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What is hydrochlorothiazide?
Hydrochlorothiazide is a thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention. Hydrochlorothiazide treats fluid retention (edema) in people with congestive heart failure, cirrhosis of the liver, or kidney disorders, or edema caused by taking steroids or estrogen. This medication is also used to treat high blood pressure (hypertension). Hydrochlorothiazide may also be used for other purposes not listed in this medication guide.

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What is the price of this medication and similar alternatives?

Pricing information provided by drugstore.com.

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What are the possible side effects of hydrochlorothiazide?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using this medication and call your doctor at once if you have a serious side effect such as:

• dry mouth, thirst, nausea, vomiting;

• feeling weak, drowsy, restless, or light-headed;

• fast or uneven heartbeat;

• muscle pain or weakness;

• numbness or tingly feeling;

• a red, blistering, peeling skin rash; or

• nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

• diarrhea;

• mild stomach pain;

• constipation; or

• blurred vision.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

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How should I take hydrochlorothiazide?
Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results from this medication. To be sure this medication is not causing harmful effects, your blood pressure will need to be checked on a regular basis. Do not miss any scheduled appointments. Your blood and urine may both be tested if you have been vomiting or are dehydrated.

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What is the most important information I should know about hydrochlorothiazide?
Do not use this medication if you are allergic to hydrochlorothiazide or if you are unable to urinate. Before using this medication, tell your doctor if you have liver disease, kidney disease, asthma or allergies, gout, diabetes, or if you are allergic to sulfa drugs. Avoid drinking alcohol, which can increase some of the side effects of hydrochlorothiazide. Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

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What happens if I miss a dose?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

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What other drugs will affect hydrochlorothiazide?
Before taking this medication, tell your doctor if you are using any of the following drugs: lithium; digoxin (Lanoxin); cholestyramine (Prevalite, Questran) or colestipol (Colestid); steroids (prednisone and others); other blood pressure medications; NSAIDs (non-steroidal anti-inflammatory drugs) such as aspirin, ibuprofen (Motrin, Advil), diclofenac (Voltaren), indomethacin, naproxen (Aleve, Naprosyn), piroxicam (Feldene), nabumetone (Relafen), etodolac (Lodine), and others; or insulin or diabetes medicine taken by mouth.

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Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?

Hydrochlorothiazide has been assigned to pregnancy category B by the FDA. Animal studies have failed to reveal evidence of fetal harm. There are no data from controlled human studies, but retrospective reviews have shown an increased risk of malformations associated with thiazide diuretics. The drug should be used during pregnancy only if clearly needed.

The Collaborative Perinatal Project monitored 50,282 mother-child pairs, of whom 233 were exposed to thiazide or related diuretics during the first trimester. An increased risk of malformations was found for thiazide diuretics. Use of thiazides after the first trimester does not seem to carry this risk. Thiazide diuretics may, however pose metabolic risks to the mother and fetus (hyponatremia, hypokalemia, thrombocytopenia, hyperglycemia), and may have a direct effect on smooth muscle, resulting in inhibition of labor. Data from the Michigan Medicaid Birth Defects Study has revealed an association between the use of hydrochlorothiazide (HCTZ) and congenital abnormalities (written communication, Franz Rosa, MD, Food and Drug Administration, 1994). This was a retrospective study of 229,101 completed pregnancies between 1985 and 1992, of which 567 were exposed to HCTZ at some time during the first trimester, and 1,173 were exposed to the drug at any time during pregnancy. Of the 567 pregnancies, there were 24 total and 7 cardiovascular birth defects (22 and 6 were expected, respectively). There were no observations of cleft palate, spina bifida, limb reduction, or hypospadias. The one instance of polydactyly did not achieve statistical significance. These data are consistent with an association between the use of HCTZ and birth defects, although other factors, including underlying disease(s) of the mother are not accounted for. Cases of neonatal thrombocytopenia associated with antepartum administration of thiazide diuretics have been reported.

Hydrochlorothiazide (HCTZ) is secreted into human milk in low concentrations. Adverse effects in the nursing infant are unlikely. HCTZ is considered compatible with breast-feeding by the American Academy of Pediatrics; however, the manufacturer recommends that due to the potential for serious adverse reactions in nursing infants, a decision should be made to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

In one case, a peak milk HCTZ concentration of 125 ng/mL was measured between 4 and 12 hours after a (usual daily) dose of HCTZ 50 mg in one subject. A simultaneously measured maternal serum HCTZ level was approximately 275 ng/mL. There were no detectable drug levels or electrolyte abnormalities in the baby's blood. The authors calculated that, if a 1-month-old infant takes approximately 600 mL of milk per day, and the average milk HCTZ level is approximately 80 ng/mL, the infant would be exposed to approximately 0.05 mg HCTZ a day. This usually represents an insignificant amount of HCTZ to the infant as adverse effects in the nursing infant are unlikely.

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Who should NOT use this medication?

• Anuria.
• Known hypersensitivity to hydrochlorothiazide, other thiazides, or any ingredient in the formulation.
• Although manufacturers state allergy to other sulfonamide derivatives is a contraindication, evidence to support cross-sensitivity is limited, and history of sensitivity to sulfonamide anti-infectives (“sulfa sensitivity”) should not be considered an absolute contraindication.

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What happens if I overdose?
Seek emergency medical attention if you think you have used too much of this medicine. Overdose symptoms may include nausea, weakness, dizziness, dry mouth, thirst, and muscle pain or weakness.

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What should I discuss with my doctor before taking hydrochlorothiazide?
Do not use this medication if you are allergic to hydrochlorothiazide, or if you are unable to urinate. Before using hydrochlorothiazide, tell your doctor if you have: kidney disease; liver disease; asthma or allergies; gout; diabetes; or an allergy to sulfa drugs. If you have any of these conditions, you may need a dose adjustment or special tests to safely take hydrochlorothiazide. FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

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Can I stop taking the medication if I feel better?
Even though you may feel better you should not stop taking your high blood pressure medication without first checking with your healthcare provider.

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I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.

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Where can I get more information?
More Information

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