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PHOSLYRA acts as a phosphate binder. Its chemical name is calcium acetate. Its molecular formula is C4H6CaO4, and its molecular weight is 158.17.

PHOSLYRA for oral administration is provided as pale to light greenish-yellow clear liquid. Each 5 mL of PHOSLYRA contains 667 mg calcium acetate, USP equal to 169 mg (8.45 mEq) calcium. PHOSLYRA also contains the following inactive ingredients: maltitol NF, glycerin USP, Magnasweet 110, propylene glycol USP, povidone K25 USP, sucralose NF, methylparaben NF, artificial black cherry flavor, menthol flavor, purified water USP.

Clinical pharmacology

Patients with ESRD retain phosphorus and can develop hyperphosphatemia. High serum phosphorus can precipitate serum calcium resulting in ectopic calcification. Hyperphosphatemia also plays a role in the development of secondary hyperparathyroidism in patients with ESRD.

Mechanism of Action
Calcium acetate, 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 concentrations.

Indications and usage 

PHOSLYRA is a phosphate binder indicated for the reduction of serum phosphorus in patients with end stage renal disease.




Treat mild hypercalcemia by reducing or interrupting PHOSLYRA and Vitamin D. Severe hypercalcemia may require hemodialyis and discontinuation of PHOSLYRA.

May cause diarrhea with nutritional supplements that contain maltitol.

PHOSLYRA may decrease the bioavailability of tetracyclines or fluoroquinolones.
When clinically significant drug interactions are expected, administer the drug at least one hour before or at least three hours after PHOSLYRA, or consider monitoring blood levels of the drug.

Adverse reactions

 The most common (>10%) adverse reactions are hypercalcemia, nausea, and diarrhea.

To report SUSPECTED ADVERSE REACTIONS, contact Fresenius Medical Care North America at 1-800-323-5188 or FDA at 1-800-FDA-1088 or

Dosage and administration 

Starting dose is 10 mL with each meal.
Titrate the dose every 2 to 3 weeks until an acceptable serum phosphorus level is reached. Most patients require 15 to 20 mL with each meal.

How supplied

Oral Solution: 667 mg calcium acetate per 5 mL.


PHOSLYRA for oral administration is a clear solution containing 667 mg calcium acetate per 5 mL. PHOSLYRA is supplied in amber-colored, multiple-dose bottles, packaged with a marked dosing cup in the following size:

473 mL (16 fl. oz) bottle (NDC 49230-643-31)

Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [see USP Controlled Room Temperature].
The shelf life is 24 months.


Package Insert data: 
Manufactured for:
Fresenius Medical Care North America
Waltham, MA 02451

Manufactured by:
Lyne Laboratories
Brockton, MA 02301
101087.00 4/2011


National Institutes of Health, U.S. National Library of Medicine, DailyMed Database.
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