Hydrochlorothiazide Tablet | Side Effects, Dosage, Uses & More
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Generic Name:

hydrochlorothiazide, Oral tablet

All Brands

  • Esidrix (Discontinued)
  • HydroDIURIL (Discontinued)
  • Oretic (Discontinued)
A discontinued drug is a drug that has been taken off the market due to safety issues, shortage of raw materials, or low market demand.
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Highlights for hydrochlorothiazide

Oral tablet
1

Hydrochlorothiazide is used to treat high blood pressure and swelling caused by heart failure, liver damage, and certain medications.

2

This drug comes as a tablet or capsule that you take by mouth. It also comes as a solution you take by mouth.

3

Hydrochlorothiazide is available as the brand-name drug Microzide. It’s also available as a generic drug.

IMPORTANT INFORMATION

Fluids/electrolytes

Your doctor should check your fluid and electrolytes when you’re taking hydrochlorothiazide. This drug can cause a fluid or electrolyte imbalance. Symptoms include:

  • dry mouth
  • thirst
  • weakness
  • tiredness
  • drowsiness
  • restlessness
  • confusion
  • seizures
  • muscle pain or cramps
  • muscle fatigue
  • lower than normal blood pressure
  • higher than normal heart rate
  • producing less urine than normal
  • nausea or vomiting

Sulfonamide allergy

If you’re allergic to medications that contain sulfonamide, you shouldn’t take this drug.

Vision problems

Hydrochlorothiazide can cause blurred vision and glaucoma. Symptoms include eye pain and trouble seeing. These problems often occur within hours to weeks after starting this medication. Tell your doctor if you have any vision problems. If left untreated, it can lead to permanent vision loss. If you have blurred vision, it may return to normal after you stop taking this medication.

What is hydrochlorothiazide?

Hydrochlorothiazide is a prescription drug. It’s available as a tablet, capsule, or solution that you take by mouth. 

Hydrochlorothiazide is available as the brand-name drug Microzide. It is also available as a generic drug. Generic drugs usually cost less. In some cases, they may not be available in every strength or form as the brand-name version. 

Hydrochlorothiazide may be used as part of a combination therapy. This means you may need to take with other blood pressure medications. This is more likely if you have severe high blood pressure.

Why it's used

Hydrochlorothiazide is used to treat high blood pressure. This drug is given either alone or with other medicines if you have a severe form of high blood pressure.

More Details

How it works

Hydrochlorothiazide belongs to a class of drugs called thiazide diuretics. A class of drugs refers to medications that work similarly. They have a similar chemical structure and are often used to treat similar conditions.

Why it's used

Hydrochlorothiazide is used to treat high blood pressure. This drug is given either alone or with other medicines if you have a severe form of high blood pressure.

Hydrochlorothiazide is used to treat swelling that’s caused by heart failure, liver damage (cirrhosis), and taking certain medications (corticosteroids or estrogens). It may also help swelling that’s caused by kidney problems. This drug is used in combination with other medications to reduce swelling.

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hydrochlorothiazide Side Effects

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More Common Side Effects

The most common side effects that occur with hydrochlorothiazide include:

  • lower than normal blood pressure (especially when standing up from sitting or lying down)

  • dizziness

  • headache

  • weakness

  • trouble getting or keeping an erection (erectile dysfunction)

  • tingling in your hands, legs, and feet

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious Side Effects

If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life threatening or if you think you’re experiencing a medical emergency, call 9-1-1.

  • severe skin reactions such as Stevens-Johnson syndrome and exfoliative dermatitis. Symptoms include:

    • painful skin rash
    • skin peeling and blisters
    • fever
    • mouth sores
  • kidney failure. Symptoms include:

    • weakness
    • shortness of breath
    • tiredness
    • confusion
    • abnormal heart rate or chest pain
    • producing less urine than normal
    • increased swelling in your legs, ankles, or feet
  • blurred vision. Symptoms include:

    • eye pain
    • trouble seeing
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Hydrochlorothiazide doesn’t cause drowsiness.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
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hydrochlorothiazide May Interact with Other Medications

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Hydrochlorothiazide can interact with other medications, herbs, or vitamins you might be taking. That’s why your doctor should manage all of your medications carefully. If you’re curious about how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Note: You can reduce your chances of drug interactions by having all of your prescriptions filled at the same pharmacy. That way, a pharmacist can check for possible drug interactions.

Alcohol interaction

Alcohol and hydrochlorothiazide have an additive effect when taken together. You might feel dizzy after standing up from sitting or lying down because your blood pressure might be too low.

Medications that might interact with this drug

Barbiturates

These drugs have an additive effect when taken together. You might feel dizzy after standing up from sitting or lying down because your blood pressure might be too low.

These drugs include:

  • phenobarbital
  • primidone
  • pentobarbital

Bipolar disorder drugs

In general, these drugs shouldn’t be taken together. Hydrochlorothiazide reduces the clearance of lithium from your body. This increases your risk of lithium toxicity.

These drugs include:

  • lithium

Blood pressure drugs

If you take hydrochlorothiazide with other blood pressure medications there can be an additive effect. This means that your blood pressure may drop too low.

These drugs include:

  • angiotensin-converting enzyme (ACE) inhibitors, such as:
    • lisinopril
    • fosinopril
    • enalapril
  • angiotensin receptor blockers (ARBs), such as:
    • losartan
    • valsartan
    • candesartan
  • beta-blockers, such as:
    • atenolol
    • metoprolol
    • bisoprolol
  • calcium channel blockers, such as:
    • amlodipine
    • verapamil
    • diltiazem

Cholesterol drugs

These drugs may decrease the effectiveness of hydrochlorothiazide. This means that it may not work as well to treat your blood pressure or swelling.

These drugs include:

  • cholestyramine
  • colestipol

Corticosteroids

Taking these drugs together can cause further electrolyte loss (especially potassium). This can lead to medical problems.

These drugs include:

  • prednisone
  • methylprednisolone

Diabetes drugs

If you take hydrochlorothiazide with diabetes drugs, your doctor may increase your dose of your diabetes medications. Hydrochlorothiazide can cause high blood sugar levels.

These drugs include:

  • insulin
  • oral diabetes drugs, such as:
    • exenatide
    • metformin
    • glimepiride
    • pioglitazone
    • sitagliptin

Narcotics

These drugs have an additive effect when taken together. You might feel dizzy after standing up from sitting or lying down because your blood pressure might be too low.

These drugs include:

  • morphine
  • codeine

Pain drugs

Certain pain drugs can reduce the effectiveness of hydrochlorothiazide. This means that it may not work as well to treat your blood pressure or swelling. If you’re taking both of these drugs at the same time, your doctor will closely monitor you.

These drugs include:

  • nonsteroidal anti-inflammatory drugs (NSAIDs), such as:
  • ibuprofen
  • naproxen

Skeletal muscle relaxants

Taking these drugs together may increase the effects of the muscle relaxants. This could lead to more side effects.

These drugs include:

  • tubocurarine

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Hydrochlorothiazide warnings
kidney problems
People with kidney problems

Use caution when taking hydrochlorothiazide if you have poor kidney function. This drug is cleared from your body by your kidneys. If your kidneys don’t work as well, this drug may build up in your body and cause more side effects. If your kidney function gets worse, your doctor might take you off of this medication.

kidneys that do not make urine
People with kidneys that don’t make enough urine

You can’t take hydrochlorothiazide if your kidneys can’t make enough urine. This drug can cause electrolyte and fluid loss, which may make you produce even less urine.

poor liver function
People with poor liver function

Use this drug with caution if you have poor liver function or progressive liver disease. Hydrochlorothiazide can cause electrolyte and fluid imbalance. This can make your liver function worse. 

lupus
People with lupus

This drug can cause your lupus to flare up.

pregnant women
Pregnant women

Hydrochlorothiazide is a category B pregnancy drug. That means two things:

  1. Research in animals hasn’t shown a risk to the fetus when the mother takes the drug.
  2. There aren’t enough studies done in humans to show if the drug poses a risk to the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. Animal studies don’t always predict the way humans would respond. Therefore, this drug should only be used in pregnancy if clearly needed.

breastfeeding
Women who are breast-feeding

Hydrochlorothiazide may pass into breast milk and may cause side effects in a child who is breast-fed.

Talk to your doctor if you breast-feed your baby. You may need to decide whether to stop breast-feeding or stop taking this medication.

for seniors
For seniors

Older adults may process drugs more slowly. A normal adult dose may cause levels of this drug to be higher than normal in your body. If you’re a senior, you may need a lower dose or a different schedule.

allergies
Allergies

Hydrochlorothiazide can cause a severe allergic reaction. Symptoms include:

  • trouble breathing
  • swelling of your throat or tongue
  • hives

If you’re allergic to medications that contain sulfonamide, you shouldn’t take hydrochlorothiazide.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

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How to Take hydrochlorothiazide (Dosage)

Oral tablet

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Hypertension

Brand: Microzide

Form: Oral tablet
Strengths: 12.5 mg, 25 mg, and 50 mg

Generic: hydrochlorothiazide

Form: Oral tablet
Strengths: 12.5 mg, 25 mg, and 50 mg
Adult dosage (ages 18–64 years)
  • The starting dose is 25 mg taken by mouth once per day.
  • Your doctor may increase your dose to 50 mg per day if your blood pressure stays high.
Child dosage (ages 12–17 years)
  • The starting dose is 25 mg taken by mouth once per day.
  • Your doctor may increase your dose to 50 mg per day if your blood pressure stays high.
Child dosage (ages 3–11 years)

The usual dose is 0.5–1 mg per pound per day taken in a single or two divided doses. The dose per day shouldn’t be more than 100 mg.

Child dosage (ages 6 months–2 years)

The usual dose is 0.5–1 mg per pound per day taken in a single or two divided doses. The dose per day shouldn’t be more than 37.5 mg.

Child dosage (ages 0–6 months)

Doses up to 1.5 mg per pound per day taken by mouth in two divided doses.

Senior dosage (ages 65 years and older)

There are no specific recommendations for senior dosing. Older adults may process drugs more slowly. A normal adult dose may cause levels of this drug to be higher than normal in your body. If you’re a senior, you may need a lower dose or a different schedule.

Edema

Brand: Microzide

Form: Oral tablet
Strengths: 12.5 mg, 25 mg, and 50 mg

Generic: hydrochlorothiazide

Form: Oral tablet
Strengths: 12.5 mg, 25 mg, and 50 mg
Adult dosage (ages 18–64 years)
  • The usual dose is 25–100 mg taken by mouth each day as a single or divided dose.
  • Many people respond to intermittent therapy. This means that you may need to take this drug every other day or for 3–5 days each week.
  • Taking hydrochlorothiazide intermittently may reduce your risk of an electrolyte imbalance.
Child dosage (ages 12–17 years)
  • The usual dose is 25–100 mg taken by mouth each day as a single or divided dose.
  • Many people respond to intermittent therapy. This means that you may need to take this drug every other day or for 3–5 days each week.
  • Taking hydrochlorothiazide intermittently may reduce your risk of an electrolyte imbalance.
Child dosage (ages 3–11 years)

The usual dose is 0.5–1 mg per pound per day taken in a single or two divided doses. The dose per day shouldn’t be more than 100 mg.

Child dosage (ages 6 months–2 years)

The usual dose is 0.5–1 mg per pound per day taken in a single or two divided doses. The dose per day shouldn’t be more than 37.5 mg.

Child dosage (ages 0–6 months)

Doses up to 1.5 mg per pound per day taken by mouth in two divided doses.

Senior dosage (ages 65 years and older)

There are no specific recommendations for senior dosing. Older adults may process drugs more slowly. A normal adult dose may cause levels of this drug to be higher than normal in your body. If you’re a senior, you may need a lower dose or a different schedule.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Hydrochlorothiazide comes with serious risks if you don't take it as prescribed.

If you don't take it at all

Your swelling and high blood pressure might get worse. High blood pressure can increase your chance for heart attack or stroke.

If you stop taking it suddenly

Your swelling can increase and your blood pressure might increase rapidly. High blood pressure can increase your chance for heart attack or stroke.

If you don't take it on schedule

Your swelling can increase and your blood pressure might rise. High blood pressure can increase your chance for heart attack or stroke.

If you take too much

If you take too much hydrochlorothiazide, your blood pressure might drop too low. You might feel faint or dizzy.

If you think you’ve taken too much of the drug, act right away. Call your doctor or local Poison Control Center, or go to the nearest emergency room.

What to do if you miss a dose

If you forget to take your dose, take it as soon as you remember. If it’s just a few hours until the time for your next dose, then wait and only take one dose at that time.

Never try to catch up by taking two doses at once. This could result in toxic side effects.

How to tell if the drug is working

If this drug is working, your blood pressure will be lower or the swelling in your legs and feet may get better. Your doctor will monitor your blood pressure at your checkups. You can also check your blood pressure at home. Keep a log with the date, time of day, and your blood pressure readings. Bring this diary with you to your doctor appointments.

Hydrochlorothiazide is used for long-term treatment.

Take hydrochlorothiazide in the morning

This drug may make you urinate more. Don’t take it in the evening so that you don’t get up to use the bathroom at night.

Store hydrochlorothiazide from 68–77°F (20–25°C)

Keep this drug away from light and high temperature.

Keep your drugs away from areas where they could get wet, such as bathrooms. Store this drug away from moisture and damp locations.

Travel

When traveling with your medication:

  • Always carry your medication with you, such as in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Self-management

You may need to check your blood pressure at home. You should keep a log with the date, time of day, and your blood pressure readings. Bring this diary with you to your checkups.

Clinical monitoring

During treatment with this drug, your doctor may check your potassium levels to make sure that you don’t have any imbalances.

The generic is usually stocked in the pharmacy

The brand name might not be stocked at every pharmacy, so call ahead when refilling your prescription.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be more suitable for you than others. Talk to your doctor about possible alternatives.

What does the pill look like?

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How Much Does hydrochlorothiazide Cost?

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We've partnered with GoodRx so you can compare prices, find discounts and save up to 80% on your next prescription. Check out the low coupon prices below — no insurance required.

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Lowest price for hydrochlorothiazide

Walmart $4.00
Kroger Pharmacy $4.00
Kmart $6.12
These prices represent the lowest priced national pharmacies for hydrochlorothiazide on GoodRx. They may be lower than your insurance.

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These prices represent the lowest priced national pharmacies for hydrochlorothiazide on GoodRx. They may be lower than your insurance.

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Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on September 24, 2015

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
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