Calcium%25252520acetate

# Calcium Acetate ## Overview Calcium acetate is a phosphate binder used primarily in patients with end-stage renal disease (ESRD). It is highly soluble and binds dietary phosphate in the gastrointestinal tract to form insoluble calcium phosphate, which is then excreted in the feces. ## Primary Indications * Reduction of serum phosphorus in patients with end-stage renal disease. ## Adult Dosing * **Initial Dose:** 2 capsules or 667 mg tablets with each meal. * **Titration:** Adjust based on serum phosphate levels to achieve target goal (typically < 5.5 mg/dL). Doses are frequently titrated up to 3 to 4 capsules/tablets per meal depending on the phosphate content of the diet. * **Maximum Dose:** Generally avoid exceeding 1,500 mg of elemental calcium per day from all sources to minimize the risk of hypercalcemia. ## Pediatric Dosing Safety and efficacy have not been established in pediatric patients. Use is off-label and requires nephrology consultation. Dosing is typically weight-based or extrapolated from adult data, often starting at 333–667 mg per meal. ## Dose Adjustments * **Renal Impairment:** No dose adjustment necessary for dialysis patients; however, hypercalcemia may necessitate a reduction in dose or a switch to a non-calcium-based phosphate binder (e.g., sevelamer or lanthanum). * **Hypercalcemia:** Hold dose if serum calcium exceeds 10.5 mg/dL. ## Contraindications * Hypercalcemia. * Hypophosphatemia. * Severe renal calculi (nephrolithiasis). ## Adverse Effects * **Common:** Hypercalcemia, constipation, nausea, vomiting, abdominal pain. * **Serious:** Metastatic calcification (due to elevated calcium-phosphorus product), hypercalcemia-related cardiac arrhythmias. ## Key Drug Interactions * **Fluoroquinolones/Tetracyclines:** Reduced absorption; administer these antibiotics at least 2 hours before or 6 hours after calcium acetate. * **Levothyroxine:** Reduced absorption; separate dosing by at least 4 hours. * **Bisphosphonates:** Reduced absorption; separate by at least 2 hours. * **Vitamin D:** Concurrent use increases calcium absorption and risk of hypercalcemia. ## Monitoring * **Serum Phosphorus:** Weekly during initial titration, then at least monthly. * **Serum Calcium:** Weekly during initial titration, then at least monthly. * **Calcium-Phosphorus Product:** Keep < 55 mg²/dL² to minimize risk of vascular calcification. ## Clinical Pearls * **Timing:** Must be taken with meals to be effective as a phosphate binder. * **Calcium Content:** Each 667 mg capsule/tablet provides 169 mg (8.4 mEq) of elemental calcium. * **Administration:** If the patient misses a meal, the dose should be skipped. * **Hypercalcemia Risk:** Monitor closely if the patient is also taking vitamin D analogs or high-calcium dialysate, as these increase the risk of hypercalcemia. *** **Educational Disclaimer:** This information is for educational purposes and does not replace professional clinical judgment. Always verify current prescribing information, institutional protocols, and patient-specific factors before administering medication.