Hydrex (Hydrochlorothiazide) 25mg

It is one of the oldest and most widely prescribed blood pressure medicines in the world — often used alone or combined with other antihypertensives for better control.

How it works

Removes excess fluid

Kidneys excrete more salt and water in urine

Reduces blood volume

Less fluid in vessels means less pressure on artery walls

Lowers blood pressure

Sustained reduction in both systolic and diastolic readings

Dosage : 25 mg once daily

Dosage form: Oral tablet

Drug class : Thiazide Diuretic

Prescription : Required

What it's used for

High blood pressure (hypertension) — used alone or alongside other blood pressure medicines

Oedema (fluid retention) — reduces swelling caused by heart failure, liver cirrhosis, or kidney problems

Combination therapy — frequently paired with ACE inhibitors, ARBs, or beta-blockers for enhanced blood pressure control

Kidney stones — helps reduce calcium in urine, lowering the risk of calcium-type kidney stones in susceptible patients

How to take it

Take one tablet by mouth once daily, preferably in the morning with or without food. Taking it in the morning helps avoid frequent urination disrupting your sleep at night. Swallow whole with a glass of water.

You will likely urinate more frequently in the first few hours after taking this tablet — this is normal and expected. The effect settles down with regular use.

Common side effects

Most side effects relate to the diuretic action of the tablet and are manageable. These may include:

Low potassium is the most clinically important side effect. Your doctor may recommend potassium-rich foods (e.g. bananas, oranges) or periodic blood tests to monitor electrolyte levels during treatment.

Who should not take Hydrochlorothiazide 25 mg

People allergic to sulfonamide-derived medicines or to HCTZ itself

Patients with severely reduced kidney or liver function

Patients with very low potassium (hypokalaemia) or very low sodium (hyponatraemia)

Pregnant women — especially in the second and third trimester; may affect the unborn baby

Patients with gout — HCTZ can raise uric acid levels and trigger attacks

Patients with uncontrolled diabetes — may worsen blood sugar control

Important medicines to tell your doctor about

If taking cholestyramine or colestipol (bile acid resins), take HCTZ at least 1 hour before or 4 hours after to avoid reduced absorption.

Helpful tips while on this medicine

Stay well hydrated — drink adequate water throughout the day to replace fluids lost through increased urination

Use sunscreen outdoors — HCTZ can increase skin sensitivity to sunlight (photosensitivity)

Eat potassium-rich foods such as bananas, sweet potatoes, and leafy greens to help maintain electrolyte balance

Reduce salt intake — a low-sodium diet enhances the blood pressure-lowering effect of this medicine

Storage

Store below 25°C in a cool, dry place away from direct light and moisture. Keep out of reach of children.