calcium acetate

Binds to dietary phosphate to form an insoluble calcium phosphate complex, which is excreted in the feces, resulting in decreased serum phosphorus concentrations.

Therapeutic effects:

Control of hyperphosphatemia in end-stage renal disease without promoting aluminum absorption.

Pharmacokinetics ⬆ ⬇

Absorption: Absorption from the GI tract requires vitamin D; 30–40% bioavailability.

Distribution: Readily enters extracellular fluid. Crosses the placenta and enters breast milk.

Metabolism/Excretion: Excreted mostly in the feces; 20% eliminated by the kidneys.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(effects on serum calcium)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	unknown	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypercalcemia;
Renal calculi;
Ventricular fibrillation;
Concurrent use of calcium supplements.

Use Cautiously in:

Patients receiving digitalis glycosides;
Severe respiratory insufficiency;
Renal disease;
Cardiac disease;
OB: Hypercalcemia may ↑ risk of maternal and fetal complications;
Lactation: Breastfeeding not expected to harm infant provided that serum calcium levels monitored.

Adv. Reactions/Side Effects ⬆ ⬇

CV: arrhythmias, bradycardia

F and E: hypercalcemia

GI: constipation, nausea, vomiting

GU: calculi, hypercalciuria

Neuro: headache, tingling

Interactions ⬆ ⬇

Drug-drug:

Hypercalcemia ↑ risk of digoxin toxicity.
Chronic use with antacids in renal impairment may lead to milk-alkali syndrome.
Calcium supplements, including calcium-containing antacids may ↑ risk of hypercalcemia; avoid concurrent use.
May ↓ absorption of orally administered phenytoin and iron salts; take 1 hr before or 3 hr after calcium acetate.
May ↓ absorption of orally administered tetracyclines; take ≥1 hr before calcium acetate
May ↓ absorption of orally administered fluoroquinolones; take ≥2 hr before or 6 hr after calcium acetate
May ↓ absorption of orally administered levothyroxine; take ≥4 hr before or 4 hr after calcium acetate
Excessive amounts may ↓ effects of calcium channel blockers.
↓absorption of etidronate and risedronate (do not take within 2 hr of calcium acetate).
May ↓ effectiveness of atenolol.
Concurrent use with diuretics (thiazide) may result in hypercalcemia.
May ↓ ability of sodium polystyrene sulfonate to ↓ serum potassium.

Drug-Food:

Cereals, spinach, or rhubarb may ↓ absorption of calcium supplements.

Route/Dosage ⬆ ⬇

1 gram of calcium acetate contains 250 mg elemental calcium (12.7 mEq calcium). Doses are expressed in mg calcium acetate
PO (Adults ): Hyperphosphatemia in end-stage renal disease—1334 mg with each meal, may ↑ gradually (in absence of hypercalcemia) to achieve target serum phosphate levels (usual dose = 2001–2668 mg with each meal).

Availability ⬆ ⬇

(Generic available)

Gelcaps: 667 mg (169 mg elemental Ca)
Tablets: 667 mg (169 mg elemental Ca)

Assessment ⬆ ⬇

Monitor patient on digitalis glycosides for signs of toxicity.

Lab Test Considerations:

Monitor serum calcium twice weekly during adjustment phase. If serum calcium level is >12 mg/dL, discontinue therapy and start hemodialysis as needed; lower dose or temporarily stop therapy for calcium level between 10.5 to 11.9 mg/dL.
- Monitor serum phosphate levels to determine efficacy.

Implementation ⬆ ⬇

PO: Administer on an empty stomach before meals to optimize effectiveness in patients with hyperphosphatemia.

Patient/Family Teaching ⬆ ⬇

Advise patient to avoid taking calcium-containing supplements, including calcium-based antacids during therapy.
Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

Instruct patients on taking calcium acetate on a regular schedule to take missed doses as soon as possible, then go back to regular schedule.
Instruct patient in foods to avoid on a low calcium diet. See Food Sources for Specific Nutrients.
Advise patient to notify health care professional promptly if signs and symptoms of hypercalcemia (constipation, anorexia, nausea, vomiting, confusion, stupor) occur.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇