Chlorthalidone
Chlorthalidone is a thiazide-like diuretic (water pill) used to treat high blood pressure and fluid retention (edema). It works by helping the kidneys remove excess salt and water from the body, which decreases blood volume and lowers blood pressure. This medication is typically used when other blood pressure medications alone are not sufficient.
Chlorthalidone is a diuretic that treats high blood pressure and edema by helping the body eliminate excess salt and water.
Key facts at a glance
- ATC
- C03BA04
- RxNorm
- 2409
- Generic
- Chlorthalidone
- Class
- atc-c03
- Brands
- Edarbyclor, Thalitone, Hemiclor, Tenoretic
- Availability
- rx
- Pregnancy
- B
- Lactation
- safe
- Routes
- oral
- Forms
- tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 25mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 0.5-2 mg/kg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 12.5-25mg once daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
8 groupspregnancy
first trimesteravoid if possible
use only if clearly needed and benefits outweigh risks
regular fetal monitoring and maternal blood pressure monitoring
Use with caution and monitor for adverse effects.
pregnancy
third trimesterdiscontinue before delivery if possible
avoid use near delivery due to risk of fetal toxicity
close fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingno specific adjustment
use with caution; small amounts excreted in breast milk
monitor infant for adequate weight gain
Use with caution and monitor for adverse effects.
geriatric
elderlystart at lower dose
use lower initial dose and titrate slowly; monitor for orthostatic hypotension
regular monitoring of electrolytes, renal function, and blood pressure
Use with caution and monitor for adverse effects.
pediatric_age
children adolescentsweight-based dosing required
not routinely recommended; use only if benefits clearly outweigh risks
monitor electrolytes and growth parameters
Use with caution and monitor for adverse effects.
renal_impairment
moderate ckdreduce dose
use with caution; thiazide diuretics less effective when CrCl < 30 mL/min
monitor renal function and electrolytes closely
Use with caution and monitor for adverse effects.
renal_impairment
severe ckdavoid or use alternative
thiazide diuretics generally ineffective when CrCl < 15 mL/min; consider loop diuretics instead
close monitoring if used
Use of this medication in this population requires careful consideration of risks and benefits.
hepatic_impairment
severeuse lower dose
use with extreme caution due to risk of electrolyte abnormalities and hepatic encephalopathy
monitor electrolytes, liver function, and mental status
Use with caution and monitor for adverse effects.
Statistics and clinical data
Drug class
Thiazide-like diuretic for hypertension and edema
Common uses
Primary therapeutic applications
Commonly prescribed since
Historical prescribing information
Brand names
Available brand name formulations
Chlorthalidone is primarily used to treat hypertension (high blood pressure) and edema associated with heart failure, kidney disorders, or liver cirrhosis. It may also be used to reduce the risk of cardiovascular events in some patients.
As a thiazide-like diuretic, chlorthalidone works in the distal convoluted tubule of the kidney by blocking the reabsorption of sodium and chloride ions. This leads to increased excretion of sodium, chloride, and water in the urine, reducing overall blood volume and cardiac output, which in turn lowers blood pressure.
Chlorthalidone may cause electrolyte imbalances (low potassium, sodium, magnesium) and increased uric acid levels. It can also increase blood sugar. Patients should have their electrolytes monitored regularly. Avoid use in severe renal impairment or anuria. Alcohol and concurrent use with other blood pressure medications may enhance blood pressure lowering effects.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 24, 2026. · Read our editorial policy