Duforzig contains dapagliflozin 10 mg, an SGLT2 inhibitor. It is used for type 2 diabetes, and also for heart failure and chronic kidney disease — including in people who do not have diabetes. It works by making the kidneys excrete glucose in the urine.
What is Duforzig?
Duforzig is registered in South Africa as Schedule 4 — prescription-only:
| Product | Contains |
|---|---|
| Duforzig 10 | Dapagliflozin propanediol 10 mg tablet |
Dapagliflozin is an SGLT2 inhibitor — a sodium-glucose co-transporter 2 inhibitor.
Its mechanism is genuinely unusual. The kidneys filter a large amount of glucose out of the blood every day and then reabsorb almost all of it, mostly through a transporter called SGLT2. Dapagliflozin blocks that transporter, so glucose is not reclaimed and leaves in the urine instead.
Two consequences follow, and both matter:
- Blood glucose falls, without any involvement of insulin. Because it does not force insulin release, it does not usually cause low blood sugar on its own.
- Glucose in the urine carries water and sodium with it, producing a mild diuretic effect and modest weight loss. This is not a side effect — it is central to why the medicine helps the heart and kidneys.
That heart and kidney benefit is the most important thing about this class. Large trials found SGLT2 inhibitors reduce hospitalisation for heart failure and slow the progression of chronic kidney disease — in people with and without diabetes. The effects are larger than blood glucose lowering alone would explain, and they have changed how heart failure and kidney disease are treated.
So being prescribed Duforzig does not necessarily mean you have diabetes. If you have heart failure or kidney disease, it may have been prescribed for the heart or kidney protection. If you are unsure which applies to you, ask — it changes what you monitor.
What is Duforzig commonly used for?
- Type 2 diabetes, to lower blood glucose, usually alongside metformin.
- Heart failure, with reduced or preserved ejection fraction, to reduce hospitalisation and improve symptoms — with or without diabetes.
- Chronic kidney disease, to slow progression — again with or without diabetes.
- Reducing cardiovascular risk in type 2 diabetes with established heart disease.
It is not used for type 1 diabetes outside specialist settings, because of the ketoacidosis risk described below.
It causes modest weight loss — typically a few kilograms — because glucose lost in urine represents lost calories. That is a genuine effect but not the reason it is prescribed, and it is smaller than with GLP-1 medicines such as semaglutide.
It also modestly lowers blood pressure, through the mild diuretic effect.
How Duforzig fits into this medicine category
| Group | Examples | How it works |
|---|---|---|
| SGLT2 inhibitors | Dapagliflozin (Duforzig), empagliflozin | Excrete glucose in urine; heart and kidney benefits |
| Biguanides | Metformin | Reduces liver glucose output; usually first-line |
| Sulfonylureas | Gliclazide, glimepiride | Stimulate insulin release; hypos and weight gain |
| DPP-4 inhibitors | Sitagliptin, vildagliptin | Enhance the body’s own incretin response |
| GLP-1 agonists | Semaglutide (Ozempic) | Injected; lower glucose and reduce weight substantially |
| Insulin | Various | Replaces or supplements the body’s own insulin |
Metformin is usually the starting point, with an SGLT2 inhibitor added — often early, if there is heart or kidney disease. See the endocrine and diabetes medicines hub.
What to check before using Duforzig
Know the sick day rules. This is the most important safety point. Temporarily stop Duforzig if you become acutely unwell — with vomiting, diarrhoea, a significant infection, or if you cannot eat or drink normally — and restart when you are eating and drinking properly. Dehydration and illness are what precipitate the serious complication below. Ask your doctor to confirm this advice for you.
Stop it before major surgery or prolonged fasting, and tell any hospital or surgical team that you take it.
Maintain good genital hygiene and drink adequate fluids. Because glucose is being excreted in urine, genital fungal infections are considerably more common on this medicine — a predictable consequence rather than an unlucky one.
Tell your doctor or pharmacist if you:
- Have type 1 diabetes, where it is generally not used.
- Have had diabetic ketoacidosis before.
- Have kidney disease. It is used in kidney disease, but function is monitored and there is a threshold below which it is not started.
- Have recurrent urinary or genital infections.
- Are on a very low carbohydrate or ketogenic diet, which raises ketoacidosis risk.
- Drink alcohol heavily.
- Have low blood pressure, or are prone to dehydration.
- Take diuretics, whose effect adds to it.
- Take insulin or a sulfonylurea — the dose may need reducing to avoid hypos.
- Are elderly, where dehydration and low blood pressure matter more.
- Are pregnant, planning pregnancy or breastfeeding. It is not used in pregnancy.
- Have a foot ulcer or poor circulation in the feet.
Possible cautions and when to ask a pharmacist or doctor
Common effects are genital thrush, urinary tract infections, passing more urine, thirst, and dizziness on standing. Genital fungal infection is the effect people most often encounter, and it is readily treatable — mention it rather than stopping the medicine.
Seek medical attention urgently if you develop:
- Nausea, vomiting, abdominal pain, deep or rapid breathing, unusual drowsiness, thirst, or a sweet or fruity smell on the breath — possible diabetic ketoacidosis. This is a medical emergency, and the critical point is that with SGLT2 inhibitors it can occur even when blood glucose is normal or only mildly raised — so a normal glucose reading does not rule it out. Tell emergency staff you take an SGLT2 inhibitor.
- Pain, tenderness, redness or swelling in the genital or perineal area, with fever or feeling very unwell — a rare but serious infection needing immediate treatment.
- Fever, burning on urination, back or flank pain — possible kidney infection.
- Severe dizziness or fainting.
- Much less urine than usual.
- A new foot ulcer, or a wound that is not healing.
- Swelling of the face, lips or tongue, or a severe rash.
Do not stop it because your glucose readings are good, or because you feel well — if it was prescribed for heart failure or kidney disease, it is protecting those organs regardless of glucose.
Contact your doctor if you have recurrent genital or urinary infections, if you are becoming dehydrated, or before any procedure or period of fasting.
Related medicine guides
Frequently asked questions
What is Duforzig used for? Type 2 diabetes, heart failure and chronic kidney disease. It contains dapagliflozin, an SGLT2 inhibitor.
What is Duforzig 10 used for? 10 mg is the standard strength, used for all three of those indications.
Do I have diabetes if I am taking it? Not necessarily. Dapagliflozin is also prescribed for heart failure and chronic kidney disease in people without diabetes. Ask your doctor which applies to you.
How does it work? It blocks the kidney transporter that reclaims glucose, so glucose leaves in the urine instead of returning to the blood.
Why does it cause thrush? Glucose in the urine encourages fungal growth around the genital area. It is common, predictable and treatable — mention it rather than stopping the medicine.
Does it cause low blood sugar? Not usually on its own, since it does not force insulin release. Hypos become a risk when combined with insulin or a sulfonylurea.
Should I stop it if I am ill? Yes, temporarily, if you are vomiting, have diarrhoea, or cannot eat and drink normally — and restart when you are well. Confirm this with your doctor.
What is ketoacidosis and why does it matter here? A serious build-up of ketones. With SGLT2 inhibitors it can occur even with normal blood glucose, so a normal reading does not rule it out. Treat the symptoms as an emergency.