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Calcium Acetate

(kal' see um as' e tate)

Brand Name(s): PhosLo®, Phoslyra®; also available generically

WHY is this medicine prescribed?

Calcium acetate is used to control high blood levels of phosphorus in people with kidney disease who are on dialysis (medical treatment to clean the blood when the kidneys are not working properly). Calcium acetate is in a class of medications called phosphate binders. It binds phosphorus that you get from foods in your diet and prevents it from being absorbed into your blood stream.

Are there OTHER USES for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

HOW should this medicine be used?

Calcium acetate comes as a capsule, tablet, and a solution (liquid) to take by mouth. It is usually taken along with each meal (e.g., 3 times a day if you eat 3 meals a day) as directed by your doctor. Take calcium acetate at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take calcium acetate exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you are using the solution, do not use a household spoon to measure your dose. Use the dosing cup that comes with the medication to measure your dose. Ask your pharmacist if you have any question about how much medication you should take or how to use the dosing cup.

Your doctor will probably adjust your dose based on your phosphorus blood levels, not more often than once every 2 to 3 weeks.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

What SPECIAL PRECAUTIONS should I follow?

Before taking calcium acetate,

  • tell your doctor and pharmacist if you are allergic to calcium acetate, any other medications, or any of the ingredients in calcium acetate preparations. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: digoxin (Lanoxin). Take a fluoroquinolone antibiotic such as ciprofloxacin (Cipro), gemifloxacin (Factive), levofloxacin, or moxifloxacin (Avelox) at least 2 hours before or 6 hours after taking calcium acetate. Also, take levothyroxine (Euthyrox, Synthroid, Tirosint) at least 4 hours before or 4 hours after taking calcium acetate. Take a tetracycline antibiotic such as demeclocycline, doxycycline (Monodox, Oracea, Vibramcyin), minocycline (Dynacin, Minocin, Solodyn), or tetracycline (Achromycin V, in Pylera) at least 1 hour before taking calcium acetate. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with calcium acetate, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • tell your doctor if you are taking calcium supplements or calcium antacids (Tums). Do not take supplements or antacids containing calcium while taking calcium acetate.
  • tell your doctor if you have high levels of calcium in the blood. Your doctor will probably tell you not to take calcium acetate.
  • tell your doctor if you have or have ever had any other medical conditions.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking calcium acetate, call your doctor.

What SPECIAL DIETARY instructions should I follow?

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Skip the missed dose and continue your regular dosing schedule with your next meal. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Calcium acetate may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • nausea
  • vomiting
  • constipation
  • loss of appetite
  • itching

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment:

  • confusion, feeling disoriented, feeling faint, or loss of consciousness

Calcium acetate may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

  • confusion
  • feeling disoriented
  • feeling faint
  • loss of consciousness

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests to check your body's response to calcium acetate.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists® represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists® makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists® does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

Pronunciation Guide for Drug Names is used with permission. © 2009. The United States Pharmacopeial Convention. All Rights Reserved.

AHFS® Patient Medication Information™. © Copyright, 2020. The American Society of Health-System Pharmacists®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: March 15, 2020.