Hydrochlorothiazide (Oral)

Hydrochlorothiazide is used to treat edema and high blood pressure in children and adults.


Hydrochlorothiazide is an antihypertensive medication that may be prescribed in conjunction with other drugs to keep high blood pressure levels under control.

Untreated high blood pressure causes the heart to work overtime and consequently places patients at an increased risk of a heart attack or stroke.

Hydrochlorothiazide is available by prescription only and features other applications. It is sometimes prescribed for fluid retention due to other underlying ailments.

It is sold under several U.S. trade names, including:

  • Aquazide
  • Microzide
  • Zide
  • Hydrocot

Pharmacists dispense this medicine in a number of forms, including as a capsule, tablet, or syrup.

Mechanisms of Action

As a diuretic, Hydrochlorothiazide helps to speed up salt and water removal from the body. As a result, it is effective for the treatment of edema caused by kidney or liver disease.

It is also beneficial for lowering blood pressure levels because it reduces sodium reabsorption rates in the bloodstream.

Other Important Notes

  • Use as a Diuretic' Though Hydrochlorothiazide is considered a water pill, it is not generally considered a first-choice diuretic due to more effective hybrids available on the marketplace. It is, however, a preferred choice for hypertension.
  • Use for Kidney Stones Hydrochlorothiazide is also used for the treatment of kidney stones in some cases. It lowers calcium output from the kidneys and subsequently decreases the chances of patients developing kidney stones.
  • Other Applications 'Hydrochlorothiazide is also effective for the treatment of diabetes insipidus and certain types of acidosis.

Due to its effectiveness in treating multiple conditions, Hydrochlorothiazide has earned a spot on the List of Essential Medicines published by the World Health Organization.

Conditions Treated?

  • Hypertension, Edema

Type Of Medicine?

  • Antihypertensive, Thiazide Diuretic

Side Effects

Patients who take Hydrochlorothiazide by mouth may experience several side effects, ranging from mild or severe. Most subside with time. Nevertheless, if your symptoms persist or it becomes difficult to maintain a daily routine, do not hesitate to contact your healthcare provider.

Some of the most common side effects associated with Hydrochlorothiazide are:

  • Pain in the stomach
  • Changes in stool color
  • Gum bleeding
  • Skin irritation
  • Feeling bloated
  • Bloody stools or urine
  • Lips or nails that appear blue
  • Fevers, chills, or cold sweats
  • Feeling confused
  • Pain the chest
  • Numbing or tingling sensation
  • Frequent constipation
  • Sounding hoarse
  • Coughing up blood or substances that look pink and frothy
  • Confusion
  • Lower outputs of urine
  • Labored breathing
  • Wheezing
  • Trouble swallowing
  • An abnormal heartbeat
  • Feeling faint, dizzy, or lightheaded
  • Dehydration
  • Parched lips or mouth
  • Fruity or bad smelling breath
  • Puffiness
  • Feeling sick
  • Lethargy
  • A headache
  • Hives and rashes
  • Extreme cravings or thirstiness
  • Heartburn
  • Itchiness
  • Pain or cramps in the muscles or joints
  • Heat loss or feeling cold
  • Bleeding from the nose
  • Eye redness and pain
  • Skin discolorations, including lesions or purple or red marks
  • Convulsions
  • Feeling nervous
  • Skin that easily bleeds or bruises
  • Extreme drowsiness or tiredness
  • Jaundice
  • Sudden weight gain
  • Low sex drive
  • Constant moving sensation
  • Balding
  • Feeling restless

When to Call a Doctor

If you develop severe reactions when using this drug, seek medical help right away. Some examples of a medical emergency are:

An Allergic Reaction

You may develop a serious and potentially fatal allergy to Hydrochlorothiazide. Some of the warning signs that medical help is required are if you experience:

  • Hives
  • Rashes
  • Puffiness
  • Trouble breathing
  • Difficulty swallowing

Skin Sensitivities

If you develop a painful rash that is accompanied by a fever or cracks, peels, or blistering skin, this could be a sign of Stevens-Johnson syndrome, which requires immediate medical intervention. If you experience these symptoms, do not wait until your symptoms subside. Call 911 or your primary care provider immediately.

Kidney Failure

One of the rare side effects of Hydrochlorothiazide is kidney failure. Some of the telltale signs of this condition are:

  • Lethargy
  • Difficulty breathing
  • Feeling confused
  • Lower urinary output
  • Swelling of the lower body
  • Blurriness and/or pain in the eyes


Medical providers understand that every patient is different. Before prescribing Hydrochlorothiazide for the treatment of high blood pressure or edema, the following factors are carefully considered:

  • The patient's age and weight
  • The brand name of hydrochlorothiazide
  • The medication strength and formula
  • The length of treatment
  • The number of times per day needed

Note: The following table reflects average doses and should not take the place of the instructions dispensed by your pharmacy

Hydrochlorothiazide Capsule Doses for High Blood Pressure

  • Children: Based on a Doctor's Discretion
  • Adults: 12.5 mg | 1X Daily (Max Daily Dose: 50 mg)

Hydrochlorothiazide Tablet Doses for High Blood Pressure

  • Children: Based on a Doctor's Discretion
  • Adults: 25 mg | Divided 1-2X Daily

Note: These are preliminary dosage amounts. Your doctor may lower or increase this prescription based on tolerance and response rates to the medicine.

Hydrochlorothiazide Doses for Edema

  • Children: Based on Weight
  • Adults: 25-100 mg | Divided 1-2X Daily

Taking the Hydrochlorothiazide Syrup

If you were prescribed a Hydrochlorothiazide syrup, be sure to shake the bottle thoroughly before each use to ensure the medicine is evenly distributed. Additionally, use the dispensing cup to accurately measure the prescribed dose amount. Household spoons are not recommended for medicinal use.

How to Handle a Missed Dose

If you miss a dose of Hydrochlorothiazide, never double the prescription. You can take it as soon as you remember, so long as the time is not drawing close for the next scheduled dose.

If you accidentally swallowed too much of this medicine, contact 911 immediately. The American Association of Poison Control Centers is also available by calling 1(800) 222-1222.

Drug Interactions

Extra care should be taken by medical providers when prescribing Hydrochlorothiazide concomitantly with the following medications, as negative interactions are known to occur:

  • Ketoprofen
  • Piketoprofen
  • Flurbiprofen
  • Choline Salicylate
  • Diflunisal
  • Acemetacin
  • Feprazone
  • Proquazone
  • Meloxicam
  • Lithium
  • Bepridil
  • Dexketoprofen
  • Dofetilide
  • Indomethacin
  • Metildigoxin
  • Valdecoxib
  • Oxaprozin
  • Etoricoxib
  • Gossypol
  • Levomethadyl
  • Carbamazepine
  • Droperidol
  • Diclofenac
  • Tolfenamic Acid
  • Digoxin
  • Dexibuprofen
  • Lumiracoxib
  • Deslanoside
  • Sulindac
  • Etofenamate
  • Dipyrone
  • Morniflumate
  • Salsalate
  • Loxoprofen
  • Tenoxicam
  • Amphetamine
  • Parecoxib
  • Rofecoxib
  • Tolmetin
  • Amtolmetin Guacil
  • Ketorolac
  • Niflumic Acid
  • Etodolac
  • Fepradinol
  • Aceclofenac
  • Methotrexate
  • Sodium Salicylate
  • Nimesulide
  • Nimesulide Beta-Cyclodextrin
  • Felbinac
  • Cholestyramine
  • Fenoprofen
  • Arsenic Trioxide
  • Proscillaridin
  • Mefenamic Acid
  • Flufenamic Acid
  • Phenylbutazone
  • Digitalis
  • Piroxicam
  • Ouabain
  • Digitoxin
  • Celecoxib
  • Acetyldigoxin
  • Droxicam
  • Nabumetone
  • Nepafenac
  • Clonixin
  • Oxyphenbutazone
  • Cyclophosphamide
  • Ginkgo
  • Flecainide
  • Naproxen
  • Meclofenamate
  • Licorice
  • Topiramate
  • Tiaprofenic Acid
  • Bromfenac
  • Ibuprofen
  • Sotalol
  • Aspirin
  • Bufexamac
  • Proglumetacin
  • Lornoxicam
  • Ketanserin
  • Salicylic Acid
  • Floctafenine
  • Propyphenazone

In the event that both medicines are required, the dosage amounts for each are generally modified.

Interactions With Alcohol

Alcohol should be consumed in moderation when undergoing treatment with Hydrochlorothiazide. Concurrent use may cause extreme dizziness and may also cause patients to feel less alert.

Interactions With Tobacco

Smoking may affect how this medication works and moreover increase high blood pressure. Ask your doctor about suggestions on what smoking aids may be used.

Interactions with Pre-Existing Medical Conditions

Patients with underlying conditions should discuss these before commencing treatment with Hydrochlorothiazide. This medicine may exacerbate certain medical problems, including:

  • Hypersensitivities to sulfa
  • Diabetes
  • Asthma
  • Imbalances of electrolyte
  • Gout
  • High cholesterol
  • High levels of uric acid
  • Low blood sugar
  • Liver disorders
  • Kidney disease
  • Lupus

To be on the safe sideĀ ' and to lower the risk of negative interactions, create a list of all the current medicines you take, including prescription and over the counter drugs like vitamins and herbal supplements.

Additionally, tell your doctor about your full medical history, including any pre-existing conditions or adverse reactions to medications, foods, dyes, or animal products.

With this information, your medical provider is better able to assess the best antihypertensive for keeping your high blood pressure levels under control.


Patients are advised to read all instructions provided by a pharmacist and the insert label included with this medicine. Some of the most common precautions include:

Keep All Follow-Up Appointments

To verify that your high blood pressure levels have stabilized with Hydrochlorothiazide, your doctor will set up a series of follow-up visits. Ensure these appointments are met to determine if additional interventions are needed. Patients can expect to complete urine or blood tests at follow-up visits. These exams are performed to check for adverse side effects to the drug.

Proper Use

Never share this medicine with other members of your household, even if they have been diagnosed with high blood pressure. A personalized consultation and prescription are required for each patient to reduce the side effects of Hydrochlorothiazide.

Risk of Hypokalemia

One of the side effects of taking Hydrochlorothiazide is the possibility of potassium depletion. Our bodies require this key mineral for several functions. It's one of the main reasons your doctor will tell you to eat a potassium-rich diet when undergoing treatment with Hydrochlorothiazide.

Potassium Rich Foods

Some examples of potassium-rich foods you can try are:

  • Bananas
  • Oranges
  • Prunes
  • Raisins

Additionally, your doctor may prescribe a potassium supplement to stop a deficiency from the get-go.

If a potassium deficiency occurs, medical intervention is required. Call your doctor immediately if you notice the following symptoms of a potassium loss, which is otherwise known as Hypokalemia:

  • Seizures
  • Lower outputs of urine
  • Extreme sleepiness
  • Dehydration accompanied by parched lips
  • Extreme thirst
  • An abnormal heartbeat or pulse
  • Pain in the muscles
  • Cramping
  • Feeling nauseous
  • Lethargy

Vision Changes

Be sure to keep all referrals to an ophthalmologist and moreover consult a healthcare provider if you are experiencing any of the following side effects of Hydrochlorothiazide:

  • Blurriness
  • Trouble reading
  • Pain in the eyes
  • Any new or sudden vision changes

Dizziness and Fainting

While using Hydrochlorothiazide, you may feel dizzy. If you feel lightheaded when using this medicine, stop all activities that require you to be alert and call for help. For example, if you feel dizzy while driving or operating heavy machinery, stop and call for help.

Your doctor will also advise that you limit alcohol intake, as this will exacerbate feelings of dizziness.

Get Up Slowly

Patients often report feeling dizzy or faint upon getting up after sitting or lying down. To reduce this side effect, doctors suggest getting up slowly.

When you wake up in the mornings, let your feet hang off the side of the bed and let them rest for a while before standing up.

If you regularly feel faint, inform other members of your household or co-workers about the possibility of syncope and create a plan of action on how to proceed.

As an extra precaution, patients who take Hydrochlorothiazide should always wear a medical I.D. bracelet to help keep EMTs in the loop on their full medical history.

In life-and-death scenarios, medical I.D. bracelets eliminate the guesswork and are vital for helping medical workers to act fast and accurately.


Hydrochlorothiazide may cause a serious allergic reaction to occur in certain patients. In addition to hypersensitivities to foods, dyes, or animal products, you should also tell your doctor if you had any past negative reactions to:

  • Hydrochlorothiazide
  • Penicillin
  • Sulfonamide antibiotics

Pre-Scheduled Medical Appointments

Hydrochlorothiazide could influence the results of certain medical tests, including thyroid function exams. Be sure to tell your doctor if you are using this medication before undergoing any new medical or dental assessments.

Over-The-Counter Medicines

Do not use any over-the-counter medicines while taking Hydrochlorothiazide before first consulting with your healthcare provider. Some examples of these OTCs include:

  • Cough or cold medicines
  • Hay fever drugs
  • Sinus treatments
  • Nasal sprays
  • Asthma supplements
  • Weight loss drugs

Use with Cholesterol Medicines

If you are taking a cholesterol medicine concurrently with Hydrochlorothiazide, your pharmacist will normally recommend:

1. Taking the cholesterol medicine one hour before Hydrochlorothiazide, or:
2. Waiting 4 hours after taking Hydrochlorothiazide

As always, check with your doctor first.

Maintaining the Medication Schedules

Healthcare experts warn against discontinuing Hydrochlorothiazide without a doctor's approval.

This medication is not a cure for hypertension, but it effectively works to keep blood pressure levels under control. If you stop using this medicine abruptly and without a doctor's consent, this places you at a higher risk of developing adverse reactions.

Hydrochlorothiazide, along with other antihypertensive drugs, is often prescribed for long-term use and at times for life. If you have questions or concerns while using this medicine, do not hesitate to contact your pharmacist or primary care doctor.

Note: An exception to the rule of abrupt discontinuation would be if you experience serious side effects that are life-threatening. In this event, discontinue use and contact 911 immediately.

Dietary and Lifestyle Changes

To supplement this drug and to help regulate your high blood pressure, your doctor may also suggest dietary and lifestyle changes. Be sure to discuss any new plans with your healthcare provider, because certain activities like vigorous exercise may be counterproductive.

Healthcare providers generally suggest taking a gradual approach to lifestyle changes, building up slowly on any progress you make over time.


A few dietary and lifestyle tips for helping to manage hypertension are:

  • Eating a low-sodium diet
  • Living an active lifestyle
  • Keeping your weight under control
  • Practicing stress-management techniques
  • Incorporating foods that are rich in potassium

Pregnant or Nursing Mothers

Extra precautions must be taken when prescribing Hydrochlorothiazide to pregnant or nursing mothers. Limited information is available regarding the side effects of Hydrochlorothiazide in developing fetuses or newborns. As a result, do not start treatment with this medicine if you are pregnant or breastfeeding.

Additionally, you should tell your doctor immediately if you get pregnant while using this Hydrochlorothiazide.

Sun Exposure

Hydrochlorothiazide may cause your skin to crack, peel, blister, or burn, especially with exposure to sunlight. To reduce this risk, be sure to:

  • Always wear sunscreen outdoors
  • Dress appropriately when heading outside 'wear a hat and lightweight clothing
  • Wear sunglasses as your eyes may be hypersensitive to sunlight when using Hydrochlorothiazide
  • Limit exposure to the sun


This medicine should be stored out of the reach of children and pets. It can be placed at a room temperature of 15 C to 30 C (59 F to 86 F), regardless of whether you were prescribed tablets, capsules, or a syrup.

To preserve the quality and effectiveness of this medicine, do not store in:

  • The freezer
  • Heat
  • Humid temperature
  • Direct lighting
  • Sunlight

Other Tips:

  • Reseal the cap tightly after each use
  • Place in a high area or in a locked cabinet

If your doctor has informed you to stop using this medicine, consider returning any unused portions of Hydrochlorothiazide to a local pharmacy. Most local drugstores feature a take-back program to help stop substance abuse and moreover keep drugs out of the natural ecosystem.


Hydrochlorothiazide is a standalone or supplementary treatment for high blood pressure. It is available by prescription only and is generally sold under the drug name Aquazide-H, though other brand names exist.

If you have fluid retention, kidney stones, or acidosis, your doctor may also prescribe Hydrochlorothiazide.

Hydrochlorothiazide is available as a capsule, tablet, or a syrup, each carrying different dosage requirements. Healthcare providers also factor in the patients' full medical history when prescribing this medicine. On average, Hydrochlorothiazide is given once or twice daily.

If hypertension remains untreated, patients are considered as being at risk of organ failure.

Antihypertensive medications such as Hydrochlorothiazide are used as a preventative measure for regulating hypertension' before serious bodily injury occurs.

A holistic approach is generally considered the best course of treatment for high blood pressure. As a result, your doctor may also outline dietary or lifestyle changes that are proven to keep high blood pressure under control. These include eating foods that are low in fat or salt content and exercising regularly. Patients are also advised to limit alcohol intake and stop smoking as these activities typically elevate blood pressure levels. Before subscribing to a new diet or exercise plan, however, consult your healthcare provider.

As with all medications, Hydrochlorothiazide may cause unwanted side effects to occur, including but not limited to dizziness, constipation, lethargy, drowsiness, and more. For these reasons, doctors advise that patients create a plan for how to react to negative side effects. If you feel dizzy, for example, you should delegate driving and other high-risk activities to someone else.

Patients should note that Hydrochlorothiazide is not a cure for hypertension. However, it is widely used as the first line of treatment for regulating high blood pressure for the long term. In some cases, Hydrochlorothiazide may be prescribed for life.

Patients taking Hydrochlorothiazide ultimately benefit from being at a reduced risk of heart attacks, strokes, and other serious side effects of uncontrolled hypertension.

Be sure to follow all instructions provided by your healthcare provider, including taking this medicine exactly as prescribed for as long as it is required.