)
  • Steroid medicine (including hydrocortisone, methylprednisolone, prednisone, prednisolone, dexamethasone)
• Alcohol, narcotic pain relievers, or sleeping pills may cause you to feel more lightheaded, dizzy, or faint when used with this medicine.

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, heart disease or heart failure, high cholesterol, diabetes, gout, trouble urinating, or lupus.
• This medicine may cause the following problems:
  • Eye or vision problems, including glaucoma, myopia
  • High uric acid in the blood
  • Parathyroid gland problems
  • Increased risk of skin cancer
• This medicine may make you dizzy. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.
• This medicine could lower your blood pressure too much, especially when you first use it or if you are dehydrated. Stand or sit up slowly if you feel lightheaded or dizzy. Alcohol may make this problem worse.
• Tell any doctor or dentist who treats you that you are using this medicine.
• This medicine may make your skin more sensitive to sunlight. Wear sunscreen. Do not use sunlamps or tanning beds.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Blistering, peeling, or red skin rash
• Confusion, weakness, and muscle twitching
• Dry mouth, increased thirst, muscle cramps, nausea or vomiting, uneven heartbeat
• Lightheadedness, dizziness, or fainting
• Sores, reddish patch or irritated area, shiny bump, pink growth, or white, yellow or waxy scar-like area on the skin
• Trouble seeing, eye pain, blurred vision or other vision changes
• Unusual tiredness or weakness

If you notice these less serious side effects, talk with your doctor:

• Headache
• Mild diarrhea, constipation, nausea

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 9/6/2024