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Medicine guide

Thalitone

15 mg · Tablet

  • Prescription only
  • Thiazide-like Diuretic
Active substance
Chlorthalidone
Made by
Casper Pharma LLC

Quoted from the official source. Not yet reviewed by Mediclarum — the leaflet in your pack is authoritative.

At a glance

Quoted from the official label · 2026-06-25

What it is

Thiazide-like Diuretic

Used for
  • For the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions (1.1).
The label’s usual adult dose

Recommended initial dose is 15 mg daily with food. If additional blood pressure reduction is needed, increase the dose to 25 mg (2.2).

Recommended initial dose is 50 mg to 100 mg daily or 100 mg on alternate days. Depending on response, dosage can be decreased or increased up to a maximum of 200 mg daily (2.3). 2.1 General Considerations THALITONE cannot be substituted with other formulations of chlorthalidone. Initiate therapy with the lowest possible dose, then titrate according to individual patient response. 2.2 Hypertension The initial recommended dose is 15 mg once daily with food. After 2 weeks, the dosage may be increased to a single daily dose of 25 mg if additional blood pressure reduction is needed. Doses above 25 mg are not expected to result in increased blood pressure reduction. 2.3 Edema The recommended initial dosage is 50 to 100 mg daily or 100 mg on alternate days. Depending on response, dosage can be decreased or increased up to a maximum of 200 mg daily.

Full directions ↓
Do not take it if

THALITONE is contraindicated in patients with anuria or hypersensitivity to chlorthalidone or other sulfonamide-derived drugs.

All warnings ↓
Good to know
  • Prescription only
  • FDA enforcement reports list no ongoing recall, and none from the last two years, for this product code · checked 2026-10-02
61other products contain Chlorthalidone — compare makers, forms and strengths

Every line above is selected, not written, from the official label. Nothing is reworded. DailyMed

What it is for

THALITONE is a thiazide-like diuretic indicated:

  • For the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions (1.1).
  • as adjunctive therapy in edema associated with heart failure, cirrhosis of the liver, and renal disease, including nephrotic syndrome (1.2). 1.1 Hypertension THALITONE ® is indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including the class to which this drug principally belongs. There are no controlled trials demonstrating risk reduction with THALITONE. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than one drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program’s Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. THALITONE can be used alone or in combination with other antihypertensive agents. 1.2 Edema Chlorthalidone is indicated in
  • adults as adjunctive therapy in edema associated with heart failure, cirrhosis of the liver, and renal disease, including nephrotic syndrome.

From the official label · 2026-06-25 · DailyMed

How it works

From this product’s own US prescribing label.

Chlorthalidone is a long-acting oral diuretic with antihypertensive activity.

The diuretic effects of chlorthalidone and the benzothiadiazine (thiazide) diuretics appear to arise from similar mechanisms and the maximal effect of chlorthalidone and the thiazides appear to be similar.

Half-life40–60 h
Mostly cleared after≈ 10 daysfive half-lives — our arithmetic
How it leaves the body

It is eliminated primarily as unchanged drug in the urine.

Quoted from the prescribing label, sections “Mechanism of Action” and “Pharmacokinetics”. DailyMed · 2026-06-25

Do not take it if

  • THALITONE is contraindicated in patients with anuria or hypersensitivity to chlorthalidone or other sulfonamide-derived drugs.
  • Anuria (4).
  • Hypersensitivity (4).

Quoted from the official label, section “Contraindications”.

How to take it

These directions are for this exact strength and form. Another one is different.

  • Initiate therapy with the lowest possible dose, then titrate according to individual patient response (2.1).
  • Hypertension:
  • Recommended initial dose is 15 mg daily with food. If additional blood pressure reduction is needed, increase the dose to 25 mg (2.2).
  • Edema:
  • Recommended initial dose is 50 mg to 100 mg daily or 100 mg on alternate days. Depending on response, dosage can be decreased or increased up to a maximum of 200 mg daily (2.3). 2.1 General Considerations THALITONE cannot be substituted with other formulations of chlorthalidone. Initiate therapy with the lowest possible dose, then titrate according to individual patient response. 2.2 Hypertension The initial recommended dose is 15 mg once daily with food. After 2 weeks, the dosage may be increased to a single daily dose of 25 mg if additional blood pressure reduction is needed. Doses above 25 mg are not expected to result in increased blood pressure reduction. 2.3 Edema The recommended initial dosage is 50 to 100 mg daily or 100 mg on alternate days. Depending on response, dosage can be decreased or increased up to a maximum of 200 mg daily.

Quoted from the official label, section “Dosage & Administration”.

Other warnings

  • Hypotension:
  • Higher risk for patients with impaired sympathetic response, volume-depletion or salt restriction (5.1).
  • Renal Impairment: Patients with pre-existing kidney disease may be at higher risk. (5.2).
  • Monitor serum electrolytes periodically (5.3). 5.1 Hypotension THALITONE may cause symptomatic hypotension. Patients with impaired sympathetic response, volume-depletion or who are salt restricted may be at increased risk for developing hypotension. If hypotension occurs, place the patient in the supine position and, if necessary, give intravenous normal saline. A transient hypotensive response is not a contraindication to further treatment, which usually can be continued without difficulty once the blood pressure has stabilized. 5.2 Impaired Renal Function Changes in renal function including acute renal failure can be caused by diuretics. Patients with chronic kidney disease, heart failure, or volume depletion may be at particular risk of developing acute renal failure on THALITONE. Monitor renal function periodically. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on THALITONE [see Drug Interactions (7)]. 5.3 Electrolyte Abnormalities THALITONE can cause hypokalemia, hyponatremia, hypochloremic alkalosis, and hypomagnesemia. Hypomagnesemia can result in hypokalemia which appears difficult to treat despite potassium repletion. Monitor serum electrolytes periodically. If hypokalemia is accompanied by clinical signs (e.g., muscular weakness, paresis, or ECG alterations), THALITONE should be discontinued. Correction of hypokalemia and any coexisting hypomagnesemia is recommended prior to the initiation of thiazides. 5.4 Metabolic Disturbances Chlorthalidone may alter glucose tolerance. Chlorthalidone may raise serum levels of cholesterol and triglycerides. Chlorthalidone may raise the serum uric acid level due to reduced clearance of uric acid and may cause or exacerbate hyperuricemia and precipitate gout in susceptible patients. Chlorthalidone decreases urinary calcium excretion and may cause elevations of serum calcium. Monitor calcium levels in patients with hypercalcemia receiving THALITONE.

Quoted from the official label, section “Warnings”.

Pregnancy and breastfeeding

  • Risk Summary Available data over decades from observational studies and reports with chlorthalidone use in pregnant women have not identified a drug-associated risk of major birth defects or miscarriage.
  • However, adverse fetal outcomes, including fetal or neonatal jaundice, thrombocytopenia, hypoglycemia, and electrolyte abnormalities have been reported following maternal use of thiazide diuretics ( see Clinical Considerations ).
  • Chlorthalidone should not be used as first-line therapy to treat hypertension in pregnancy.
  • Advise pregnant women of the potential risk to a fetus.
  • The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.
  • All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.
  • In the U.S. general population, the estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
  • Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Hypertension in pregnancy increases the maternal risk for pre-eclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section, and post-partum hemorrhage).
  • Hypertension increases the fetal risk for intrauterine growth restriction and stillbirth.
  • Fetal/Neonatal Adverse Reactions Thiazides can cross the placenta, and concentrations reached in the umbilical vein approach those in the maternal plasma.
  • Thiazides, like other diuretics, can cause placental hypoperfusion.
  • Use of thiazides during pregnancy is associated with a risk of fetal or neonatal jaundice, thrombocytopenia, hypoglycemia, and electrolyte abnormalities.
  • Thiazides do not prevent or alter the course of EPH (Edema, Proteinuria, Hypertension) gestosis (pre-eclampsia) and should not be used as first-line therapy to treat hypertension in pregnant women.
  • Data Animal Data Reproduction studies have been performed in the rat and the rabbit and have revealed no evidence of harm to the fetus due to chlorthalidone.The available data do not allow the calculation of comparisons between the exposure of chlorthalidone observed in animal studies to the systemic exposure that would be expected in humans.
  • IN SPECIFIC POPULATIONS
  • Pregnancy: May cause fetal harm (8.1).
  • Lactation: Breastfeeding not recommended (8.2).
  • Pediatrics: Safety and efficacy in children have not been established (8.4).
  • Geriatric Use:
  • No overall difference in responses versus younger patients but care should be taken in dose selection in patients with impaired renal function (8.5). 8.1 Pregnancy Risk Summary Available data over decades from observational studies and reports with chlorthalidone use in pregnant women have not identified a drug-associated risk of major birth defects or miscarriage. However, adverse fetal outcomes, including fetal or neonatal jaundice, thrombocytopenia, hypoglycemia, and electrolyte abnormalities have been reported following maternal use of thiazide diuretics ( see Clinical Considerations ). Chlorthalidone should not be used as first-line therapy to treat hypertension in pregnancy. Advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-associated maternal and/or embryo/fetal risk Hypertension in pregnancy increases the maternal risk for pre-eclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section, and post-partum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and stillbirth. Fetal/Neonatal Adverse Reactions Thiazides can cross the placenta, and concentrations reached in the umbilical vein approach those in the maternal plasma. Thiazides, like other diuretics, can cause placental hypoperfusion. Use of thiazides during pregnancy is associated with a risk of fetal or neonatal jaundice, thrombocytopenia, hypoglycemia, and electrolyte abnormalities. Thiazides do not prevent or alter the course of EPH (Edema, Proteinuria, Hypertension) gestosis (pre-eclampsia) and should not be used as first-line therapy to treat hypertension in pregnant women. Data Animal Data Reproduction studies have been performed in the rat and the rabbit and have revealed no evidence of harm to the fetus due to chlorthalidone.The available data do not allow the calculation of comparisons between the exposure of chlorthalidone observed in animal studies to the systemic exposure that would be expected in humans. 8.2 Lactation Risk Summary Chlorthalidone is present in human milk. There is no information regarding the effects of chlorthalidone on the breastfed infant or the effects on milk production. Because of the potential for chlorthalidone accumulation which may lead to serious adverse reactions in the breastfed infant (such as jaundice, thrombocytopenia, hyperglycemia, electrolyte abnormalities), advise patients that breastfeeding is not recommended during treatment with chlorthalidone. 8.4 Pediatric Use Safety and effectiveness in children have not been established. 8.5 Geriatric Use Clinical studies of THALITONE did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy. This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

Quoted from the official label, section “OTC — Pregnancy or Breast Feeding”.

Other medicines

  • Effect of chlorthalidone on other drugs Chlorthalidone may add to or potentiate the action of other antihypertensive drugs. Chlorthalidone and related drugs may increase the responsiveness to tubocurarine. Lithium renal clearance is reduced by chlorthalidone, increasing the risk of lithium toxicity. Monitor serum lithium levels during concomitant use.
  • Antihypertensive drugs:
  • Chlorthalidone may add to or potentiate the action of other antihypertensive drugs (7).
  • Lithium:
  • Lithium renal clearance is reduced by chlorthalidone, increasing the risk of lithium toxicity (7).

Quoted from the official label, section “Drug Interactions”.

If you take too much

In an emergency, call your local emergency number or a poison control centre.

  • Symptoms of acute overdosage include nausea, weakness, dizziness and disturbances of electrolyte balance.
  • The oral LD 50 of the drug in the mouse and the rat is more than 25,000 mg/kg body weight.
  • The minimum lethal dose (MLD) in humans has not been established.
  • There is no specific antidote but gastric lavage is recommended, followed by supportive treatment.
  • Where necessary, this may include intravenous dextrose-saline with potassium, administered with caution.

Quoted from the official label, section “Overdosage”.

Use in children

Safety and effectiveness in children have not been established.

Quoted from the official label, section “Pediatric Use”.

Use in older people

  • Clinical studies of THALITONE did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.
  • Other reported clinical experience has not identified differences in responses between the elderly and younger patients.
  • In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.
  • This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function.
  • Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

Quoted from the official label, section “Geriatric Use”.

Side effects

  • The following adverse reactions are described in more detail elsewhere in the label;
  • Hypotension [see Warnings and Precautions (5.1)]
  • Impaired Renal Function [see Warnings and Precautions (5.2)]
  • Electrolyte Abnormalities [see Warnings and Precautions (5.3)]
  • Metabolic Disturbances [see Warnings and Precautions (5.4)] The following adverse reactions have been observed, but there is not enough systematic collection of data to support an estimate of their frequency. Gastrointestinal System Reactions:
  • anorexia, gastric irritation, nausea, vomiting, cramping, diarrhea, constipation, jaundice (intrahepatic cholestatic jaundice), pancreatitis. Central Nervous System Reactions :
  • dizziness, paresthesias, headache. Hematologic Reactions:
  • leukopenia, agranulocytosis, thrombocytopenia, aplastic anemia. Dermatologic-Hypersensitivity Reactions:
  • purpura, photosensitivity, rash, urticaria, necrotizing angiitis (vasculitis) (cutaneous vasculitis), Lyell’s syndrome (toxic epidermal necrolysis). Cardiovascular Reaction:
  • Orthostatic hypotension. Other Adverse Reactions:
  • muscle spasm, weakness, restlessness, impotence, xanthopsia. The most frequently expected adverse drug reactions among patients receiving THALITONE are hypotension, dizziness, renal dysfunction, and electrolyte abnormalities (6). To report SUSPECTED ADVERSE REACTIONS, contact Casper Pharma LLC at 1-844-5-CASPER (1-844-522-7737) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

Quoted from the official label, section “Adverse Reactions”.

What to discuss with your doctor

  • Patients should inform their doctor if they have had an allergic reaction to chlorthalidone or other diuretics; kidney disease; gout; been taking lithium carbonate.
  • Patients should be cautioned to contact their physician if they experience any of the following symptoms of potassium loss:
  • excess thirst, tiredness, drowsiness, restlessness, muscle pains or cramps, nausea, vomiting or increased heart rate or pulse.
  • Patients should inform their doctor if they have symptoms of light-headedness or dizziness.
  • Pregnancy Advise a pregnant woman of the potential risk to a fetus. Advise females of reproductive potential to inform their prescriber of a known or suspected pregnancy [see Use in Specific Populations (8.1)] .
  • Lactation Advise females not to breastfeed during treatment with chlorthalidone [see Use in Specific Populations (8.2)] . Rx Only PIB00101-05 Manufactured for:
  • Casper Pharma LLC East Brunswick, NJ 08816 Made in India. Revised:
  • 12/2019

Quoted from the official label, section “Patient Counseling Information”.

Strengths and forms

  • FORMS AND STRENGTHS THALITONE 15 mg tablets are white biconvex, kidney shaped tablets with “L” on lower punch and “96” on the upper punch.
  • THALITONE 25 mg tablets are white biconvex, kidney shaped tablets with “L” on one side and “99” on the other side.
  • Tablets: 15 mg and 25 mg (3).

Quoted from the official label, section “Dosage Forms & Strengths”.

What it looks like and how it is packed

  • THALITONE (chlorthalidone) Tablets USP 15 mg are white biconvex, kidney shaped tablets with “L” on lower punch and “96” on the upper punch.
  • Bottles of 30 NDC 70199-017-30 Bottles of 100 NDC 70199-017-01 THALITONE (chlorthalidone) Tablets USP 25 mg are white biconvex, kidney shaped tablets with “L” on one side and “99” on the other side.
  • Bottles of 30 NDC 70199-001-30 Bottles of 100 NDC 70199-001-01
  • Store at 20 o to 25 o C (68 o to 77 o F). [See USP Controlled Room Temperature].
  • Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.

Quoted from the official label, section “How Supplied”.

What is in it

  • THALITONE (chlorthalidone USP) is an antihypertensive/diuretic supplied as 15 mg and 25 mg tablets for oral use.
  • It is a monosulfamyl diuretic that differs chemically from thiazide diuretics in that a double ring system is incorporated in its structure.
  • It is a racemic mixture of 2-chloro-5-(1-hydroxy-3-oxo-1-isoindolinyl) benzenesulfonamide, with the following structural formula:
  • Chlorthalidone is practically insoluble in water, in ether and in chloroform; soluble in methanol; slightly soluble in alcohol.
  • The inactive ingredients are colloidal silicon dioxide, lactose monohydrate, magnesium stearate, microcrystalline cellulose, povidone, sodium starch glycolate. chlorthalidone-struc-1.jpg

Quoted from the official label, section “Description”.

Ingredients people check for

Lactose, gluten, dyes, sugars and other ingredients that matter with an allergy, intolerance or diet — as this product’s FDA label lists them.

  • Lactoselactose monohydrateMilk sugar: matters with lactose intolerance or a milk allergy.

Quoted from the FDA label. A label that does not name an ingredient is not a guarantee that the product is free of it, and formulations change. With an allergy, check the pack and ask a pharmacist.

Same active substance, strength and form in other countries

Matched on active substance, strength and kind of form only. This is not a statement that the products are equivalent or interchangeable: other ingredients, release and approved uses can differ — ask a pharmacist before swapping.

Medicine passport: one printable page to show a pharmacist abroad

CanadaNo exact match for this strength and form

Every strength and form (7)

Details

Made byCasper Pharma LLC
Active substanceChlorthalidone
Used inHeart, blood pressure and circulation
Strength15 mg
FormTablet
RouteOral
Packs100 TABLET in 1 BOTTLE · 30 TABLET in 1 BOTTLE
NDC70199-017

Source: NDC Directory · 2026-09-13 · not reviewed by a clinician

Source: US Food and Drug Administration, NDC Directory. Reuse terms: US government work (FDA).

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