PhosLo

Generic name: calcium acetate
Brand names: Calphron, PhosLo, Phoslyra
Drug classes: Minerals and electrolytes, Phosphate binders

Medically reviewed by A Ras MD.

What is PhosLo used for?

PhosLo is a prescription medicine that is used to lower high phosphate levels.

Description

PhosLo® acts as a phosphate binder. Its chemical name is calcium acetate. Its molecular formula is C 4H 6CaO 4, and its molecular weight is 158.17. Its structural formula is:

Each opaque gelcap with a blue cap and white body is spin printed in blue and white ink with “PhosLo®” printed on the cap and “667 mg” printed on the body. Each gelcap contains 667 mg calcium acetate, USP (anhydrous; Ca(CH 3COO) 2; MW=158.17 grams) equal to 169 mg (8.45 mEq) calcium, and 10 mg of the inert binder, polyethylene glycol 8000 NF. The gelatin cap and body have the following inactive ingredients: FD&C blue #1, D&C red #28, titanium dioxide, USP and gelatin, USP.

MECHANISM OF ACTION

Calcium acetate, (PhosLo®) 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.

Before taking PhosLo, tell your doctor:

If you are allergic to PhosLo; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
If you have high calcium levels.

This is not a list of all drugs or health problems that interact with this medicine.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take PhosLo with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take PhosLo?

Tell all of your health care providers that you take PhosLo. This includes your doctors, nurses, pharmacists, and dentists.
Have blood work checked as you have been told by the doctor. Talk with the doctor.
Do not take calcium or products that have calcium, like antacids, while you are taking PhosLo.
Some other drugs may need to be taken at some other time than PhosLo. If you take other drugs, check with your doctor or pharmacist to see if you need to take them at some other time than PhosLo.
Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

How is PhosLo best taken?

Use PhosLo as ordered by your doctor. Read all information given to you. Follow all instructions closely.

Take with meals.
Follow the diet plan that your doctor told you about.
Do not chew PhosLo.

What do I do if I miss a dose?

Take a missed dose as soon as you think about it.
If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
Do not take 2 doses at the same time or extra doses.

What are the side effects of PhosLo that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Signs of high calcium levels like weakness, confusion, feeling tired, headache, upset stomach and throwing up, constipation, or bone pain.

What are some other side effects of PhosLo?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

Upset stomach.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out PhosLo?

Store at room temperature in a dry place. Do not store in a bathroom.
Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.