cyclothiazide

Action and Spectrum

Actions and Spectrum: 

Action: 

Diuretic action: By preventing sodium and chloride ions from being reabsorbed in the distal convoluted tubules, cyclothiazide exerts its effects on the kidneys. This inhibition leads to increased excretion of water, sodium, chloride, potassium, and other electrolytes, thereby reducing fluid retention and lowering blood pressure. 

Spectrum: 

Cyclothiazide’s pharmacological spectrum includes its primary function as a diuretic agent, but it also exhibits effects on neurological pathways, particularly in modulating synaptic transmission and potentially aiding in the treatment of certain neurological conditions due to its influence on glutamate receptors. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Headache  

Dizziness 

Loss of appetite 

More frequent urination 

Diarrhea 

Black Box Warning

Black Box Warning:  

None

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Individuals with a known hypersensitivity or allergy to cyclothiazide or any of its components should avoid its use. 

Anuria: This is a condition where the kidneys can’t produce urine. cyclothiazide, being a diuretic, may worsen this condition or lead to severe electrolyte imbalances. 

Severe renal impairment: Patients with severe kidney problems may have difficulty excreting the drug properly, leading to potential toxicity and adverse effects. 

Severe hepatic impairment: Individuals with severe liver problems may have difficulty metabolizing cyclothiazide, leading to increased levels of the drug in the body and potential toxicity. 

Electrolyte imbalance: Cyclothiazide can cause alterations in electrolyte levels, especially potassium. Therefore, individuals with significant imbalances in electrolytes, particularly potassium, should use this medication cautiously or avoid it altogether. 

Pregnancy and breastfeeding: The safety of cyclothiazide during pregnancy and breastfeeding hasn’t been well established. It’s generally avoided unless the potential benefits outweigh the risks, and it’s recommended to consult a healthcare professional before using it in these situations. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology: Cyclothiazide is a diuretic and a member of the thiazide class of drugs, primarily used for the treatment of hypertension and edema. 

Pharmacodynamics:  

Inhibition of Sodium Reabsorption: Cyclothiazide mainly affects the kidneys by preventing the distal convoluted tubule of the nephron from reabsorbing sodium and chloride ions. By blocking the sodium-chloride symporter, it reduces the reabsorption of these ions, leading to increased excretion of sodium, chloride, and water in the urine. 

Potassium Loss: Thiazide diuretics like cyclothiazide further promote potassium ion excretion in the urine, leading to a potential loss of potassium. This effect can result in hypokalemia (low potassium levels), which might require monitoring or potassium supplementation.  

Pharmacokinetics: 

Absorption 

Cyclothiazide is orally administered and generally well-absorbed from the gastrointestinal tract. 

Its absorption can vary among individuals but is usually rapid and extensive, with peak plasma concentrations achieved within 1-2 hours after oral administration. 

Distribution 

After absorption, cyclothiazide is distributed widely throughout the body, including in tissues and organs. 

It crosses the blood-brain barrier and is found in the cerebrospinal fluid (CSF) to some extent. 

The drug binds extensively to plasma proteins. 

Metabolism 

Cyclothiazide undergoes minimal metabolism in the liver, with most of the medication being excreted in urine unchanged. 

Excretion and Elimination 

The primary route of elimination for cyclothiazide is via the kidneys, where it is primarily excreted unchanged in the urine. 

The elimination half-life of cyclothiazide ranges from about 5 to 15 hours, depending on various factors including renal function. 

Adminstartion

Administration:  

Cyclothiazide is usually administered orally in the form of tablets or capsules. It should be taken by mouth with a full glass of water. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: cyclothiazide 

Why do we use cyclothiazide?  

Cyclothiazide is used to help lower high blood pressure by reducing the volume of water in the blood vessels, which decreases the workload on the heart. 

It is used in the condition of edema associated with various conditions like congestive heart failure, liver disease, kidney problems, and certain medications.