pharmacopeia
GET
/api/v1/drug/chlorthalidone
2D structure
2-chloro-5-(1-hydroxy-3-oxo-2H-isoindol-1-yl)benzenesulfonamide
SMILES C1=CC=C2C(=C1)C(=O)NC2(C3=CC(=C(C=C3)Cl)S(=O)(=O)N)O
InChIKey JIVPVXMEBJLZRO-UHFFFAOYSA-N

Mechanism of action

Sourced from openFDA

Mechanism-of-action class: Sodium Chloride Symporter Inhibitors.

Sodium Chloride Symporter

Indications

Sourced from openFDA
  • Diuretics such as chlorthalidone are indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension. Chlorthalidone is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy.ICD-10: I10, I50.9, R60.9

Contraindications

Sourced from openFDA
  • Anuria. Known hypersensitivity to chlorthalidone or other sulfonamide-derived drugs.contraindicated

Dosage & administration

Sourced from openFDA

Therapy should be initiated with the lowest possible dose. This dose should be titrated according to individual patient response to gain maximal therapeutic benefit while maintaining lowest dosage possible. A single dose given in the morning with food is recommended; divided daily doses are unnecessary. Hypertension Initiation: Therapy, in most patients, should be initiated with a single daily dose of 25 mg. If the response is insufficient after a suitable trial, the dosage may be increased to a single daily dose of 50 mg. If additional control is required, the dosage of chlorthalidone may be increased to 100 mg once daily or a second antihypertensive drug (step 2 therapy) may be added. Dosage above 100 mg daily usually does not increase effectiveness. Increases in serum uric acid and decreases in serum potassium are dose-related over the 25 to 100 mg/day range. Maintenance: Maintenance doses may be lower than initial doses and should be adjusted according to individual patient response. Effectiveness is well sustained during continued use. Edema Initiation: Adults, initially 50 to 100 mg daily, or 100 mg on alternate days. Some patients may require 150 to 200 mg at these intervals or up to 200 mg daily. Dosages above this level, however, do not usually produce a greater response. Maintenance: Maintenance doses may often be lower than initial doses and should be adjusted according to individual patient response. Effectiveness is well sustained during continued use.

Warnings & precautions

Sourced from openFDA

Chlorthalidone should be used with caution in severe renal disease. In patients with renal disease, chlorthalidone or related drugs may precipitate azotemia. Cumulative effects of the drug may develop in patients with impaired renal function. Chlorthalidone should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma. Sensitivity reactions may occur in patients with a history of allergy or bronchial asthma. The possibility of exacerbation or activation of systemic lupus erythematosus has been reported with thiazide diuretics, which are structurally related to chlorthalidone. However, systemic lupus erythematosus has not been reported following chlorthalidone administration.

Adverse reactions

Sourced from openFDA

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, vertigo, paresthesias, headache, xanthopsia. 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 Reactions: orthostatic hypotension may occur and may be aggravated by alcohol, barbiturates, or narcotics. Other Adverse Reactions: hyperglycemia, glycosuria, hyperuricemia, muscle spasm, weakness, restlessness, impotence. Whenever adverse reactions are moderate or severe, chlorthalidone dosage should be reduced or therapy withdrawn.

Use in specific populations

Sourced from openFDA

Pregnancy Teratogenic Effects. Pregnancy Category B Reproduction studies have been performed in the rat and the rabbit at doses up to 420 times the human dose and have revealed no evidence of harm to the fetus due to chlorthalidone. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Nonteratogenic Effects Thiazides cross the placental barrier and appear in cord blood. The use of chlorthalidone and related drugs in pregnant women requires that the anticipated benefits of the drug be weighed against possible hazards to the fetus. These hazards include fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in the adult. Nursing Mothers Thiazides are excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from chlorthalidone, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. Pediatric Use Safety and effectiveness in children have not been established.

Overdosage

Sourced from openFDA

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.

Approval history

Sourced from openFDA
  • Feb 26, 1981ANDAANDA086831Mylan
  • Jun 8, 1984NDANDA018760Twi Pharms
  • Jul 21, 1986ANDAANDA089286Sun Pharm Industries
  • Dec 20, 1988NDANDA019574Casper Pharma Llc
  • Jul 2, 1992ANDAANDA073665Watson Labs
  • Dec 20, 2011NDANDA202331Azurity
  • Mar 30, 2017ANDAANDA206904Ingenus Pharms Llc
  • Mar 17, 2025NDANDA218647Prm Pharma

FAERS reports

View JSON
Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
14,339 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Drug Ineffective1,2859.0%
  2. 2Nausea1,2048.4%
  3. 3Fatigue1,0317.2%
  4. 4Off Label Use9366.5%
  5. 5Diarrhoea8175.7%
  6. 6Dizziness7505.2%
  7. 7Headache6944.8%
  8. 8Pain6844.8%
  9. 9Dyspnoea6534.6%
  10. 10Hypertension5483.8%
  11. 11Arthralgia5453.8%
  12. 12Asthenia5363.7%
  13. 13Acute Kidney Injury5283.7%
  14. 14Hyperhidrosis5193.6%
  15. 15Blood Pressure Increased5093.5%

Literature

View JSON

Recent PubMed references pinned to Chlorthalidone as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

View JSON

The 10 most recently updated of 108 ClinicalTrials.gov registrations naming Chlorthalidone as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Chlorthalidone work?
Mechanism-of-action class: Sodium Chloride Symporter Inhibitors.
What is Chlorthalidone used for?
According to FDA labeling, Chlorthalidone carries indications including: Diuretics such as chlorthalidone are indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension. Chlorthalidone is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Chlorthalidone?
Chlorthalidone is classified as Sulfonamides, plain, Thiazide-like Diuretic, Sodium Chloride Symporter Inhibitors, Decreased Blood Pressure, Decreased Intravascular Volume, Increased Distal Tubule Cl- Excretion, Increased Distal Tubule H+ Excretion, Increased Distal Tubule K+ Excretion, Increased Distal Tubule Na+ Excretion, Increased Diuresis.
What are the brand names for Chlorthalidone?
Chlorthalidone is marketed under brand names including Edarbyclor, Hemiclor, Tenoretic, Thalitone.
What are the contraindications for Chlorthalidone?
Chlorthalidone labeling lists contraindications including: Anuria. Known hypersensitivity to chlorthalidone or other sulfonamide-derived drugs.. Always consult the full prescribing information and a clinician.
Note. Data for chlorthalidone is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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