An iron-based chewable phosphate binder for kidney disease
Sucroferric oxyhydroxide
An iron-based phosphate binder, chewed with meals, to lower high phosphate levels in chronic kidney disease.
What is Sucroferric oxyhydroxide?
Sucroferric oxyhydroxide is an iron-based phosphate binder used to lower high phosphate levels in people with chronic kidney disease who are on dialysis. Like other binders it works in the gut, grabbing hold of phosphate from food so it is passed out in the stool rather than absorbed, which is why it is taken with meals. It comes as chewable tablets that should be chewed, not swallowed whole. Because it contains iron, it commonly turns the stools black, which is harmless and expected. The most common side effect is diarrhoea, especially early on.
Education and reference only. This is a plain-language guide to Sucroferric oxyhydroxide — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Sucroferric oxyhydroxide is a phosphate binder based on iron, used in people with chronic kidney disease on dialysis who have too much phosphate in their blood. It does not contain calcium. It is taken as chewable tablets with meals, and it works in the gut, with very little iron absorbed into the body. A characteristic, harmless effect of the iron is that it usually turns the stools black. It is a long-term treatment used as part of kidney care, alongside a low-phosphate diet and other measures, and is prescribed and monitored by the kidney team.
How it works
In chronic kidney disease the kidneys can no longer clear phosphate properly, so it builds up and over time can harm the bones, heart and blood vessels. Sucroferric oxyhydroxide uses iron to bind the phosphate from the food you eat, forming a substance the body cannot absorb, which is then passed out in the stool. Because it works on the phosphate in your meals, it is taken with food, and it is used regularly to keep phosphate under control. Only a tiny amount of the iron is absorbed, so it is the binding action in the gut, not iron replacement, that matters here.
Company & origin
Originated / developed by: Specialist manufacturers.
An iron-based medicine used in the UK to lower high phosphate levels in people with chronic kidney disease on dialysis.
What it treats
Conditions Sucroferric oxyhydroxide is used for
Practical use
How to take Sucroferric oxyhydroxide
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it with meals, as it works by binding the phosphate in the food you eat.
- Chew the tablets rather than swallowing them whole.
- Do not be alarmed if your stools turn black; this is a harmless, expected effect of the iron.
- Keep it apart in time from some other medicines, as it can stop them being absorbed properly.
- Follow the low-phosphate diet you are given, with help from a dietitian.
Weighing it up
Advantages & disadvantages of Sucroferric oxyhydroxide
Advantages
- Effectively lowers high phosphate levels in people on dialysis.
- Does not contain calcium, which suits people who need to limit calcium.
- Often needs fewer tablets per meal than some other binders.
Disadvantages
- Commonly causes diarrhoea, especially when treatment first starts.
- Turns the stools black, which, although harmless, can be alarming.
- Must be chewed and taken with every meal, and can affect some other medicines.
Practical use
Good to know
Two practical points stand out with sucroferric oxyhydroxide. First, because it contains iron, it very commonly turns the stools black; this is harmless and expected, not a sign of bleeding, though black stools from other causes should always be mentioned to your team if you are unsure. Second, the tablets are meant to be chewed, not swallowed whole, and are taken with meals so they can bind the phosphate in your food. The most common side effect is diarrhoea, which is often worse at the start and tends to settle. Like other non-calcium binders it suits people who need to limit calcium. It can affect the absorption of some other medicines, so certain tablets are taken at a separate time. A low-phosphate diet, with a dietitian's help, and regular blood tests work alongside it.
Who should not take it / use with caution
- People with a blocked bowel should not take it.
- People who have had a serious allergic reaction to it should not take it.
- It is used with care in people with certain bowel or liver conditions, under specialist guidance.
Monitoring
- Regular blood tests to check phosphate and related mineral levels.
- Reviewing how well levels are controlled and adjusting the dose with meals.
- Watching for diarrhoea and overall tolerance.
Side effects
- Diarrhoea, especially early in treatment.
- Black-coloured stools, which are harmless and expected.
- Nausea, indigestion or an unusual taste in some people.
Key interactions
- It can reduce the absorption of some other medicines, so certain tablets are taken at a separate time.
- Tell your team about all your medicines so timing can be arranged to avoid clashes.
- It is used alongside dietary phosphate restriction rather than instead of it.
Available as: Chewable tablets and an oral powder, taken with meals.
Answers
Sucroferric oxyhydroxide: frequently asked questions
What is sucroferric oxyhydroxide used for?
It is an iron-based phosphate binder used to lower high phosphate levels in people with chronic kidney disease on dialysis.
Why have my stools turned black?
Because it contains iron, it very commonly turns the stools black; this is harmless and expected, not a sign of bleeding.
Why must I take it with food?
It works by binding the phosphate in your meals so it passes out in the stool, so it is taken with food and chewed rather than swallowed whole.
What is the most common side effect?
Diarrhoea is the most common side effect, often worse at the start of treatment and tending to settle over time.
Does it contain calcium?
No, it is iron-based and does not contain calcium, which can suit people who need to limit their calcium intake.
The wider class
About Phosphate binder (iron-based)
Sucroferric oxyhydroxide belongs to the phosphate binder (iron-based) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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