Lanthanum (Fosrenol) was listed on the Pharmaceutical Benefits Scheme on 1 May 2009. The authority listing allows prescribing for the treatment of hyperphosphataemia in adults with chronic kidney disease who are on dialysis*, but not in combination with sevelamer.¹ Until this listing, lanthanum had been available only on private prescription.

Lanthanum is a rare earth element that reduces serum phosphate concentration by binding phosphate in the gut.^2,3 Calcium-based phosphate binders are first line for the treatment of hyperphosphataemia (unless serum calcium concentration is > 2.4 mmol/L).⁴ Lanthanum may be an alternative for people taking calcium carbonate (Caltrate, Cal-Sup), for whom hypercalcaemia is a problem.^2,4 Other available phosphate binders include aluminium hydroxide (Alu-tab), which is not PBS listed, and sevelamer (Renagel), which has the same PBS authority listing as lanthanum.⁵

Monitor serum phosphate concentrations every 2–3 weeks (adjust lanthanum dose as needed) until stable, then at regular intervals.^2,3 Although only a very small amount is absorbed, it is distributed into bone.³ Lanthanum often causes gastrointestinal adverse effects (e.g. nausea). As with any new drug, the full toxicity profile and long-term effects of lanthanum are unknown.

A 6-month unblinded randomised trial (n = 777) showed similar efficacy for lanthanum and calcium carbonate in reducing serum phosphate concentrations.⁶ This was maintained for those who remained in the extension trial: 46 people for 2.5 years⁷ and 22 people for 6 years.⁸ Another randomised unblinded trial (2 years, n = 1359) showed similar efficacy for lanthanum and other phosphate binders (including calcium [carbonate and acetate] and sevelamer).⁹

*Hyperphosphataemia in an adult with chronic kidney disease who is on dialysis and whose serum phosphate level is not controlled with other products and when:
(a) serum phosphate concentration is > 1.6 mmol/L, or
(b) the serum calcium (mmol/L) × phosphate (mmol/L) product is > 4.0 mmol²/L²

References

1. Pharmaceutical Benefits Advisory Committee. Positive recommendations made by the Pharmaceutical Benefits Advisory Committee (PBAC) in November 2008 relating to the listing of drugs on the Pharmaceutical Benefits Scheme (PBS). Canberra: Australian Government Department of Health and Ageing, 2008. http://www.carers.health.gov.au/internet/main/publishing.nsf/Content/pbacrec-nov08-positive (accessed 24 December 2008).
2. Rossi S, ed. Australian Medicines Handbook. Adelaide: Australian Medicines Handbook Pty Ltd, 2009.
3. Shire Australia Pty Limited. Fosrenol product information. 29 October 2008.
4. Caring for Australians with Renal Impairment (CARI). Use of phosphate binders in chronic kidney disease. The CARI Guidelines. Sydney: CARI, 2006. http://www.cari.org.au/CKD_bone_list_published/The_use_of_phosphate_binders_in_CKD.pdf (accessed 9 January 2009).
5. Department of Health and Ageing. PBS for Health Professionals. Canberra, 2008. http://www.pbs.gov.au (accessed 9 January 2009).
6. Hutchison AJ, Maes B, Vanwalleghem J, et al. Efficacy, tolerability and safety of lanthanum carbonate in hyperphosphataemia: a 6-month randomized comparative trial versus calcium carbonate. Nephron Clin Pract 2005;100:c8–19. [PubMed]
7. Hutchison AJ, Maes B, Vanwalleghem J, et al. Long-term efficacy and tolerability of lanthanum carbonate: results from a 3-year study. Nephron 2006;102:c61–71. [PubMed]
8. Hutchison AJ, Barnett ME, Krause R, et al. Long-term efficacy and safety profile of lanthanum carbonate: results for up to 6 years of treatment. Nephron Clin Pract 2008;110:c15–23. [PubMed]
9. Finn WF, on behalf of the S.P D. Lanthanum Study Group. Lanthanum carbonate versus standard therapy for the treatment of hyperphosphatemia: safety and efficacy in chronic maintenance hemodialysis patients. Clin Nephrol 2006;65:191–202. [PubMed]