Calcium Acetate + Magnesium Carbonate

Calcium Acetate + Magnesium Carbonate is a combination tablet used for hyperphosphatemia in chronic renal insufficiency patients undergoing dialysis. Each film-coated tablet contains Calcium Acetate 435 mg (equivalent to 110 mg calcium) and Magnesium Carbonate 235 mg (equivalent to 60 mg magnesium).

Calcium Acetate and Magnesium Carbonate are phosphate-binding compounds. They form low solubility calcium and magnesium phosphate salts with dietary phosphate in the gut, which are excreted with feces. Calcium Acetate reaches its maximal phosphate-binding capacity at pH 6-8, making it suitable for patients with hypo- or anacidity of the stomach.

• Hyperphosphatemia in chronic renal insufficiency (patients undergoing dialysis)

Adults: 3-10 film-coated tablets per day, depending on serum phosphate levels. The daily dose should be subdivided according to the number of meals (usually 3 meals per day). Recommended starting dose: 3 tablets daily. If necessary, the dosage may be increased to a maximum of 12 film-coated tablets per day.

Children and adolescents (under 18 years): Safety and efficacy have not been established; not recommended.

Administration: Take with meals for maximum phosphate binding effect; do not crush or chew. Swallow with some liquid. If the tablet is too large, break along the score line before swallowing. Other oral medications should be taken 2 hours before or 3 hours after this tablet.

Gastrointestinal: Soft stools, gastrointestinal irritation (nausea, anorexia, sensation of fullness, belching, constipation, diarrhea) - Common.

Metabolism and nutrition: Hypercalcemia (asymptomatic or symptomatic) - Common; asymptomatic hypermagnesemia - Common; moderate to severe symptomatic hypercalcemia, symptomatic hypermagnesemia - Uncommon; hyperkalemia, magnesium-induced osteal mineralization disturbances - Very rare.

• Administer with caution (continuous monitoring of serum calcium, magnesium, and phosphate) in severe hyperphosphatemia with calcium-phosphate product >5.3 mmol/L refractory to therapy, refractory hyperkalemia, clinically relevant bradycardia or AV-block II° with bradycardia.
• Continuous monitoring of serum phosphate, magnesium, calcium, and calcium-phosphate product is required, especially with concomitant vitamin D preparations and thiazide diuretics.
• High doses and long-term administration may result in hypermagnesemia (mostly asymptomatic, but systemic effects may occur).
• Caution with antacids and digitalis glycosides.
• Patients with chronic renal insufficiency may develop hypercalcemic episodes, especially in combination with vitamin D metabolites.
• Monitor progression/appearance of vascular and soft tissue calcifications (reduce risk by keeping calcium-phosphate product <4.5 mmol/L).
• Reduce dose in case of diarrhea.

• Hypophosphatemia
• Hypercalcemia (with or without clinical symptoms) - e.g., vitamin D overdose, paraneoplastic syndrome (bronchial carcinoma, breast cancer, renal cell carcinoma, plasmacytoma), bone metastases, sarcoidosis, or immobilization osteoporosis
• Serum magnesium >2 mmol/L and/or symptoms of hypermagnesemia
• AV-block III°
• Myasthenia gravis
• Hypersensitivity to active substances or any excipients

• Tetracyclines, doxycycline, norfloxacin, ciprofloxacin, some cephalosporins (cefpodoxime, cefuroxime), bisphosphonates, fluorides, ketoconazole, estramustin, anticholinergics, iron supplements, digoxin, nitrofurantoin, levothyroxine: Absorption may be affected when coadministered; take 2 hours before or 3 hours after this tablet.
• Vitamin D and derivatives, thiazide diuretics, estrogens: May affect calcium absorption.
• Glycosides: Increased sensitivity and risk of arrhythmia with elevated serum calcium levels.
• Adrenaline: May cause severe arrhythmia in patients with elevated serum calcium.
• Calcium antagonists: Effect may be reduced.

Acute hypermagnesemia: Serum concentration 2.5 mmol/L: systemic toxicity; 3 mmol/L and above: severe neurotoxic effects. 2.5-5.0 mmol/L: gastrointestinal disturbances (nausea, anorexia, constipation), cystospasm, muscle weakness, lethargy, absent deep-tendon reflexes, disturbed AV-conduction and ventricular stimulus conduction. 5-10 mmol/L: vasodilation-induced arterial hypotension, paralytic ileus, flaccid paralysis, coma. >10 mmol/L: respiratory and cardiac arrest.

Hypercalcemia: Initial: muscle weakness, abdominal pain, constipation, nausea, vomiting. Severe: consciousness disturbances (lethargy, disorientation, stupor, coma). >3.5 mmol/L: polyuria, polydipsia, nausea, anorexia, constipation, pancreatitis (infrequent), arrhythmia, shortened QT-interval, adynamia, hypertension, muscle weakness up to pseudo-paralysis, psychosis, somnolence up to coma.

Emergency treatment: Hypermagnesemia: reduce magnesium concentration of dialysate and reduce dose. Hypercalcemia: calcium-free dialysate, close monitoring of serum calcium.