Calcium acetate

How it works

Taken with food, it binds dietary phosphate in the gut to form insoluble, non-absorbed calcium phosphate, reducing phosphate absorption and lowering serum phosphate.

Prescribing in practice

• It must be taken with meals to bind dietary phosphate; the principal risk is hypercalcaemia, so the overall calcium load must be limited to avoid vascular calcification.
• Avoid in hypercalcaemia and use cautiously where calcium intake from all sources is already high, switching to a non-calcium binder if hypercalcaemia develops.
• Separate administration from oral medicines whose absorption it reduces, including certain antibiotics, iron, levothyroxine and bisphosphonates.

Monitoring

Monitor serum calcium and phosphate regularly to maintain phosphate control while avoiding hypercalcaemia.

Counselling the patient

• Take it with or just before food so it can soak up the phosphate in your meal.
• Keep separate from other tablets such as some antibiotics, iron and thyroid medicine.
• Report symptoms of a high calcium level such as nausea, constipation or confusion.

Evidence & guidelines

Phosphate binder use and calcium-balance considerations in CKD are guided by KDIGO and NICE CKD mineral and bone disorder recommendations.