Mechanism of Action: Inhibits sodium and chloride reabsorption in the distal tubules of the kidney, leading to increased urine production and reduced blood volume, thereby lowering blood pressure.
Indications
Primary Use: Treatment of hypertension (high blood pressure).
Other Uses: Management of edema (fluid retention) associated with heart failure, liver cirrhosis, or kidney disorders. Sometimes used for nephrolithiasis (kidney stones) prevention.
Dosage
Adults:
Hypertension: Typically 12.5 mg to 25 mg once daily. Maximum dose: 50 mg/day.
Edema:25 mg to 100 mg daily, in a single or divided dose.
Elderly: Start at a lower dose due to increased risk of dehydration and electrolyte imbalance.
Children:1 mg/kg/day divided into 1 or 2 doses (maximum 37.5 mg/day).
Administration
Method: Oral intake.
Precautions: Should be taken in the morning to avoid nocturia (frequent nighttime urination). Can be taken with or without food.
Risk of hypokalemia with: Loop diuretics, corticosteroids.
Food: High-sodium diets may reduce effectiveness.
Monitoring Parameters
Blood Pressure: Regular monitoring to assess therapeutic effect.
Electrolytes: Regular blood tests to check potassium, sodium, and kidney function.
Kidney Function: Monitor creatinine and BUN (blood urea nitrogen) levels.
Use in Children
Guidelines: Approved for pediatric use, with weight-based dosing. Monitor for dehydration and electrolyte imbalance.
Use in Pregnancy
FDA Category: B. Generally avoided due to risk of fluid shifts and electrolyte disturbances in the fetus.
Use in Elderly
Considerations: Higher risk of dehydration and electrolyte imbalance. Monitor closely.
Use in Kidney Disease
Adjustments:
Avoid in severe renal impairment (eGFR <30 mL/min).
Requires dose adjustments in mild-to-moderate renal disease.
Use in Liver Disease
Caution: Can worsen liver dysfunction in cirrhosis. Monitor for hepatic encephalopathy.
Patient Counselling Points
Medication Use: Take in the morning to avoid frequent urination at night.
Side Effects: Report muscle cramps, dizziness, or signs of dehydration (dry mouth, confusion).
Lifestyle: Maintain a balanced diet with sufficient potassium intake (e.g., bananas, oranges, spinach).
Table of Brand Names, Manufacturer, and Prices in USD
Brand Name
Manufacturer
Strength/Dosage Form
Price (USD)
Microzide
Pfizer
12.5 mg Capsule
$0.40
Esidrix
Novartis
25 mg Tablet
$0.50
Hydrodiuril
Merck
50 mg Tablet
$0.60
15 FAQs with Answers
What is Hydrochlorothiazide used for? – Mainly for high blood pressure and fluid retention.
How does Hydrochlorothiazide work? – It helps your kidneys remove excess salt and water, reducing blood pressure.
When should I take Hydrochlorothiazide? – Take it in the morning to avoid waking up frequently at night.
Can Hydrochlorothiazide cause dehydration? – Yes, it increases urine output, which can lead to dehydration.
Is Hydrochlorothiazide safe during pregnancy? – Generally avoided unless absolutely necessary.
What are signs of low potassium with Hydrochlorothiazide? – Muscle cramps, weakness, irregular heartbeat.
Can I drink alcohol while taking Hydrochlorothiazide? – Alcohol can worsen dizziness and should be used cautiously.
How long does it take for Hydrochlorothiazide to work? – The antihypertensive effect begins within 2 hours.
What should I do if I miss a dose? – Take it as soon as possible unless it’s close to the next dose.
Does Hydrochlorothiazide interact with other medications? – Yes, caution with NSAIDs, lithium, and other diuretics.
What should I avoid while taking Hydrochlorothiazide? – Excessive sun exposure, alcohol, and high-sodium diets.
Can Hydrochlorothiazide affect kidney function? – It may worsen kidney function if dehydration occurs.
Does Hydrochlorothiazide help with weight loss? – It reduces water weight but is not a weight-loss medication.
Who should not take Hydrochlorothiazide? – Patients with severe kidney disease or sulfa allergies.
How is Hydrochlorothiazide different from furosemide (Lasix)? – Hydrochlorothiazide is milder and used mainly for hypertension, while furosemide is a stronger diuretic for severe fluid retention.