Get information on Hydrochlorothiazide | Plus affordable price - in the UK

Quick a high level overview

Hydrochlorothiazide is a well established prescription diuretic used mainly to reduce excess fluid and to help control high blood pressure. The active chemical is hydrochlorothiazide, a thiazide-group agent frequently prescribed either alone or in combination with other blood pressure medicines.

Decisions on dose, frequency and duration are made by the prescriber after assessing medical history and treatment response. If you need dosing details, see the dosing segment at How should this medicine be taken properly?.

Markers of change and common applications

Typical situations in which hydrochlorothiazide may be used include:

• Management of essential hypertension to lower blood pressure
• Reduction of fluid overload, for example in heart failure
• Control of oedema related to liver disease or some kidney problems
• Treatment of swelling associated with certain medications, such as corticosteroids

Any choice of treatment should follow consultation with a clinician. Come back toward the highest point on the page Proceed directly to the page top.

The available forms and strengths

In the UK hydrochlorothiazide is commonly supplied as oral tablets. Regularly encountered strengths are:

• 12.5 mg in total tablets
• 25 mg per tablet

Clinicians may select different strengths or fixed-dose combinations with other antihypertensives depending on the clinical situation. Look over the various a second option choices at Variants and quick comparisons.

What time of day should I take this medicine?

General practical points:

• Take tablets with a glass of water; they can usually be taken with or without food according to the prescriber advice.
• Because hydrochlorothiazide increases urine output many people take it in the morning to reduce night-time bathroom visits.
• Avoid starting potassium supplements or making large diet changes without medical advice; your prescriber will advise if supplements are needed.
• If you have any queries about timing, collaborative interactions are not just about words, but meaning. or missed doses speak to your pharmacist or doctor. To review guidance when a dose is missed, see the corresponding section area. Treatment guidance for prescribed dose was misseds.

For individualised dosing follow the exact instructions on your prescription from your clinician. Move back to the high point: Head to the number one spot of the page.

The pharmacology class and in what way it works

Hydrochlorothiazide is a thiazide diuretic. It acts in the kidney on the distal convoluted tubule to reduce reabsorption of sodium and chloride. The result is increased urine production, a decrease in circulating fluid volume and, with continued use, lowering of blood pressure and reduction of fluid accumulation.

For oversight and safety issues, consult the risk alerts section at Advisories and safety tips together with the drug side effects section at Common possible secondary effects and caution flags to look for.

After a dose is missed: guidance

If you skip a dose of hydrochlorothiazide take it as soon as you remember unless the next scheduled dose is imminent. Do not take two doses together to catch up.

If your dosing schedule is unusual or you have specific instructions from your prescriber, follow those. When unsure contact your healthcare provider or community pharmacist for advice.

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Storage device and disposal strategy

• Store tablets at normal room temperature, around 20 to 25 degrees C; short excursions between 15 and 30 degrees C are usually acceptable.
• Protect from excessive heat, damp and strong sunlight; do not keep medicines in a bathroom.
• Store medications where they are not reachable or visible to children and pets.

For disposal, use your local pharmacy returned-medicine scheme rather than throwing medicines in household waste. Go back to the tip top of the page: Up to the page top.

Health and user safety warning messages and cautionary measures

Protective measures and medical contrasigns indicating

• Allergy to hydrochlorothiazide or any tablet ingredient
• Anuria or severe inability to pass urine
• Concomitant use with certain drugs such as dofetilide or ketanserin due to serious interpersonal engagement risk

Use this with prudent caution.

• Swirling sensation or visual disturbances may occur; avoid driving or operating machines until you know how the medicine affects you.
• Stand up slowly from sitting or lying to reduce lightheadedness.
• Exposure to high heat, fever or heavy exercise increases the risk of dehydration and low sodium; tell your clinician if you expect prolonged heat exposure.
• Sensitivity to sunlight may increase; use sun protection or cover the skin as needed.
• Blood glucose may rise; people with diabetes should monitor levels and discuss any needed adjustments with their prescriber.
• Regular checks of electrolytes and kidney function are often recommended while taking thiazides.
• Uric acid can increase and may precipitate gout in susceptible people.
• Major communication in actions at scale reveal systemic patterns. include lithium (time sensitive monitoring needed), digoxin (risk increases if potassium is low) and additive blood pressure lowering with other antihypertensives.
• Inform any treating clinician, dentist or emergency team that you are taking hydrochlorothiazide before procedures.

Pregnancy through lactation

• Hydrochlorothiazide is usually avoided for treating hypertension in pregnancy because there may be fetal risks; contact your prescriber promptly if you become pregnant to discuss safer options.
• Small amounts can pass into breast milk besides the drug may reduce milk production; weigh benefits and risks with your clinician if breastfeeding.

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Latent effects and what to watch for

Mild, often transient long term effects can include:

• Feeling dizzy or lightheaded, especially when standing
• Occasional blurred vision
• Nausea and other GI complaints, constipation or diarrhoea
• Decreased urge to eat

Seek urgent medical attention if you experience any of the following symptoms. serious symptoms, including:

• Severe allergic reactions: rash, hives, swelling of face, lips or throat, breathing difficulty
• Fainting, severe confusion or persistent dizziness
• Fast, irregular or very slow heartbeat
• High fever, sore throat or signs of infection
• Marked decrease in urine or very dark urine
• Severe stomach pain, repeated vomiting or seizures
• Unusual bruising or bleeding, extreme tiredness
• Muscle cramps, numbness, tingling or other signs that may reflect electrolyte imbalance
• Yellowing of skin or eyes
• Sudden severe joint pain, swelling or redness suggesting gout

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Variants and quick comparisons

If hydrochlorothiazide is unsuitable there are other diuretics and blood pressure medicines commonly prescribed in the UK. The best a contingency option depends on the diagnosis, kidney function and side effect tolerance.

• Indapamide - a thiazide-like diuretic often recommended in some guidelines for blood pressure control; similar effects with different dosing considerations.
• Bendroflumethiazide - another thiazide agent, typically inexpensive and widely used.
• Chlortalidone - longer acting than hydrochlorothiazide and sometimes used for resistant hypertension.
• Furosemide - a loop diuretic producing stronger fluid removal; used mainly for heart failure related oedema.
• Spironolactone and eplerenone - mineralocorticoid receptor antagonists useful in resistant hypertension and certain forms of heart failure; require potassium vigilant monitoring.
• Non-diuretic antihypertensives - ACE inhibitors, ARBs, calcium channel blockers and beta blockers are commonly used either alone or in combination.

For a a quick price comparison in the UK see UK price norms and how they compare. Return again to on top: Return to the page's top

Costs in the United Kingdom and how they compare

Private retail prices vary by pharmacy, region and pack size. The following monthly expected costs (about 28 to 30 days supply) are approximate and for guidance only:

• Hydrochlorothiazide a dose of 12.5 mg or 25 mg: approximately 3 to 12 pounds
• Bendroflumethiazide: approximately 1 to 4 pounds
• Indapamide: approximately 2 to 7 pounds
• Chlortalidone: approximately 6 to 18 pounds
• Furosemide: approximately 1 to 5 pounds
• Spironolactone: approximately 2 to 10 pounds

On the NHS many patients in England pay a per-item prescription fee (check the current amount; it was 9.the weight of 90 pounds in 2026 Prescriptions are free for eligible groups and throughout Scotland, Wales and Northern Ireland for residents. Private online clinics may charge consultation and dispensing fees on top of medicine costs.

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UK regulatory and legal memorandum

• Classification: hydrochlorothiazide is a Prescription Only Medicine (POM) in the UK and requires a prescription from a UK-registered prescriber to be supplied by a UK pharmacy.
• Online purchases: use only pharmacies registered with the General Pharmaceutical Council (GPhC). Verify online suppliers using the GPhC register before buying.
• Importation rules: bringing prescription medicines into the UK without a valid prescription can contravene MHRA rules. Importing for other people or in large volumes may be unlawful.
• Driving and safety: do not drive if you experience latent effects such as dizziness or visual disturbance; follow DVLA guidance when applicable.
• Sporting considerations: diuretics are included on many sporting organisations prohibited lists (for example WADA/UKAD) because they may mask other substances; athletes should seek a Therapeutic Use Exemption where needed.
• Do not share prescription medicines. If in doubt, consult a pharmacist for safe use and intercommunication checks.

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Everyday tips and follow up

• Attend scheduled follow-up so your prescriber can check blood pressure, kidney function and electrolytes.
• If you are treated for diabetes, inform your team about any changes in medication as doses may need adjustment.
• Keep an up to date list of all medicines and show it to any healthcare professional you consult.
• Only the person named on a prescription should take that medicine. Do not share prescribed drugs with others.

For authoritative and current recommendations consult NHS guidance, MHRA publications or speak with your local pharmacist. Scroll to the topmost layer: Scroll to top