Estimated Binding Power of MgCO3

Per K/DOQI figures, calculations are based on a 1000 mg P intake p/day. Additionally, per K/DOQI, we are also basing calculations on the average of 257 mg P needing to be bound p/day for hemodialysis patients and 285 mg P for peritoneal dialysis patients.

From Delmez et al: (Hemodialysis)

CaCO₃ Phase:	MgCO₃ Phase:
Phosphorous controlled with: 2.9 g Ca (7300 mg CaCO₃)	Phosphorous controlled with: 1.2 g Ca (3000 mg CaCO₃) and 465 mg Mg (1630 mg MgCO₃)
257/7.3= 35 mg P bound per 1 g of CaCO₃ (P remaining to be bound divided by salt weight)	3 X 35= 105 (P bound CaCO₃) (3000 mg CaCO3 X amt of P bound by 1 g CaCO₃ )
	257-105= 152 mg (P bound by MgCO₃) 152/1.63= 93.25 (P bound by MgCO3 divided by salt weight)
Note: K/DOQI states 39 mg P bound per 1 gram of CaCO₃	93.25 mg P bound per 1 g MgCO₃

Delmez JA, Kelber J, Norwood KY, Giles KS and Slatopolsky E: Magnesium Carbonate as a Phosphate Binder: A Prospective, Controlled, Crossover Study. Kidney Int., vol. 49, 163-167, 1996.

From Parsons et al: (Peritoneal Dialysis)

2200 mg CaCO₃ combined with 2200 mg MgCO₃ maintained P control in PD patients. 39* X 2.2= 85.8 mg (mg of P bound by CaCO₃ X salt weight of CaCO₃) 285 - 85.8= 199.2 (P remaining to be bound - P bound by CaCO₃= amount of P bound by MgCO₃) 199.2/2.2= 90.54 mg P bound by 1 g MgCO₃

*Based upon K/DOQI binding of CaCO₃

Parsons V, Baldwin D, Monitz C, Marsden J, Ball E, Rifkin I: Successful Control of Hyperparathyroidism in Patients on Continuous Ambulatory Peritoneal Dialysis Using Magnesium Carbonate and Calcium Carbonate as Phosphate Binders. Nephron 63: 379-383, 1993.

The theoretical binding capacity¹ for each tablet of MagneBind^® has been calculated by setting the binding capacity of MgCO₃ at 90 mg of P bound per 1 g of MgCO₃ and using 39 mg of P bound from 1 g of CaCO₃ as stated in K/DOQI.

MagneBind^® 200 ~33.6 mg P bound per tablet 257/33.6= 7.64 tablets p/day (HD) MagneBind^® 300 ~36.75 mg P bound per tablet 257/36.75= 6.99 tabletsp/day(HD) MagneBind^® 400 Rx ~43.8 mg P bound per tablet 257/43.8= 5.86 tablets p/day (HD)

¹ Usual dose for MagneBind^® 200 and MagneBind^® 300 is 9 tablets p/day. MagneBind^® 400 Rx is dosed 1-2 tablets TID as an adjunct to other binders, or as a the sole binder.