PhosLo (calcium acetate) is a prescription phosphate binder specifically formulated for the management of hyperphosphatemia in patients with end-stage renal disease (ESRD) who are on dialysis. By effectively binding dietary phosphate in the digestive tract, it prevents its absorption into the bloodstream, thereby helping to maintain crucial mineral balance. This targeted action is fundamental in mitigating the serious long-term complications associated with elevated serum phosphate levels, including renal osteodystrophy and vascular calcification. Its efficacy and established safety profile make it a cornerstone therapy in nephrology care protocols.

Features

• Active Pharmaceutical Ingredient: Calcium acetate (667 mg per tablet).
• Mechanism of Action: Binds with dietary phosphate in the intestine to form insoluble calcium phosphate, which is excreted in the feces.
• Formulation: Film-coated, oval-shaped tablets for oral administration.
• Proven Efficacy: Demonstrated in clinical studies to significantly reduce serum phosphorus and calcium-phosphorus product levels.
• Targeted Action: Works locally within the gastrointestinal tract with minimal systemic absorption.

Benefits

• Effectively lowers and helps maintain serum phosphate levels within the target range for dialysis patients.
• Reduces the risk of developing secondary hyperparathyroidism and associated bone disease (renal osteodystrophy).
• Helps prevent dangerous soft tissue and vascular calcification, a major contributor to cardiovascular morbidity.
• Provides a source of calcium, which can help manage hypocalcemia, though this requires careful monitoring.
• Supports overall mineral and bone disorder (CKD-MBD) management strategies as part of a comprehensive renal care plan.
• Offers a well-tolerated and predictable binding option to support long-term treatment adherence.

Common use

PhosLo is indicated for the control of hyperphosphatemia in patients with end-stage renal disease. It is used as an integral part of the therapeutic regimen for patients undergoing dialysis, working in conjunction with dietary phosphate restriction. Its primary function is to manage the elevated serum phosphate levels that the kidneys can no longer excrete, thereby addressing a key factor in the progression of chronic kidney disease-mineral and bone disorder (CKD-MBD).

Dosage and direction

The dosage of PhosLo must be individualized for each patient based on serum phosphate levels and is intended to be taken with meals. The initial typical adult dosage is two tablets with each meal. The dosage may be gradually increased to bring serum phosphate levels under control, up to a maximum of six tablets per meal, as directed by a physician. It is critical that the tablets are swallowed whole and not crushed or chewed. The dose should always be taken with meals to coincide with the intake of dietary phosphate for optimal binding efficacy.

Precautions

• Serum calcium levels must be monitored regularly throughout therapy to avoid hypercalcemia.
• Patients should be advised to adhere to a prescribed phosphate-restricted diet.
• Use with caution in patients with hypercalcemia or a history of calcium-related disorders.
• Not intended for use in patients with normal renal function or those not on dialysis.
• Caution is advised in patients who are also taking digitalis, as hypercalcemia can potentiate digitalis toxicity.

Contraindications

PhosLo is contraindicated in patients with hypercalcemia. It must not be used as a phosphate binder in patients who are not on dialysis or who have normal renal function.

Possible side effect

Like all medications, PhosLo can cause side effects, although not everybody gets them. Common side effects are primarily gastrointestinal and may include:

• Nausea
• Vomiting
• Loss of appetite
• Constipation
• Dry mouth Less common but more serious side effects related to elevated calcium levels (hypercalcemia) may occur and include:
• Confusion
• Lethargy
• Calcification of tissues and organs
• Irregular heartbeat

Drug interaction

PhosLo can interact with several other medications:

• Tetracycline antibiotics: PhosLo may decrease the absorption of tetracyclines (e.g., doxycycline, minocycline). Administer tetracyclines at least 1 hour before or 4 hours after PhosLo.
• Quinolone antibiotics: (e.g., ciprofloxacin, levofloxacin). PhosLo may impair absorption. Administer quinolones at least 2 hours before or 6 hours after PhosLo.
• Iron supplements: May have decreased absorption. Separate administration times.
• Thyroid hormones: (e.g., levothyroxine). PhosLo may decrease its absorption. Administer thyroid hormone at least 4 hours before PhosLo.
• Digoxin: Hypercalcemia from PhosLo may increase the risk of digitalis toxicity. Serum calcium and digoxin levels require close monitoring.

Missed dose

If a dose is missed, it should be taken as soon as it is remembered with food. However, if it is almost time for the next scheduled dose, the missed dose should be skipped. Patients should never take a double dose to make up for a forgotten one. It is important to maintain the regular dosing schedule with meals.

Overdose

Overdose of PhosLo may lead to severe hypercalcemia. Symptoms of hypercalcemia include nausea, vomiting, loss of appetite, constipation, dry mouth, thirst, confusion, lethargy, and in severe cases, coma. Treatment involves standard supportive measures and discontinuation of PhosLo. In severe cases, dialysis against a calcium-free dialysate can be employed to correct hypercalcemia.

Storage

Store PhosLo tablets at room temperature between 20°C to 25°C (68°F to 77°F). Keep the bottle tightly closed and stored in its original container to protect from moisture and light. Keep all medications out of the reach of children and pets. Do not use after the expiration date printed on the bottle.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read here. The information provided is based on the drug’s prescribing information but may not be all-inclusive.

Reviews

“PhosLo has been a reliable agent in my nephrology practice for years. Its predictable phosphate-binding efficacy and dual role in calcium supplementation, when monitored appropriately, make it a valuable tool in managing CKD-MBD.” – Dr. A. Reynolds, Nephrologist “As a dialysis nurse for over a decade, I’ve seen PhosLo help numerous patients achieve and maintain their phosphate goals. The dosing is straightforward, and most patients tolerate it well when taken correctly with meals.” – M. Thompson, RN “After starting dialysis, my phosphate levels were a constant struggle. Since my doctor prescribed PhosLo and I changed my diet, my levels have been consistently within range. It’s made a significant difference in my overall management.” – Patient K.L.