Supply issue: calcium polystyrene sulphonate (Calcium Resonium)
- admin82291
- 2 days ago
- 1 min read

Kia ora
Supply issue:
We are writing to inform you of a supply issue. Due to a delay with manufacturing the supplier of calcium polystyrene sulphonate (Calcium Resonium), has advised it anticipates an out of stock between late-February and May 2026.
Key Date:
An alternative product Calcium polystyrene sulphonate Powder, (Roma brand) will be funded from 1 February 2026, under Section 29A of the Medicines Act.
Key Differences:
Both products are the same strength, however the strength is expressed differently:
The new product is labelled 99.934 % w/w with each 100g of powder containing 99.934g of calcium polystyrene sulfonate
The current product is labelled 999.3 mg/g with each 15g of powder containing calcium polystyrene sulfonate 14.99g
Preparation of the alternate Roma product: The suspension should be prepared immediately before use.
Preparation of the current Calcium Resonium product: Suspensions of the resin should be freshly prepared and not stored beyond 24 hours.
More information is available - Calcium polystyrene sulphonate Powder on Pharmac website.
Thank you for your support managing this supply issue, please reassure patients the strength of this medicine remains the same.
Questions:
If you have any queries, please contact us at enquiry@pharmac.govt.nz
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Ngā mihi,
Anna I Senior Advisor Implementation
Pharmac | Te Pātaka Whaioranga | PO Box 10 254 | Level 9, 40 Mercer Street, Wellington
P: 0800 660 050 | www.pharmac.govt.nz
