Defulide contains furosemide 40 mg, a loop diuretic — a “water tablet”. It is used to remove excess fluid in heart failure, kidney disease and liver disease, and sometimes for high blood pressure. It makes you pass urine markedly more, so timing the dose matters.
What is Defulide?
Defulide contains furosemide 40 mg, a loop diuretic. It is a Schedule 3 medicine in South Africa, registered under Y/18.1/135.
Furosemide acts on a specific part of the kidney — the loop of Henle — where it blocks the reabsorption of sodium. Salt that would have been returned to the body stays in the urine, and water follows it. The result is a substantial increase in urine output and a reduction in the fluid the body is holding.
Loop diuretics are the strongest diuretics in common use, considerably more powerful than the thiazides such as the hydrochlorothiazide in Ridaq. That strength is why they are the treatment of choice for fluid overload — and why they need more monitoring.
The effect is also fast. Taken by mouth, furosemide begins working within about an hour and the main effect is over in a few hours. That short, sharp action is why when you take it matters, which is covered below.
What is Defulide commonly used for?
Furosemide is prescribed to remove excess fluid:
- Heart failure, its most common use. When the heart pumps less effectively, fluid accumulates in the legs and lungs. Furosemide relieves the resulting swelling and breathlessness.
- Oedema — fluid retention causing swollen ankles, legs or abdomen — from cardiac, kidney or liver causes.
- Pulmonary oedema, fluid on the lungs, where it is used urgently.
- Kidney disease, where the kidneys are retaining fluid.
- Liver disease with ascites, fluid collecting in the abdomen, usually alongside spironolactone.
- High blood pressure, particularly where kidney function is reduced, though thiazides are generally preferred for uncomplicated hypertension.
In heart failure, it is worth being clear about what it does and does not do. Furosemide relieves the congestion — the swelling, the breathlessness, the weight gain from retained fluid — and it does so effectively. It does not improve the heart’s function or prolong life. The medicines that do that in heart failure are others: ACE inhibitors or ARBs, beta blockers, and newer agents. Furosemide manages symptoms alongside them, and both parts of the regimen matter.
How Defulide fits into this medicine category
Furosemide is a loop diuretic:
| Group | Examples | Strength and use |
|---|---|---|
| Loop diuretics | Furosemide (Defulide) | Strongest; fluid overload, heart failure |
| Thiazide diuretics | Hydrochlorothiazide (Ridaq) | Milder; long-term blood pressure control |
| Potassium-sparing | Spironolactone, amiloride | Retains potassium; heart failure, ascites |
| Calcium channel blockers | Amlodipine (Ciplavasc) | Blood pressure, angina |
| ACE inhibitors / ARBs | Enalapril, losartan | Blood pressure, heart failure, kidney protection |
People with heart failure are commonly on several of these together, each doing a different job. See the heart, blood pressure and circulation medicines hub.
What to check before using Defulide
Take it in the morning. The effect arrives within an hour and lasts several hours; taken late in the day it will interrupt your sleep. If a second dose is prescribed, take it early afternoon rather than in the evening.
Plan the first few doses around access to a toilet. The increase in urine is considerable, and people are frequently unprepared for it.
Tell your prescriber or pharmacist if:
- You have kidney or liver disease, or gout — furosemide can raise uric acid and trigger a flare.
- You have diabetes. It can affect blood sugar control.
- You have low blood pressure, or feel faint on standing.
- You have an enlarged prostate or difficulty passing urine.
- You are pregnant or breastfeeding.
- You take digoxin, lithium, an aminoglycoside antibiotic, or an anti-inflammatory such as diclofenac or ibuprofen — NSAIDs both reduce its effect and increase the risk to the kidneys.
- You take other blood pressure medicines or another diuretic.
Expect blood tests. Potassium, sodium and kidney function are checked periodically, and these are not optional.
Follow the dispensing label. This page does not set doses.
Possible cautions and when to ask a pharmacist or doctor
Potassium loss is the main concern. Furosemide removes potassium along with sodium, and low potassium causes muscle weakness, cramps, and disturbances of heart rhythm — which is more serious in anyone also taking digoxin. Some people are given potassium supplements or a potassium-sparing diuretic alongside it. Take these as directed.
Dehydration and low blood pressure. Too much fluid removal causes dizziness, extreme thirst, dry mouth and light-headedness on standing. During a hot spell, or an illness with vomiting or diarrhoea, ask whether the dose should be paused.
Weigh yourself. In heart failure, daily weight at the same time each morning is the most reliable early sign of fluid returning. A gain of about 2 kg over two or three days is worth reporting promptly — it usually precedes visible swelling or breathlessness.
Sodium can fall too, causing confusion, headache and nausea, particularly in older adults.
Gout flares can be triggered.
Do not stop it because you dislike the frequent urination. Fluid re-accumulates, and in heart failure that leads to hospital admission. Discuss the timing instead — it can usually be adjusted.
Seek medical attention for muscle weakness, cramps or palpitations; marked dizziness or fainting; confusion; very little urine despite taking it; increasing breathlessness, particularly lying flat; rapid weight gain or increasing swelling; severe thirst with dry mouth; hearing changes or ringing in the ears; or yellowing of the skin or eyes.
Related medicine guides
- Browse Heart, Blood Pressure & Circulation Medicines guides
- Read: Ciplavasc used for
- Read: Ridaq used for
Frequently asked questions
What is Defulide 40 mg used for? Removing excess fluid in heart failure, kidney disease and liver disease, and sometimes for high blood pressure. It contains furosemide.
Is it a water tablet? Yes. Furosemide is a loop diuretic, the strongest of the commonly used water tablets.
When should I take it? In the morning. It works within about an hour and will disturb your sleep if taken late in the day.
Why do I need blood tests? It removes potassium and sodium along with water, and affects kidney function. These are checked periodically to keep them in a safe range.
Why should I weigh myself daily? In heart failure, a rise of about 2 kg over two or three days signals fluid returning, usually before swelling or breathlessness appear. Report it promptly.
Can I take ibuprofen with it? Check with your doctor. Anti-inflammatories reduce its effect and increase the risk to the kidneys when combined with a diuretic.