calcium acetate

Medically Reviewed on 11/30/2022

Generic Name: calcium acetate

Brand Names: PhosLoPhoslyra,

Drug Class: Calcium Salts; PO4 Scavengers; Urea Cycle Disorder Treatment Agents

What is calcium acetate, and what is it used for?

Calcium acetate is a medication used to reduce blood phosphate levels (hyperphosphatemia), a complication associated with advanced kidney disease. Patients with end-stage renal disease are prone to phosphate retention, which causes secondary hyperparathyroidism, leading to renal osteodystrophy, a bone disease, and calcification of soft tissue.

Treatment for hyperphosphatemia includes a reduction in dietary intake of phosphate and removal of phosphate with efficient dialysis methods. In addition, calcium acetate is used to eliminate any phosphate absorbed from food. When taken with meals, calcium acetate binds to dietary phosphate to form insoluble calcium phosphate that cannot be absorbed by the body, which is then excreted in the stools.


  • Do not use calcium acetate in patients with:
  • Calcium acetate can cause gas, bloating and constipation.
  • Use with caution in patients who are at risk for irregular heart rhythms or those taking digitalis, calcium acetate may precipitate arrhythmia.
  • Treatment with calcium acetate can cause hypercalcemia in patients with end-stage renal disease. Avoid concurrent use of calcium supplements.
  • Monitor calcium levels twice weekly, in the early phase of treatment and when adjusting dosage, because overdosing may lead to progressive hypercalcemia. If the patient develops hypercalcemia, reduce dosage or discontinue calcium acetate, depending on the severity. In addition, decrease or discontinue any concomitant vitamin D therapy.
  • Chronic hypercalcemia can lead to calcification of soft tissue and blood vessels.
  • Advise patients to reduce intake of oxalate-rich foods to avoid calcium-oxalate formation.
  • Calcium administration interferes with the absorption of some minerals and drugs, use with caution.
  • Oral solution contains maltitol, a sugar substitute, which may have a laxative effect.
  • Some formulations may contain propylene glycol which can be toxic in large amounts.

What are the side effects of calcium acetate?

Common side effects of calcium acetate include:

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.


The only purpose of the kidneys is to filter blood. See Answer

What are the dosages of calcium acetate?


  • 667 mg (169 mg elemental Ca)

Oral Solution

  • 667 mg/5 mL (169 mg/5 mL elemental Ca)


Hyperphosphatemia in End Stage Renal Failure (On Dialysis)

  • Initial: 2 capsules (1334 mg) orally with each meal
  • Increase dose to bring serum phosphate value below 6 mg/dL as long as hypercalcemia does not develop
  • Usual Dose: 3-4 capsules (2001-2868 mg) orally with each meal

Other Information


  • Safety and efficacy not established


  • Overdose of calcium acetate can increase blood calcium levels excessively and lead to hypercalcemia. Symptoms of mild hypercalcemia include nausea, vomiting, loss of appetite and constipation, while severe hypercalcemia can cause confusion, full or partial loss of consciousness and incoherent speech.
  • Treatment of calcium acetate overdose includes discontinuation of calcium acetate and measures to eliminate excess calcium from the blood by increasing excretion in urine, or with hemodialysis in patients with heart failure or kidney insufficiency.

What drugs interact with calcium acetate?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

  • Severe interactions of calcium acetate include:
    • ceftriaxone
  • Serious interactions of calcium acetate include:
  • Calcium acetate has moderate interactions with at least 54 different drugs.
  • Calcium acetate has mild interactions with at least 5o different drugs.

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider about all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or healthcare provider if you have any questions about the medication.

Pregnancy and breastfeeding

  • There are no animal reproductive studies or adequate and well-controlled studies of calcium acetate use in pregnant women.
  • Calcium acetate treatment as recommended is not expected to harm the fetus if maternal calcium levels are monitored and maintained at normal levels during and after the treatment.
  • Hypercalcemia during pregnancy can increase the risks for complications such as stillbirth, preterm delivery, and neonatal hypocalcemia and hypoparathyroidism.
  • Calcium acetate is excreted in breast milk, however, it is not expected to harm the breastfed infant if normal calcium levels are maintained in the nursing mother.

What else should I know about calcium acetate?

  • Take calcium acetate with meals exactly as prescribed.
  • Adhere to your prescribed diet and avoid oxalate rich foods such as soy, green leafy vegetables and animal protein.
  • Avoid taking calcium supplements including over-the-counter (OTC) antacids.
  • Inform your physician if you experience symptoms such as nausea, vomiting, constipation or loss of appetite.
  • Store safely out of reach of children.
  • In case of overdose, contact your physician or Poison Control.


Calcium acetate is a medication used to reduce blood phosphate levels (hyperphosphatemia), a complication associated with advanced kidney disease. Common side effects of calcium acetate include hypercalcemia, itching (pruritus), swelling (edema), dizziness, weakness, headache, low magnesium levels in blood (hypomagnesemia), low phosphate levels in blood (hypophosphatemia), irregular heart rhythm (arrhythmia), and low blood pressure (hypotension).

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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Medically Reviewed on 11/30/2022