Ridaq contains hydrochlorothiazide, a thiazide diuretic — a water tablet. It is used to lower high blood pressure and to reduce fluid retention in heart failure, kidney and liver conditions. Ridaq-12,5 contains 12.5 mg; higher strengths exist. It is a long-term medicine, and high blood pressure usually causes no symptoms.
What is Ridaq?
Ridaq contains hydrochlorothiazide. Ridaq-12,5 contains 12.5 mg per tablet, and it is also supplied in 25 mg and 50 mg strengths. It is manufactured in South Africa by Pharmacare and is a Schedule 3 medicine.
Hydrochlorothiazide is a thiazide diuretic, commonly called a water tablet. It acts on the kidneys, reducing how much sodium they reabsorb. Sodium carries water with it, so more of both leaves in the urine. That reduces the volume of fluid in the circulation, which lowers blood pressure.
There is a second effect that becomes more important over time: thiazides also relax the blood vessel walls. Much of the long-term blood-pressure benefit comes from that rather than from fluid loss, which is why the medicine keeps working after the initial diuretic effect settles.
You may notice more frequent urination in the first days or weeks. That usually eases. Taking the tablet in the morning avoids being woken at night.
What is Ridaq commonly used for?
Ridaq is prescribed for:
- High blood pressure (hypertension). This is the main use. Thiazides are long-established first-line blood-pressure medicines, used alone or combined with others.
- Fluid retention (oedema) from heart failure, kidney disease, liver disease, or certain medicines.
- Some kidney stone conditions, because thiazides reduce calcium in the urine.
- Diabetes insipidus, in specific circumstances.
The 12.5 mg strength is most often used for blood pressure, sometimes as part of a combination tablet with another class. Higher strengths are more often used where fluid removal is the aim.
The central point about this medicine is the same as for any blood-pressure treatment: high blood pressure usually causes no symptoms at all. You take Ridaq not to feel better today but to reduce the risk of stroke, heart attack, heart failure and kidney damage over years. People stop because they feel fine — and feeling fine is generally the medicine working.
How Ridaq fits into this medicine category
Ridaq is a thiazide diuretic, one of several classes lowering blood pressure by different routes:
| Class | Examples | How it lowers pressure |
|---|---|---|
| Thiazide diuretics | Hydrochlorothiazide (Ridaq), indapamide | Removes sodium and water; relaxes vessels |
| Loop diuretics | Furosemide | Removes fluid strongly; mainly for overload |
| Potassium-sparing | Spironolactone, amiloride | Removes fluid while retaining potassium |
| Calcium channel blockers | Amlodipine, Ciplavasc | Relaxes artery walls |
| ACE inhibitors | Enalapril | Relaxes vessels via a hormonal pathway |
| Beta blockers | Various | Slows the heart, reduces its workload |
The diuretics are not interchangeable. Furosemide is a much stronger loop diuretic used mainly for fluid overload in heart failure. Spironolactone spares potassium and needs different monitoring. Hydrochlorothiazide is the usual thiazide choice for blood pressure. Being switched between them reflects what is being treated, not a failure of the first.
See the blood pressure, heart and circulation medicines hub.
What to check before using Ridaq
Take it in the morning. An evening dose means getting up at night to pass urine.
Tell your prescriber or pharmacist if:
- You have gout, or have had it. Thiazides raise uric acid and can trigger an attack.
- You have diabetes. Thiazides can raise blood glucose slightly.
- You have kidney or liver disease.
- You have low potassium or sodium, or have had them.
- You have lupus, which thiazides can occasionally aggravate.
- You are pregnant, planning pregnancy or breastfeeding. Blood-pressure medicines are chosen carefully in pregnancy.
- You take lithium — thiazides raise its level and toxicity risk.
- You take digoxin, where low potassium becomes more dangerous.
- You take anti-inflammatories such as ibuprofen or diclofenac. NSAIDs raise blood pressure and, combined with a diuretic and an ACE inhibitor, place real strain on the kidneys.
- You take other blood-pressure medicines, which is common and usually intentional.
Expect blood tests. Sodium, potassium and kidney function are checked when starting and periodically after. This is not routine paperwork — it is the specific monitoring this medicine needs.
Follow the dispensing label. This page does not set doses.
Possible cautions and when to ask a pharmacist or doctor
Do not stop because you feel well. Feeling well is the point of the treatment.
Low potassium is the main metabolic concern. It can cause muscle weakness, cramps, palpitations and, if severe, dangerous heart rhythms. Report persistent cramps, unusual weakness or palpitations. Your doctor may check levels, adjust the dose or suggest dietary changes.
Low sodium can cause confusion, headache, nausea and drowsiness, particularly in older people. It needs prompt assessment.
Dehydration. During a vomiting or diarrhoeal illness, or in very hot weather, a diuretic can tip you into dehydration and affect kidney function. Ask your prescriber whether to pause it when you are unwell — this is a practical question worth settling in advance.
Gout attacks can be triggered. Report a suddenly painful, swollen joint, classically the big toe.
Stand up slowly, particularly when starting.
Sun sensitivity occurs in some people. Use sun protection.
Seek medical attention for fainting, palpitations or an irregular heartbeat, severe muscle weakness or cramps, confusion, a significant reduction in urine, or a rash with blistering. Seek emergency care for chest pain, sudden breathlessness or symptoms of stroke.
Related medicine guides
- Browse Blood Pressure, Heart & Circulation Medicines guides
- Read: Ciplavasc used for
- Read: Austell Amlodipine used for
Frequently asked questions
What is Ridaq 12.5 mg used for? Mainly lowering high blood pressure. It contains hydrochlorothiazide, a thiazide diuretic. Higher strengths are more often used for fluid retention.
Is Ridaq a water tablet? Yes. It increases how much sodium and water the kidneys remove, which lowers blood pressure and reduces fluid retention.
Why do I need to urinate more often? That is the diuretic effect, and it usually eases after the first days or weeks. Taking it in the morning avoids disturbed sleep.
Can I stop once my blood pressure is normal? Not on your own. Normal readings usually mean the medicine is working. Any change is your prescriber’s decision.
Can I take ibuprofen with it? Ask first. Anti-inflammatories raise blood pressure and, combined with a diuretic, can affect the kidneys.
Why do I need blood tests? To check sodium, potassium and kidney function. Thiazides can lower potassium and sodium, and monitoring catches that early.