What is chlorothiazide?

DIURIL ® (chlorothiazide) is a diuretic and antihypertensive. It is 6-chloro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. Its empirical formula is C 7 H 6 CIN 3 O 4 S 2 and its structural formula is: It is a white, or practically white, crystalline powder with a molecular weight of 295.72, which is very slightly soluble in water, but readily soluble in dilute aqueous sodium hydroxide. It is soluble in urine to the extent of about 150 mg per 100 mL at pH 7. DIURIL Oral Suspension contains 250 mg of chlorothiazide per 5 mL, alcohol 0.4%, with methylparaben 0.1%, propylparaben 0.02%, and benzoic acid 0.1% added as preservatives. The inactive ingredients are D&C Yellow 10, flavors, glycerin, purified water, sodium saccharin, sucrose and tragacanth. Chemical Structure

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.

Has chlorothiazide been recalled?

The FDA's Enforcement database lists 4 recall records whose product description mentions chlorothiazide. The most recent: Bisoprolol Fumarate and Hydrochlorothiazide tablets (Jan 21, 2026). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.

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) sourcesHow we research

Key facts

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

How chlorothiazide 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 ).

Chlorothiazide 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…

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
#	Drug	Rating	Type	Form	Generic?	Typical price
1	Chlorothiazide	Not yet rated	Prescription	Injectable	—	—	View →
2	Diuril	Not yet rated	Prescription	Suspension	—	—	View →

What chlorothiazide pills look like

Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.

Chlorothiazide pill imprints
Imprint	Strength	Colour	Shape	Maker
U;128	25 mg	orange	round	—
T4	5 mg / 12.5 mg	white	oval	—
T;3	10 mg / 25 mg	pink	oval	—
VASE;10;25	10 mg / 25 mg	red	oval	—
C133	5 mg / 12.5 mg	white	round	—
C134	10 mg / 25 mg

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.

Chlorothiazide recalls

From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.

Frequently asked questions

What is chlorothiazide?: DIURIL ® (chlorothiazide) is a diuretic and antihypertensive. It is 6-chloro-2 H -1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. Its empirical formula is C 7 H 6 CIN 3 O 4 S 2 and its structural formula is: It is a white, or practically white, crystalline powder with a molecular weight of 295.72, which is very slightly soluble in water, but readily soluble in dilute aqueous sodium hydroxide. It is soluble in urine to the extent of about 150 mg per 100 mL at pH 7. DIURIL Oral Suspension contains 250 mg of chlorothiazide per 5 mL, alcohol 0.4%, with methylparaben 0.1%, propylparaben 0.02%, and benzoic acid 0.1% added as preservatives. The inactive ingredients are D&C Yellow 10, flavors, glycerin, purified water, sodium saccharin, sucrose and tragacanth. Chemical Structure
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.

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.