Cyclopenthiazide
Cyclopenthiazide is a thiazide-like diuretic used to treat high blood pressure and fluid retention (edema) caused by conditions such as heart failure, liver disease, or kidney disorders. It works by helping the kidneys remove excess salt and water from the body, which decreases blood volume and lowers blood pressure.
A diuretic that removes excess fluid from the body to treat high blood pressure and edema.
Key facts at a glance
- ATC
- C03AA07
- RxNorm
- 3000
- Generic
- Cyclopenthiazide
- Class
- atc-c03
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- 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
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg 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
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second third trimesterdiscontinue if pregnant
thiazides may cause fetal and neonatal issues including jaundice and thrombocytopenia
fetal growth monitoring and platelet counts
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingavoid
cyclopenthiazide is excreted in breast milk - avoid breastfeeding or discontinue drug
monitor infant electrolytes if exposure occurs
Use of this medication in this population requires careful consideration of risks and benefits.
geriatric
elderlystart with lower dose
increased sensitivity to orthostatic hypotension and electrolyte changes - use conservative dosing
monitor blood pressure, electrolytes and renal function regularly
Use with caution and monitor for adverse effects.
pediatric_age
children adolescentsnot recommended
not recommended for use in children due to limited safety and efficacy data
not applicable
Use of this medication in this population requires careful consideration of risks and benefits.
renal_impairment
mild to moderateuse with caution - may have reduced efficacy
thiazides less effective when creatinine clearance below 30 mL/min - monitor renal function
regular monitoring of renal function and electrolytes
Use with caution and monitor for adverse effects.
renal_impairment
severeavoid
thiazide diuretics generally ineffective when creatinine clearance below 30 mL/min
avoid use
Use of this medication in this population requires careful consideration of risks and benefits.
hepatic_impairment
moderate to severeuse with caution
use with caution in hepatic impairment - may precipitate hepatic encephalopathy
monitor electrolytes and hepatic function
Use with caution and monitor for adverse effects.
Statistics and clinical data
Drug class
Thiazide diuretics classification under ATC code C03AA
Common uses
Primary therapeutic indications
Mechanism of action
Pharmacodynamic mechanism
Commonly prescribed since
Historical prescribing information
Cyclopenthiazide is primarily used to treat essential hypertension (high blood pressure) and edema associated with congestive heart failure, liver cirrhosis, and certain kidney disorders. It may be used alone or in combination with other antihypertensive medications.
This medication works by blocking the sodium-chloride cotransporter in the distal convoluted tubule of the kidney. This action prevents reabsorption of sodium and chloride, leading to increased urinary excretion of these ions along with water. The reduction in fluid volume decreases cardiac output and ultimately lowers blood pressure.
Common side effects include electrolyte imbalances (particularly low potassium), increased urination, and photosensitivity. Patients should have their electrolyte levels monitored regularly. Cyclopenthiazide may worsen diabetes or gout and is generally avoided in patients with severe kidney impairment. Alcohol and concurrent use with other blood pressure medications may enhance hypotensive 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