If a dialysis patient is taking the drug class calcimimetic, which laboratory value indicates that the drug is effective?

A reduction in serum calcium level is indicative of the effectiveness of calcimimetics. Calcimimetics, such as cinacalcet, are designed to enhance the sensitivity of calcium-sensing receptors in the parathyroid glands. This results in decreased secretion of parathyroid hormone (PTH) and, consequently, a reduction in serum calcium levels.

In patients receiving treatment for conditions like secondary hyperparathyroidism associated with chronic kidney disease, an effective response to calcimimetic treatment is often reflected in lower serum calcium. This effect is critical in managing calcium and phosphorus balance, especially as patients undergoing dialysis are at risk for imbalances due to impaired renal function.

The other laboratory values mentioned do not directly correlate with the efficacy of calcimimetics. While increased RBCs or decreased platelet count could indicate a variety of other conditions or responses, they are not specific to the actions of calcimimetics. Similarly, an increase in serum phosphorus would signal issues with phosphorus control, which is a separate concern in dialysis patients and not an indicator of the efficacy of calcimimetics.