Chlorthalidone: uses, dosing, side effects & brands
Chlorthalidone is a thiazide-like diuretic sold in the U.S. under 4 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.
Key facts
- Drug class
- Thiazide-Like Diuretic
- Treats
- Edema, Glomerulonephritis and Heart Failure
- Available as
- Tablet
- Sold as
- 4 products — Hygroton, Chlorthalidone and Hemiclor, and others
- Prescription?
- Prescription only
- Generic available?
- Yes
- Half-life
- about 40 hours on average (the label reports a mean half-life of 40 hours after a 50–200 mg dose, and an elimination half-life of 53 hours after 50 mg and 60 hours after 100 mg)
- What the pharmacy pays
- about $3 for a 30-count supply — not your price
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How chlorthalidone is dosed
From the FDA label for Hemiclor (application NDA218647). Other chlorthalidone products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
The recommended starting dose is 12.5 mg or 25 mg orally once daily ( 2.1 ). Dose may be doubled after 2 to 4 weeks as needed based on individual response, up to a maximal dose of 100 mg once daily ( 2.1 ) 2.1 Recommended Dosage Therapy should be initiated with the lowest possible dose. The recommended adult initial dose of HEMICLOR is 12.5 mg or 25 mg given orally with food once daily. Double the dosage every 2 to 4 weeks as needed based on individual patient response, up to a maximum of 100 mg once daily. Dosage above 100 mg daily usually does not increase effectiveness.
Chlorthalidone side effects
The following adverse reactions are described in more detail elsewhere in the label; Acute Kidney Injury [see Warnings and Precautions (5.1) ] Electrolyte Abnormalities [see Warnings and Precautions (5.2) ] Metabolic Disturbances [see Warnings and Precautions (5.3) ] The following adverse reactions have been observed with chlorthalidone, 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 thiazide-like diuretics are electrolyte abnormalities and metabolic disturbances ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact Ingenus Pharmaceuticals, LLC at 1-877-748-1970 or FDA at 1-800-FDA-1088 or…
Who shouldn’t take chlorthalidone
Chlorthalidone is contraindicated in patients with anuria, or hypersensitivity to chlorthalidone or other sulfonamide-derived drugs. Anuria ( 4 ). Hypersensitivity to chlorthalidone or other sulfonamide-derived drugs ( 4 ).
Chlorthalidone drug interactions
Effect of chlorthalidone on other drugs Insulin requirements in diabetic patients may be increased, decreased or unchanged. Higher dosage of oral hypoglycemic agents may be required. Chlorthalidone may increase the responsiveness to tubocurarine. Chlorthalidone may decrease arterial responsiveness to norepinephrine. This diminution is not sufficient to preclude effectiveness of the pressor agent for therapeutic use. Lithium renal clearance is reduced by chlorthalidone, increasing the risk of lithium toxicity. Monitor serum lithium levels during concomitant use. Insulin requirements and oral hypoglycemic agent dosages may require adjustments ( 7 ). Possible increased responsiveness to tubocurarine ( 7 ). Possible decreased arterial responsiveness to norepinephrine ( 7 ). Lithium renal clearance is reduced by chlorthalidone, increasing the risk of lithium toxicity ( 7 ).
Every chlorthalidone product we track (4)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 70/100 | Prescription | Tablet | Generic | $3 | View → | |
| 2 | Not yet rated | Prescription | Tablet | Generic | $3 | View → | |
| 3 | Not yet rated | Prescription | Tablet | Generic | $3 | View → | |
| 4 | Not yet rated | Prescription | Tablet | Generic | $3 | View → |
What chlorthalidone pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
Combination products containing chlorthalidone
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.
Chlorthalidone recalls
From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.
How long chlorthalidone keeps
No chlorthalidone 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 chlorthalidone expire? The in-use limits and storage rules from its labelsChlorthalidone and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for chlorthalidone: levels in milk, effects in breastfed infants, and the drugs it would consider insteadAlthough amounts of chlorthalidone in milk are not great, its slow clearance may lead to accumulation in the infant, especially while nursing a newborn or preterm infant. It may also suppress lactation. An alternate drug may be preferred.
National Institute of Child Health and Human Development, record revised July 15, 2026. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about chlorthalidone
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 13,022 reports naming chlorthalidone, and the FDA flagged 64% 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:
- fatigue1,013 reports
- nausea902 reports
- diarrhoea783 reports
- dizziness663 reports
- headache641 reports
- dyspnoea624 reports
- arthralgia568 reports
- hypertension502 reports
Read these as a signal, not a rate. A report does not mean chlorthalidone 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 July 25, 2026.
How long chlorthalidone stays in your system
The elimination half-life of chlorthalidone is about 40 hours on average (the label reports a mean half-life of 40 hours after a 50–200 mg dose, and an elimination half-life of 53 hours after 50 mg and 60 hours after 100 mg). This is an older-format label (CLINICAL PHARMACOLOGY, not a PLR §12.3), and it gives its numbers in two ways: a mean half-life of 40 hours across the 50–200 mg dose range, and dose-specific elimination half-lives of 53 hours (50 mg) and 60 hours (100 mg). Only one phase is described, so the figures above are the elimination values the label states — it does not report a separate distribution phase. No active metabolite is described: the label says chlorthalidone is largely excreted unchanged by the kidneys and that data on metabolites and non-renal elimination routes "have yet to be clarified." It is not a prodrug. Do not confuse the half-life with the duration of diuretic effect — the label describes diuresis beginning in about 2.6 hours and continuing up to 72 hours, which is a different measure. The label does NOT quantify how the half-life changes with age, kidney impairment, or liver impairment; it gives no geriatric or renal/hepatic pharmacokinetic numbers. It does warn that cumulative effects of the drug may develop in patients with impaired renal function, and to use caution in severe renal disease and in impaired hepatic function — but it does not state a half-life for those groups, so no number should be inferred for them.
DailyMed — CHLORTHALIDONE tablet (Clinical Pharmacology) ↗Half-life is how long the body takes to clear half a dose. It is not the same as how long a drug test can detect it, and it varies with age, kidney and liver function.
Related calculators
Frequently asked questions
What is chlorthalidone?
Hemiclor (Chlorthalidone) is a thiazide-like diuretic used to treat Edema, Glomerulonephritis, Heart Failure, Hypertension.
What kind of drug is chlorthalidone?
The FDA classifies chlorthalidone as a thiazide-like 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.
How long does chlorthalidone stay in your system?
The elimination half-life of chlorthalidone is about 40 hours on average (the label reports a mean half-life of 40 hours after a 50–200 mg dose, and an elimination half-life of 53 hours after 50 mg and 60 hours after 100 mg) — that is how long the body takes to clear half of a dose. This is an older-format label (CLINICAL PHARMACOLOGY, not a PLR §12.3), and it gives its numbers in two ways: a mean half-life of 40 hours across the 50–200 mg dose range, and dose-specific elimination half-lives of 53 hours (50 mg) and 60 hours (100 mg). Only one phase is described, so the figures above are the elimination values the label states — it does not report a separate distribution phase. No active metabolite is described: the label says chlorthalidone is largely excreted unchanged by the kidneys and that data on metabolites and non-renal elimination routes "have yet to be clarified." It is not a prodrug. Do not confuse the half-life with the duration of diuretic effect — the label describes diuresis beginning in about 2.6 hours and continuing up to 72 hours, which is a different measure. The label does NOT quantify how the half-life changes with age, kidney impairment, or liver impairment; it gives no geriatric or renal/hepatic pharmacokinetic numbers. It does warn that cumulative effects of the drug may develop in patients with impaired renal function, and to use caution in severe renal disease and in impaired hepatic function — but it does not state a half-life for those groups, so no number should be inferred for them. Half-life is not the same as how long a drug test can detect the drug, and it varies with age, kidney and liver function.
Can you take chlorthalidone 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 chlorthalidone 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 chlorthalidone sold under?
We track 4 chlorthalidone-containing products in the U.S.: Hygroton, Chlorthalidone, Hemiclor and Thalitone. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does chlorthalidone come in?
Across the brands we track, chlorthalidone is currently marketed as tablet, 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 chlorthalidone?
Yes. Our catalog lists 1 generic chlorthalidone 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 chlorthalidone been recalled?
The FDA's Enforcement database lists 2 recall records whose product description mentions chlorthalidone. The most recent: Chlorthalidone Tablets (Jun 5, 2026). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Chlorthalidone: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/chlorthalidone
- MLA
- “Chlorthalidone: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/chlorthalidone.
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 chlorthalidone on DailyMed (NIH) ↗.