Phoslo (calcium acetate) is a prescription phosphate binder indicated for the reduction of serum phosphorus in patients with end-stage renal disease. It works by binding dietary phosphate in the digestive tract, forming an insoluble complex that is excreted in feces, thereby preventing its absorption into the bloodstream. Proper management of hyperphosphatemia is critical in renal care to mitigate the risk of secondary hyperparathyroidism and vascular calcification. This medication represents a cornerstone therapy in nephrology for maintaining mineral and bone disorder parameters within target ranges.

Features

• Contains calcium acetate as the active pharmaceutical ingredient
• Available in 667 mg gelcaps and tablets for precise dosing
• Works specifically in the gastrointestinal tract without systemic absorption
• Formulated to maximize phosphate binding capacity per dose
• Manufactured under strict pharmaceutical quality standards

Benefits

• Effectively lowers serum phosphate levels in dialysis patients
• Helps reduce the risk of cardiovascular complications associated with hyperphosphatemia
• Supports management of renal osteodystrophy by controlling phosphorus accumulation
• May decrease the progression of vascular calcification
• Provides calcium supplementation which can benefit bone health
• Enables better overall mineral balance in chronic kidney disease patients

Common use

Phoslo is primarily prescribed for patients with end-stage renal disease who are on dialysis. It is used to control hyperphosphatemia (elevated phosphate levels in the blood), which commonly occurs when kidneys can no longer adequately excrete phosphorus. The medication is typically taken with meals to bind dietary phosphorus as it enters the digestive system. Nephrologists often prescribe Phoslo as part of a comprehensive renal management protocol that may include dietary phosphorus restriction, vitamin D analogs, and calcimimetics.

Dosage and direction

The initial dosage for Phoslo is typically 2 capsules (1334 mg) or tablets with each meal. Dosage should be individualized based on serum phosphorus levels and the phosphorus content of meals, with most patients requiring 3-4 capsules with each meal. The medication must be taken with meals to effectively bind dietary phosphorus. Tablets should be swallowed whole and not crushed or chewed. Dosage adjustments should be made in increments of 1-2 capsules per meal under medical supervision, with regular monitoring of serum calcium and phosphorus levels.

Precautions

Regular monitoring of serum calcium and phosphorus levels is essential during therapy. Patients should be cautioned about possible hypercalcemia (elevated calcium levels), especially those with conditions predisposing to hypercalcemia. Use with caution in patients with sarcoidosis or those taking digitalis preparations. Patients should maintain a phosphorus-restricted diet as prescribed. Calcium acetate may decrease the bioavailability of tetracycline antibiotics when taken concurrently. Periodic assessment of calcium-phosphate product is recommended to avoid metastatic calcification.

Contraindications

Phoslo is contraindicated in patients with hypercalcemia (serum calcium greater than 10.5 mg/dL). It should not be used in patients with known hypersensitivity to calcium acetate or any component of the formulation. The medication is contraindicated in patients with calcium-containing renal calculi. Use is not recommended in patients with hypophosphatemia or those with low intact parathyroid hormone (iPTH) levels without careful monitoring.

Possible side effects

Common side effects include hypercalcemia, which may manifest as nausea, vomiting, anorexia, constipation, and dry mouth. Less frequently, patients may experience diarrhea, abdominal discomfort, or pruritus. Serious side effects requiring medical attention include severe hypercalcemia (confusion, lethargy, coma), ectopic calcification, and milk-alkali syndrome. Metabolic alkalosis may occur with prolonged use. Some patients may experience localized tissue calcification with prolonged hypercalcemia.

Drug interaction

Phoslo may decrease the absorption of tetracycline antibiotics, quinolones, iron supplements, and thyroid medications when taken concurrently. Concomitant use with vitamin D supplements may increase the risk of hypercalcemia. Thiazide diuretics may potentiate hypercalcemia when used with calcium acetate. Calcium channel blockers may have their effects altered. Patients taking digitalis should be monitored carefully as hypercalcemia may potentiate digitalis toxicity. Administration should be separated by at least 2 hours from other medications to avoid binding interactions.

Missed dose

If a dose is missed, it should be taken as soon as remembered with food. However, if it is almost time for the next scheduled dose, the missed dose should be skipped. Patients should not double the dose to make up for a missed dose. Consistent dosing with meals is important for effective phosphate control. Patients should maintain their regular dosing schedule and consult their healthcare provider if multiple doses are missed.

Overdose

Overdose may lead to severe hypercalcemia, which can cause confusion, lethargy, coma, nausea, vomiting, anorexia, and constipation. In severe cases, metastatic calcification, arrhythmias, and renal impairment may occur. Treatment involves discontinuation of calcium acetate, a low-calcium diet, and hydration. Severe hypercalcemia may require loop diuretics, corticosteroids, calcitonin, or dialysis. Serum calcium levels should be monitored closely, and supportive care provided based on symptoms.

Storage

Store at room temperature between 20-25°C (68-77°F). Keep the container tightly closed and protect from moisture. Do not store in bathroom areas where humidity levels fluctuate. Keep out of reach of children and pets. Do not use if the packaging is damaged or if the product appears discolored or degraded. Proper disposal of unused medication should follow local regulations for pharmaceutical waste.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Phoslo is a prescription medication that should be used only under the supervision of a qualified healthcare provider. Dosage and treatment decisions should be made by a physician based on individual patient needs and laboratory parameters. Patients should not adjust their medication without consulting their healthcare provider. The manufacturer’s prescribing information should be consulted for complete details.

Reviews

Clinical studies demonstrate that Phoslo effectively reduces serum phosphorus levels in dialysis patients, with many achieving target phosphorus levels of 3.5-5.5 mg/dL. Nephrologists report satisfactory phosphate control in approximately 70-80% of patients when combined with dietary management. Some patients note gastrointestinal discomfort initially, which often resolves with continued use. Long-term users appreciate the predictable binding capacity and the additional calcium supplementation. Healthcare providers value the established safety profile and the ability to titrate dosage based on meal content and laboratory values.