What is the Difference Between Calcium Acetate and Calcium Carbonate?

Calcium acetate and calcium carbonate are two widely used phosphate-binding agents that help control serum phosphorus levels in patients with kidney disease, particularly those undergoing hemodialysis. Although both agents have similar efficacy, there are some differences between them:

1. Elemental Calcium Content: Calcium acetate contains less elemental calcium (325 mg) compared to calcium carbonate (500 mg).
2. Hypercalcemia: Calcium acetate has been shown to result in less frequency of hypercalcemia compared to calcium carbonate, although the incidence of hypercalcemia is similar during treatment periods.
3. Tolerance: Both drugs are generally well-tolerated, but patients more frequently complain of muscle cramps while taking calcium acetate. There is a higher incidence of intolerance with calcium acetate treatment, but the side effects are mild and easy to treat.
4. Phosphate Binding Power: In vitro and in vivo studies have shown that calcium acetate is more effective at binding phosphate than calcium carbonate, allowing for better control of serum phosphorus levels with a lower dose.
5. Calcium Absorption: Less calcium seems to be absorbed when calcium acetate is used, which could potentially reduce the incidence of hypercalcemia.

In conclusion, while both calcium acetate and calcium carbonate are effective phosphate-binding agents, calcium acetate has some advantages in terms of reduced hypercalcemia and increased phosphate-binding efficiency. However, it also has a higher incidence of intolerance, particularly muscle cramps.

Comparative Table: Calcium Acetate vs Calcium Carbonate

Here is a table comparing the differences between calcium acetate and calcium carbonate:

Both calcium acetate and calcium carbonate are used as phosphate-binding agents, but calcium acetate has been shown to be more effective in binding phosphorus and reducing the frequency of hypercalcemic events compared to calcium carbonate. However, calcium acetate has a higher incidence of intolerance compared to calcium carbonate.