Natrixam is a single daily tablet combining indapamide with amlodipine, for high blood pressure. It pairs a thiazide-like diuretic with a calcium channel blocker — two different mechanisms in one tablet, which controls blood pressure better than pushing either alone to its maximum.
What is Natrixam?
The South African Medicine Price Registry lists Natrixam as Schedule 3 modified-release tablets:
| Product | Contains |
|---|---|
| Natrixam 1.5/5 mg | Indapamide 1.5 mg + amlodipine 5 mg |
| Natrixam 1.5/10 mg | Indapamide 1.5 mg + amlodipine 10 mg |
The indapamide stays at 1.5 mg while the amlodipine doubles. Moving from 1.5/5 to 1.5/10 is an increase in the amlodipine component only.
The two ingredients lower blood pressure by different routes:
Indapamide is a thiazide-like diuretic. It reduces sodium reabsorption in the kidney, so more sodium and water leave in the urine — and it also relaxes blood vessel walls directly. That second effect is why it works at doses too low to cause much diuresis, and why many people notice no increase in urination at all.
Amlodipine is a calcium channel blocker. It blocks calcium entering the muscle cells of artery walls, so the arteries relax and widen, reducing the resistance the heart pumps against.
Why combine them? Because the two mechanisms complement each other, and because combination therapy at moderate doses generally controls blood pressure better, with fewer side effects, than a single medicine pushed to its maximum.
Being moved to a combination tablet is usually good prescribing, not a sign of deterioration — which is worth saying, because it is commonly read the other way.
What is Natrixam commonly used for?
- High blood pressure (hypertension) — its sole use, as a substitute where both ingredients are already being taken separately, or as a step up.
- Reducing the risk of stroke, heart attack, heart failure and kidney damage, which is the actual purpose of treating blood pressure at all.
It is not a starting treatment. Natrixam is generally used where someone is already established on indapamide and amlodipine separately, or where one alone has not achieved target. Combination tablets improve adherence — one tablet is easier to remember than two — and that matters, because adherence is the main reason blood pressure treatment fails in practice.
Two points about what treating blood pressure means:
It is preventive, not symptomatic. High blood pressure causes no symptoms until it causes a stroke, heart attack or kidney failure. Nobody feels better on treatment — which is precisely why people stop, and why that decision is so costly.
It is usually lifelong. Blood pressure rises again within weeks of stopping. A normal reading on treatment means the medicine is working, not that it is no longer needed.
Lifestyle still counts: reducing salt, losing excess weight, regular activity, moderating alcohol and stopping smoking all lower blood pressure genuinely, and can sometimes reduce how much medicine is needed.
How Natrixam fits into this medicine category
| Group | Examples | How it works |
|---|---|---|
| Thiazide-like diuretics | Indapamide (in Natrixam), hydrochlorothiazide (Ridaq) | Remove salt and water; relax vessels |
| Calcium channel blockers | Amlodipine (in Natrixam, Ciplavasc) | Relax arteries |
| ACE inhibitors | Enalapril, perindopril | Block a hormone that narrows vessels |
| ARBs | Losartan, telmisartan | Similar, without the cough |
| Beta blockers | Carvedilol, bisoprolol | Slow the heart |
| Combination tablets | Natrixam and similar | Two mechanisms, one tablet, better adherence |
See the heart and blood pressure medicines hub.
What to check before using Natrixam
Tell your doctor or pharmacist if you:
- Have kidney disease or liver disease, particularly cirrhosis.
- Have gout, or have had it. Indapamide raises uric acid and can trigger an attack.
- Have diabetes — blood sugar can rise slightly, so monitor more closely at first.
- Have low potassium or sodium, or a condition causing them.
- Have a heart rhythm problem or a long QT interval, or take medicines affecting heart rhythm.
- Have severe heart failure or significant aortic valve narrowing — relevant to the amlodipine.
- Take lithium — indapamide raises lithium levels, and this needs careful monitoring.
- Take digoxin, other diuretics, ACE inhibitors or ARBs, steroids, or anti-inflammatories. Regular NSAIDs reduce the blood-pressure-lowering effect and, with a diuretic, can affect the kidneys.
- Take simvastatin, whose dose may need limiting with amlodipine.
- Are pregnant, planning pregnancy or breastfeeding — diuretics and amlodipine are generally avoided.
- Are elderly, where dehydration, low sodium and falls are more likely.
Practical points:
- Take it once daily in the morning, so any diuretic effect falls during the day.
- Swallow the tablet whole — it is modified-release and should not be crushed or chewed.
- Keep your blood tests. Kidney function, sodium, potassium and sometimes uric acid are checked periodically — routine, not a sign of a problem.
- Get up slowly from sitting or lying, especially at first.
- Avoid grapefruit juice, which raises amlodipine levels.
- Take care in hot weather and during vomiting or diarrhoea illness, when dehydration develops quickly.
- Do not stop because your reading is normal.
Possible cautions and when to ask a pharmacist or doctor
Common effects reflect both ingredients: ankle swelling, flushing, headache and dizziness from the amlodipine; increased urination (often mild), muscle cramps and sensitivity to sunlight from the indapamide.
Ankle swelling is the commonest reason people stop amlodipine. It is not fluid overload and does not respond to a diuretic — it is fluid pushed into the tissues by the vessels widening. Elevating the legs helps, and if it is troublesome the dose can be reduced or the medicine changed. Tell your doctor rather than stopping.
Seek prompt medical advice for:
- Muscle weakness, cramps, palpitations or an irregular heartbeat — possible low potassium.
- Confusion, marked drowsiness, headache with nausea, or unusual unsteadiness — possible low sodium, more common in older people and often gradual.
- Fainting, or persistent dizziness on standing.
- A sudden painful, hot, swollen joint — often the big toe — which may be gout.
- Marked reduction in urine output, or worsening swelling.
- A rash, particularly in sun-exposed areas.
Get emergency help for chest pain, severe breathlessness, signs of a stroke, or swelling of the face, lips or tongue with difficulty breathing.
Contact your doctor if readings stay high, if you develop a vomiting or diarrhoea illness and cannot drink normally, if another prescriber starts you on a new medicine, or if side effects are making you consider stopping. Almost every side effect here has an alternative — there are many blood pressure medicines, and stopping altogether is the one option with a real cost.
Related medicine guides
Frequently asked questions
What is Natrixam used for? Lowering high blood pressure. It combines indapamide, a thiazide-like diuretic, with amlodipine, a calcium channel blocker.
What is Natrixam 1.5/5 mg used for? The same purpose — 1.5 mg of indapamide with 5 mg of amlodipine. The 1.5/10 version doubles the amlodipine only.
Why two medicines in one tablet? Two mechanisms control blood pressure better, with fewer side effects, than pushing one to its maximum — and one tablet is easier to take consistently than two.
Does being moved to a combination mean I am worse? Usually not. Combination tablets are standard practice and improve adherence.
Why are my ankles swollen? A common amlodipine effect — fluid pushed into the tissues by widened vessels. It does not respond to a diuretic. Elevate your legs and tell your doctor rather than stopping.
Can I stop when my blood pressure is normal? No. A normal reading means the medicine is working. Blood pressure rises again within weeks of stopping.
Can I crush the tablet? No. It is modified-release and must be swallowed whole.
Can I drink grapefruit juice? No. It raises amlodipine levels and increases side effects.