Conciphos

Conciphos

Indications & Usage

Calcium Acetate Tablets are a phosphate binder indicated to reduce serum phosphorus in patients with end stage renal disease (ESRD).

Dosage & Administration

The recommended initial dose of calcium acetate tablets for the adult dialysis patient is 2 tablets with each meal. Increase the dose gradually to lower serum phosphorus levels to the target range, as long as hypercalcemia does not develop. Most patients require 3 to 4 tablets with each meal.

Dosage forms & Strengths

Tablets: 667 mg calcium acetate tablets.

Contraindications

Patients with hypercalcemia.

Warnings & Precautions :

Hypercalcemia
Patients with end stage renal disease may develop hypercalcemia when treated with calcium, including calcium acetate. Avoid the use of calcium supplements, including calcium based nonprescription antacids, concurrently with calcium acetate. An overdose of calcium acetate may lead to progressive hypercalcemia, which may require emergency measures. Therefore, early in the treatment phase during the dosage adjustment period, monitor serum calcium levels twice weekly. Should hypercalcemia develop, reduce the calcium acetate dosage, or discontinue the treatment, depending on the severity of hypercalcemia. More severe hypercalcemia (Ca >12 mg/dL) is associated with confusion, delirium, stupor and coma. Severe hypercalcemia can be treated by acute hemodialysis and discontinuing calcium acetate therapy. Mild hypercalcemia (10.5 to 11.9 mg/dL) may be asymptomatic or manifest as constipation, anorexia, nausea, and vomiting. Mild hypercalcemia is usually controlled by reducing the calcium acetate dose or temporarily discontinuing therapy. Decreasing or discontinuing Vitamin D therapy is recommended as well. Chronic hypercalcemia may lead to vascular calcification and other soft-tissue calcification. Radiographic evaluation of suspected anatomical regions may be helpful in early detection of soft tissue calcification. The long term effect of calcium acetate on the progression of vascular or soft tissue calcification has not been determined. Hypercalcemia (>11 mg/dL) was reported in 16% of patients in a 3 month study of solid dose formulation of calcium acetate; all cases resolved upon lowering the dose or discontinuing treatment. Maintain the serum calcium-phosphorus (Ca x P) product below 55 mg2/dL2.

Concomitant Use with Medications
Hypercalcemia may aggravate digitalis toxicity.

Adverse Reactions

Patients with end stage renal disease may develop hypercalcemia when treated with calcium, including calcium acetate. Avoid the use of calcium supplements, including calcium based nonprescription antacids, concurrently with calcium acetate.

Drug Interactions

The drug interaction of calcium acetate is characterized by the potential of calcium to bind to drugs with anionic functions (e.g., carboxyl, and hydroxyl groups). Calcium acetate may decrease the bioavailability of tetracyclines or fluoroquinolones via this mechanism. There are no empirical data on avoiding drug interactions between calcium acetate and most concomitant drugs. When administering an oral medication with calcium acetate where a reduction in the bioavailability of that medication would have a clinically significant effect on its safety or efficacy, administer the drug one hour before or three hours after calcium acetate. Monitor blood levels of the concomitant drugs that have a narrow therapeutic range. Patients taking anti-arrhythmic medications for the control of arrhythmias and anti-seizure medications for the control of seizure disorders were excluded from the clinical trials with all forms of calcium acetate.

Ciprofloxacin

In a study of 15 healthy subjects, a co-administered single dose of 4 calcium acetate tablets, approximately 2.7g, decreased the bioavailability of ciprofloxacin by approximately 50%.

Use in Specific Populations

Pregnancy

Pregnancy Category C
Calcium Acetate Capsules contains calcium acetate. Animal reproduction studies have not been conducted with calcium acetate, and there are no adequate and well controlled studies of calcium acetate use in pregnant women. Patients with end stage renal disease may develop hypercalcemia with calcium acetate treatment.Maintenance of normal serum calcium levels is important for maternal and fetal well being. Hypercalcemia during pregnancy may increase the risk for maternal and neonatal complications such as stillbirth, preterm delivery, and neonatal hypocalcemia and hypoparathyroidism. Calcium acetate treatment, as recommended, is not expected to harm a fetus if maternal calcium levels are properly monitored during and following treatment.

Labor and Delivery
The effects of calcium acetate on labor and delivery are unknown.

Nursing Mothers
Calcium Acetate Tablets contains calcium acetate and is excreted in human milk. Human milk feeding by a mother receiving calcium acetate is not expected to harm an infant, provided maternal serum calcium levels are appropriately monitored.

Pediatric Use
Safety and effectiveness in pediatric patients have not been established.

Geriatric Use
Clinical studies of calcium acetate did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other clinical experience has not identified differences in responses between elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Overdosage

Administration of Calcium Acetate Tablets in excess of the appropriate daily dosage may result in hypercalcemia.

Description

Calcium Acetate Tablets acts as a phosphate binder. Its chemical name is calcium acetate. Its molecular formula is C4H6CaO4, and its molecular weight is 158.17. Its structural formula is:

Each tablet contains 667 mg of calcium acetate, USP (anhydrous; Ca(CH3COO)2; MW=158.17 grams) equal to 169 mg (8.45 mEq) calcium. Calcium Acetate Capsules are administered orally for the control of hyperphosphatemia in end-stage renal failure.

Clinical Pharmacology
Patients with ESRD retain phosphorus and can develop hyperphosphatemia. High serum phosphorus can precipitate serum calcium resulting in ectopic calcification. Hyperphosphatemia also plays a role in the development of secondary hyperparathyroidism in patients with ESRD.

Mechanism of Action
Calcium acetate, when taken with meals, combines with dietary phosphate to form an insoluble calcium phosphate complex, which is excreted in the feces, resulting in decreased serum phosphorus concentration.

Pharmacodynamics
Orally administered calcium acetate from pharmaceutical dosage forms is systemically absorbed up to approximately 40% under fasting conditions and up to approximately 30% under nonfasting conditions. This range represents data from both healthy subjects and renal dialysis patients under various conditions.

Storage
Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature.]