Please check your internet connection and try again.
# Calcium Acetate
## Overview
Calcium acetate is a phosphate binder used to manage hyperphosphatemia in patients with end-stage renal disease (ESRD). It is more calcium-dense than calcium carbonate and functions by binding dietary phosphate in the GI tract to form insoluble calcium phosphate, which is then excreted in feces.
## Primary Indications
Hyperphosphatemia in patients on chronic dialysis (hemodialysis or peritoneal dialysis).
## Adult Dosing
* **Initial Dose:** 2 capsules or 1,334 mg (two 667 mg tablets/capsules) orally with each meal.
* **Titration:** Adjust based on serum phosphate levels.
* **Maximum:** Dosing is often titrated to keep serum phosphate $<5.5$ mg/dL; however, clinical guidelines suggest limiting total daily elemental calcium intake (from binders and diet) to avoid hypercalcemia.
## Pediatric Dosing
Safety and efficacy in pediatric patients have not been established by the FDA. Dosing is off-label and varies significantly by institution; strictly follow local pediatric nephrology protocols. Generally involves milligrams per meal adjusted by serum phosphate response.
## Dose Adjustments
* **Hepatic/Renal Impairment:** No specific adjustments, but patients with chronic kidney disease require close monitoring of serum calcium and phosphate to prevent hypercalcemia or metastatic calcification.
## Contraindications
* Hypercalcemia.
* Hypophosphatemia.
* Hypersensitivity to calcium acetate.
## Adverse Effects
* **Common:** Hypercalcemia, nausea, vomiting, constipation, abdominal pain.
* **Serious:** Metastatic calcification (soft tissue/vascular), severe hypercalcemia, metabolic alkalosis.
## Key Drug Interactions
* **Fluoroquinolones/Tetracyclines:** Calcium significantly decreases absorption. Must administer these antibiotics at least 2 hours before or 6 hours after calcium acetate.
* **Bisphosphonates:** Calcium reduces oral absorption; separate doses by at least 2 hours.
* **Levothyroxine:** Calcium interferes with absorption; separate by at least 4 hours.
* **Iron Salts:** Calcium may decrease iron absorption; separate dosing.
## Monitoring
* **Serum Calcium:** Monitor weekly during initiation and dose titration; monthly thereafter.
* **Serum Phosphate:** Monitor at least monthly.
* **Calcium-Phosphate Product:** Maintain product $<55$ mg²/dL² to minimize risk of vascular calcification.
* **Hypercalcemia Symptoms:** Watch for confusion, delirium, constipation, or cardiac arrhythmias.
## Clinical Pearls
* **Timing:** Must be taken **with meals** to effectively bind dietary phosphate. Taking it without food provides minimal phosphate-binding benefit and increases the systemic absorption of calcium.
* **Calcium Content:** Each 667 mg capsule/tablet contains 169 mg (8.45 mEq) of elemental calcium.
* **Alternative Binders:** If hypercalcemia develops, consider switching to a non-calcium-based binder such as sevelamer or lanthanum.
***
**Disclaimer:** This information is for educational purposes for healthcare professionals. Dosages may vary based on local clinical protocols, patient-specific factors, and institutional policies. Always verify the current prescribing information and clinical guidelines before prescribing or administering medication.
