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Chlorothiazide: uses, dosing, side effects & brands

Chlorothiazide is a thiazide diuretic sold in the U.S. under 2 brand and generic names, for edema, glomerulonephritis and heart failure. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.

By the pharmaranks editorial teamReviewed against the FDA (openFDA label, NDC Directory & Enforcement) sourcesUpdated Jul 24, 2026How we research

Key facts

Drug class
Thiazide Diuretic
Treats (across its forms)
Edema, Glomerulonephritis and Heart Failure
Available as
Injectable · Suspension
Sold as
2 products — Chlorothiazide and Diuril
Prescription?
Prescription only
Generic available?
Yes

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How Diuril is dosed

From the FDA label for Diuril (application NDA011870). Other chlorothiazide products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.

Therapy should be individualized according to patient response. Use the smallest dosage necessary to achieve the required response. Adults For Edema The usual adult dosage is 500 mg to 1,000 mg (10 mL to 20 mL) once or twice a day. Many patients with edema respond to intermittent therapy, i.e., administration on alternate days or on three to five days each week. With an intermittent schedule, excessive response and the resulting undesirable electrolyte imbalance are less likely to occur. For Control of Hypertension The usual adult starting dosage is 500 mg or 1,000 mg (10 mL to 20 mL) a day as a single or divided dose. Dosage is increased or decreased according to blood pressure response. Rarely some patients may require up to 2,000 mg (40 mL) a day in divided doses. Infants and Children For Diuresis and For Control of Hypertension The usual pediatric dosage is 5 mg to 10 mg per pound (10 mg/kg to 20 mg/kg) per day in single or two divided doses, not to exceed 375 mg per day (2.5 mL to 7.5 mL or ½ to 1½ teaspoonfuls of the oral suspension daily) in infants up to 2 years of age or 1,000 mg per day in children 2 to 12 years of age. In infants less than 6 months of age, doses up to 15 mg per pound (30 mg/kg) per day in two divided doses may be required (see PRECAUTIONS , Pediatric Use ).

Everything below is the FDA label for Diuril (suspension). Chlorothiazide is also sold as injectable, and those are different medicines to take — follow the label for the one you were prescribed.

Diuril side effects

The following adverse reactions have been reported and, within each category, are listed in order of decreasing severity: Body as a Whole: Weakness. Cardiovascular: Hypotension, including orthostatic hypotension (may be aggravated by alcohol, barbiturates, narcotics or antihypertensive drugs). Digestive: Pancreatitis, jaundice (intrahepatic cholestatic jaundice), diarrhea, vomiting, sialadenitis, cramping, constipation, gastric irritation, nausea, anorexia. Hematologic: Aplastic anemia, agranulocytosis, leukopenia, hemolytic anemia, thrombocytopenia. Hypersensitivity: Anaphylactic reactions, necrotizing angiitis (vasculitis and cutaneous vasculitis), respiratory distress including pneumonitis and pulmonary edema, photosensitivity, fever, urticaria, rash, purpura. Metabolic: Electrolyte imbalance (see PRECAUTIONS ), hyperglycemia, glycosuria, hyperuricemia. Musculoskeletal: Muscle spasm. Nervous System/Psychiatric: Vertigo, paresthesias, dizziness, headache, restlessness. Renal: Renal failure, renal dysfunction, interstitial nephritis (see WARNINGS ). Skin: Erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis, alopecia. Special Senses: Transient blurred vision, xanthopsia. Urogenital: Impotence. Whenever adverse reactions are moderate or severe, thiazide dosage should be reduced or therapy withdrawn. To report…

Who shouldn’t take Diuril

Anuria. Hypersensitivity to this product or to other sulfonamide-derived drugs.

Diuril drug interactions

When given concurrently the following drugs may interact with thiazide diuretics. Alcohol, Barbiturates, or Narcotics - potentiation of orthostatic hypotension may occur. Antidiabetic Drugs (Oral Agents and Insulin) - dosage adjustment of the antidiabetic drug may be required. Other Antihypertensive Drugs - additive effect or potentiation. Cholestyramine and Colestipol Resins - Both cholestyramine and colestipol resins have the potential of binding thiazide diuretics and reducing diuretic absorption from the gastrointestinal tract. Corticosteroids, ACTH - intensified electrolyte depletion, particularly hypokalemia. Pressor Amines (e.g., Norepinephrine) - possible decreased response to pressor amines but not sufficient to preclude their use. Skeletal Muscle Relaxants, Nondepolarizing (e.g., Tubocurarine) - possible increased responsiveness to the muscle relaxant. Lithium - generally should not be given with diuretics. Diuretic agents reduce the renal clearance of lithium and add a high risk of lithium toxicity. Refer to the package insert for lithium preparations before use of such preparations with DIURIL. Non-steroidal Anti-inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 (COX-2) Inhibitors - In some patients, the administration of a non-steroidal anti-inflammatory agent including a selective COX-2 inhibitor can reduce the diuretic, natriuretic, and antihypertensive effects of loop, potassium-sparing and thiazide diuretics. Therefore, when DIURIL and non-steroidal anti-inflammatory agents or selective COX-2 inhibitors are used concomitantly, the patient should be observed closely to determine if the desired effect of the diuretic is obtained. In some patients with compromised renal function (e.g., elderly patients or patients who are volume-depleted, including those on diuretic therapy) who are being treated with NSAIDs, including selective COX-2 inhibitors, the co-administration of angiotensin II receptor antagonists or ACE inhibitors may result in a further deterioration of renal function, including possible acute renal failure. These effects are usually reversible. These interactions should be considered in patients taking NSAIDs including selective COX-2 inhibitors concomitantly with diuretics and angiotensin II antagonists or ACE inhibitors. Therefore, the combination should be administered with caution, especially in the elderly.

Every chlorothiazide product we track (2)

Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.

Chlorothiazide products
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Combination products containing chlorothiazide

A combination is a different drug — different dosing, different warnings. It is listed here so you can find it, not so you can substitute it.

How long chlorothiazide keeps

No chlorothiazide label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.

Does chlorothiazide expire? The in-use limits and storage rules from its labels

Chlorothiazide and breastfeeding

From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.

Amounts of chlorothiazide in milk are low, but high doses might suppress lactation. Low-dose chlorothiazide appears to be acceptable during lactation. Intense diuresis with large doses may decrease breastmilk production.

Full LactMed record for chlorothiazide: levels in milk, effects in breastfed infants, and the drugs it would consider instead

National Institute of Child Health and Human Development, record revised May 15, 2025. LactMed states its information is not a substitute for professional judgement.

What people report to the FDA about chlorothiazide

The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 1,040 reports naming chlorothiazide, and the FDA flagged 81% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:

  • diarrhoea64 reports
  • dyspnoea64 reports
  • hypotension59 reports
  • pyrexia56 reports
  • respiratory failure45 reports
  • headache44 reports
  • pneumonia42 reports
  • vomiting39 reports

Read these as a signal, not a rate. A report does not mean chlorothiazide caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.

Source: openFDA drug/event (FAERS), retrieved August 25, 2026.

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Frequently asked questions

What is Diuril?

Diuril (Chlorothiazide) is a thiazide diuretic used to treat Edema, Glomerulonephritis, Heart Failure, Hypertension.

What kind of drug is chlorothiazide?

The FDA classifies chlorothiazide as a thiazide diuretic. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

Can you take chlorothiazide with other medicines?

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run chlorothiazide against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

What brand names is chlorothiazide sold under?

We track 2 chlorothiazide-containing products in the U.S.: Chlorothiazide and Diuril. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.

What forms does chlorothiazide come in?

Across the brands we track, chlorothiazide is currently marketed as injectable and suspension, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Is there a generic chlorothiazide?

Yes. Our catalog lists 1 generic chlorothiazide product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.

Cite this page
APA
pharmaranks. (2026, July 24). Chlorothiazide: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/chlorothiazide
MLA
“Chlorothiazide: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/chlorothiazide.

We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.

Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.

Read the full FDA label for chlorothiazide on DailyMed (NIH) ↗.