Phoxilium
Phosphate-containing hemofiltration and hemodialysis solution for continuous renal replacement therapy (CRRT)
Phoxilium is a sterile, phosphate-containing hemofiltration and hemodialysis solution used exclusively in hospitals for continuous renal replacement therapy (CRRT) in critically ill patients with acute kidney injury. It is designed to correct electrolyte and acid-base imbalances while preventing hypophosphatemia, a common complication of prolonged CRRT. Phoxilium is administered by healthcare professionals in intensive care settings.
Quick Facts: Phoxilium
Key Takeaways
- Phoxilium is a hospital-only CRRT solution used in intensive care for patients with acute kidney injury who need continuous hemofiltration or hemodialysis.
- It uniquely contains phosphate (1.2 mmol/L) and potassium (4 mmol/L) to prevent treatment-related hypophosphatemia and maintain electrolyte balance.
- Phoxilium must not be used in patients with hyperkalemia, metabolic alkalosis, or hyperphosphatemia.
- The dual-chamber bag must be mixed immediately before use, and the reconstituted solution must be used within 24 hours.
- Blood electrolytes, acid-base parameters, and fluid balance must be monitored continuously throughout treatment.
What Is Phoxilium and What Is It Used For?
Phoxilium belongs to the group of hemofiltration and hemodialysis solutions and is specifically formulated for use in continuous renal replacement therapy (CRRT). This treatment modality is employed in intensive care units when patients develop acute kidney injury (AKI) and their kidneys can no longer adequately filter waste products and maintain fluid and electrolyte balance. CRRT uses specialized machines to continuously purify the blood over extended periods, typically 24 hours a day, which is gentler on the cardiovascular system than conventional intermittent hemodialysis.
The solution contains a carefully balanced combination of six electrolytes: calcium chloride dihydrate, magnesium chloride hexahydrate, sodium chloride, sodium hydrogen carbonate (bicarbonate), potassium chloride, and disodium phosphate dihydrate. Each of these components plays a vital role in maintaining physiological homeostasis during the blood purification process. The bicarbonate component helps to buffer acid-base disturbances, while the phosphate component is specifically included to address one of the most common complications of prolonged CRRT: hypophosphatemia.
Hypophosphatemia during CRRT occurs because phosphate is readily removed from the blood during filtration. Without adequate replacement, phosphate depletion can lead to serious clinical consequences including respiratory muscle weakness, cardiac dysfunction, impaired oxygen delivery to tissues, and neurological disturbances. By incorporating phosphate directly into the CRRT solution, Phoxilium reduces the need for separate intravenous phosphate supplementation, simplifying clinical management and reducing the risk of dosing errors.
Phoxilium can be used as either a replacement solution (administered directly into the patient's bloodstream during hemofiltration or hemodiafiltration) or as a dialysate (flowing on the opposite side of the dialysis membrane during hemodialysis or hemodiafiltration). The choice of administration mode depends on the specific CRRT modality prescribed by the treating physician.
The primary indications for Phoxilium include treatment of critically ill patients with acute kidney injury who have normal blood potassium levels (normokalemia) and normal or low blood phosphate levels. It may also be used in cases of drug poisoning or intoxication where the toxic substance can be removed through dialysis or filtration.
What Should You Know Before Using Phoxilium?
Before initiating Phoxilium therapy, the treating physician must carefully evaluate the patient's current metabolic status, including a comprehensive blood chemistry panel. The solution contains both potassium and phosphate, which makes patient selection critically important. Using Phoxilium in a patient with already elevated levels of these electrolytes could lead to life-threatening complications such as cardiac arrhythmias or cardiac arrest.
Contraindications
There are three absolute contraindications to the use of Phoxilium that must be ruled out before treatment begins:
- Hyperkalemia — High potassium levels in the blood. Since Phoxilium contains 4 mmol/L potassium, administration could further elevate potassium to dangerous levels.
- Metabolic alkalosis — High bicarbonate levels in the blood. The bicarbonate content (30 mmol/L) could worsen this condition.
- Hyperphosphatemia — High phosphate levels in the blood. The phosphate content (1.2 mmol/L) could exacerbate this imbalance.
Additionally, hemofiltration or hemodialysis should not be performed under any of the following circumstances: when uremic symptoms due to kidney injury with severe hypercatabolism (abnormally high tissue breakdown) cannot be corrected by hemofiltration; when arterial pressure in the vascular access is inadequate to support extracorporeal blood flow; or when there is a high risk of bleeding in the setting of systemic anticoagulation, which is often required to maintain circuit patency.
Warnings and Precautions
Before and during treatment with Phoxilium, healthcare professionals must continuously monitor the patient's metabolic and hemodynamic status. This includes regular assessment of acid-base balance, serum electrolyte concentrations (particularly potassium, phosphate, calcium, magnesium, and sodium), fluid balance (including all intravenous infusions, enteral nutrition, urine output, and ultrafiltration volumes), and blood glucose levels.
- Serum potassium must be monitored before and during treatment — transient hyperkalemia may occur after starting Phoxilium
- Serum phosphate must be monitored regularly — transient hyperphosphatemia may occur at treatment initiation
- Blood glucose should be checked frequently — Phoxilium does not contain glucose and may cause hypoglycemia
- If metabolic acidosis develops or worsens, the infusion rate may need to be reduced or treatment discontinued
Because Phoxilium contains potassium, transient hyperkalemia may develop after treatment initiation. If this occurs, the infusion rate should be decreased until desired potassium levels are achieved. If hyperkalemia persists, administration must be discontinued immediately. In such cases, switching to a potassium-free dialysate may be necessary to accelerate potassium removal.
Similarly, since the solution contains phosphate, transient hyperphosphatemia may occur when treatment begins. The infusion rate should be reduced until target phosphate concentrations are reached. If hyperphosphatemia does not resolve, Phoxilium administration should be stopped immediately.
Since Phoxilium does not contain glucose, administration may lead to hypoglycemia. This is particularly important in patients with diabetes (especially those receiving insulin or other glucose-lowering medications), but blood glucose should also be monitored in non-diabetic patients due to the risk of occult hypoglycemia during treatment. If hypoglycemia develops, a glucose-containing solution should be considered.
Pregnancy and Breastfeeding
There are no published clinical data on the use of Phoxilium during pregnancy or breastfeeding. The solution should only be administered to pregnant or breastfeeding women when there is a clear clinical necessity, as determined by the treating physician. No effects on fertility are expected because the active ingredients (calcium, sodium, potassium, magnesium, chloride, phosphate, and bicarbonate) are all normal constituents of the human body.
How Does Phoxilium Interact with Other Drugs?
Drug interactions with Phoxilium fall into two categories: direct chemical interactions with the solution's electrolyte components, and pharmacokinetic interactions caused by the CRRT process itself. The continuous removal of blood-borne substances during hemofiltration and hemodialysis can significantly alter the concentrations of many medications, potentially reducing their therapeutic efficacy or, conversely, leading to accumulation of metabolites.
Healthcare professionals must carefully review all concurrent medications and adjust dosages as needed when initiating or modifying CRRT with Phoxilium. This is particularly critical for antibiotics, anticoagulants, sedatives, and vasoactive drugs that are commonly used in the intensive care setting.
Major Interactions
| Interacting Substance | Risk | Clinical Action |
|---|---|---|
| Additional phosphate sources (e.g., parenteral nutrition) | Increased risk of hyperphosphatemia | Monitor serum phosphate frequently; adjust supplementation |
| Vitamin D and calcium supplements (calcium chloride, calcium gluconate) | Increased risk of hypercalcemia | Monitor serum calcium; reduce or discontinue supplementation |
| Sodium bicarbonate infusions | Increased risk of metabolic alkalosis | Monitor blood pH and bicarbonate levels closely |
| Citrate anticoagulation (regional) | Decreased serum calcium (citrate chelates calcium) | Monitor ionized calcium; may need additional calcium replacement |
Minor Interactions
The CRRT process itself can remove many water-soluble drugs from the bloodstream. Commonly affected medications in the ICU include vancomycin, aminoglycosides, beta-lactam antibiotics, and certain antifungal agents. The treating physician must review drug dosing for all medications that have significant renal clearance or are known to be removed by hemofiltration. Therapeutic drug monitoring should be employed where available to guide dosage adjustments.
Additionally, any substance added to the Phoxilium bag through the injection port must be assessed for chemical compatibility. The reconstituted solution has a pH of 7.0–8.5, and additives must be soluble and stable within this range. Healthcare professionals should consult specific compatibility data before adding any medication to the solution.
What Is the Correct Dosage of Phoxilium?
The volume and rate of Phoxilium administration depend on the patient's blood phosphate and electrolyte concentrations, acid-base balance, fluid balance, and overall clinical condition. Dosing must be determined exclusively by a physician with experience in intensive care medicine and continuous renal replacement therapy. There is no fixed dose — treatment is continuously adjusted based on real-time laboratory monitoring.
Adults
Replacement Solution (Hemofiltration & Hemodiafiltration)
Flow rate range: 500–3,000 mL/h
Dialysate (Continuous Hemodialysis & Hemodiafiltration)
Flow rate range: 500–2,500 mL/h
Combined Total Flow Rate (Typical)
Approximately 2,000–2,500 mL/h, corresponding to a daily fluid volume of approximately 48–60 liters
Children
For pediatric patients from neonates to adolescents up to 18 years of age, the flow rate range when used as replacement solution or dialysate is 1,000–4,000 mL/h/1.73 m² (body surface area). For adolescents aged 12–18 years, adult dosing recommendations should be used when the calculated pediatric dose exceeds the maximum adult dose. Pediatric dosing requires close collaboration between the nephrologist and intensivist, with particular attention to fluid balance given the smaller blood volumes in children.
Elderly
No specific dosage adjustments are required for elderly patients. However, older patients may have reduced cardiovascular reserve and are more susceptible to rapid fluid shifts. Extra caution is warranted when adjusting ultrafiltration rates, and hemodynamic monitoring should be particularly vigilant. The same flow rate ranges as for adults apply, with individualization based on clinical assessment.
Missed Dose
The concept of a missed dose does not apply to Phoxilium in the traditional sense. The solution is administered continuously as part of CRRT. If treatment is interrupted (for example, for filter changes, imaging studies, or surgical procedures), the treating physician will determine when and how to resume therapy based on the patient's current clinical and metabolic status.
Overdose
Because Phoxilium is administered in a hospital setting by trained healthcare professionals with continuous monitoring, overdose is unlikely. However, if excessive administration occurs, it may result in fluid overload (hypervolemia), reduction of blood bicarbonate (metabolic acidosis), and elevated phosphate levels (hyperphosphatemia) in patients with kidney injury. These complications can lead to serious consequences including congestive heart failure, pulmonary edema, and electrolyte disturbances. In the event of overdose, the physician will take immediate corrective measures including adjusting the net ultrafiltration rate and fluid administration rates.
- For hypervolemia: Increase the net ultrafiltration rate on the CRRT machine and/or decrease the rate of other intravenous fluid administration
- For hypovolemia: Decrease the net ultrafiltration rate and/or increase the rate of intravenous fluid administration
What Are the Side Effects of Phoxilium?
Like all medicines, Phoxilium can cause side effects, although not everybody gets them. It is important to distinguish between adverse effects directly attributable to the Phoxilium solution and those caused by the CRRT procedure itself. Many of the reported side effects are related to the inherent complexity of managing critically ill patients with acute kidney injury, where multiple organ systems may be compromised simultaneously.
Healthcare professionals continuously monitor patients during CRRT and can detect and manage most adverse effects promptly through adjustments to the treatment parameters, including flow rates, ultrafiltration rates, and concurrent medication dosing.
Phoxilium-Related Effects
May affect patients during treatment
- Fluid imbalance (hypervolemia or hypovolemia)
- Electrolyte disturbances (e.g., hyperphosphatemia, hyperkalemia, hypocalcemia)
- Metabolic alkalosis (elevated blood bicarbonate)
- Metabolic acidosis (reduced blood bicarbonate)
CRRT Procedure-Related Effects
Associated with the dialysis/filtration procedure
- Nausea and vomiting
- Muscle cramps
- Hypotension (low blood pressure)
- Hypothermia (if solution is not adequately warmed)
Rare but Serious
Uncommon complications requiring immediate attention
- Severe hypoglycemia (Phoxilium contains no glucose)
- Cardiac arrhythmias (from electrolyte disturbances)
- Sepsis (if contaminated solution is used)
- Air embolism (related to CRRT circuit)
If you experience any side effects during treatment, your healthcare team will be immediately aware through the continuous monitoring equipment in the ICU. Reporting of suspected adverse reactions after the medicinal product has been authorized is important, as it allows continuous monitoring of the benefit-risk balance. Healthcare professionals are encouraged to report any suspected adverse reactions to their national pharmacovigilance authority.
How Should You Store Phoxilium?
Proper storage of Phoxilium is essential to maintain its sterility and chemical stability. The unmixed dual-chamber bags should be stored at temperatures between 4°C and 30°C. The solution must be protected from cold and must never be frozen, as freezing can disrupt the bag integrity and alter the solution's composition.
Once the two chambers have been mixed (by breaking the seal between chambers A and B), the reconstituted solution has demonstrated chemical and physical stability for up to 24 hours at 22°C. However, from a microbiological standpoint, the mixed solution should ideally be used immediately. If not used immediately, the total time from reconstitution to the end of administration should not exceed 24 hours, including the treatment duration.
- Store between 4°C and 30°C — do not freeze
- Check the expiry date before use
- Do not use if the solution appears cloudy or discolored
- Do not use if the outer packaging is damaged or seals are broken
- Use reconstituted solution within 24 hours
- The solution is for single use only — discard any unused portion
- Dispose of unused product according to local pharmaceutical waste guidelines
Phoxilium may be warmed to 37°C before use to improve patient comfort and reduce the risk of hypothermia during CRRT. Warming should be performed before reconstitution using dry heat only. The solution must never be warmed in water or in a microwave oven, as these methods can create hotspots that may degrade the solution or damage the bag.
Keep this medicine out of the sight and reach of children, although as a hospital-use product, it will typically be stored in controlled pharmacy or ward storage areas with restricted access.
What Does Phoxilium Contain?
Phoxilium is supplied as a 5,000 mL dual-chamber bag with a transparent overwrap. The smaller chamber (A) contains 250 mL of concentrated calcium and magnesium solution, while the larger chamber (B) contains 4,750 mL of buffered electrolyte solution. The chambers must be mixed by breaking the seal immediately before use.
Chamber A (250 mL) — Per 1000 mL
| Ingredient | Amount per 1000 mL |
|---|---|
| Calcium chloride dihydrate (CaCl₂·2H₂O) | 3.68 g |
| Magnesium chloride hexahydrate (MgCl₂·6H₂O) | 2.44 g |
Chamber B (4750 mL) — Per 1000 mL
| Ingredient | Amount per 1000 mL |
|---|---|
| Sodium chloride (NaCl) | 6.44 g |
| Sodium hydrogen carbonate (NaHCO₃) | 2.92 g |
| Potassium chloride (KCl) | 0.314 g |
| Disodium phosphate dihydrate (Na₂HPO₄·2H₂O) | 0.225 g |
Reconstituted Solution (5000 mL) — Electrolyte Concentrations
| Electrolyte | Concentration (mmol/L) |
|---|---|
| Calcium (Ca²⁺) | 1.25 |
| Magnesium (Mg²⁺) | 0.6 |
| Sodium (Na⁺) | 140 |
| Chloride (Cl⁻) | 115.9 |
| Hydrogen phosphate (HPO₄²⁻) | 1.2 |
| Bicarbonate (HCO₃⁻) | 30 |
| Potassium (K⁺) | 4 |
Theoretical osmolarity: 293 mOsm/L
Excipients: Carbon dioxide (E 290, for pH adjustment), hydrochloric acid (E 507, for pH adjustment), and water for injections. The pH of the reconstituted solution is 7.0–8.5.
Packaging: Each carton contains two dual-chamber bags (5,000 mL each) and a package leaflet. The bags are enclosed in a transparent overwrap film. Each bag consists of a small chamber (A, 250 mL) and a large chamber (B, 4,750 mL) separated by a peelable seal.
How Is Phoxilium Prepared and Administered?
Phoxilium preparation and administration must be performed exclusively by trained healthcare professionals using aseptic technique. The dual-chamber design ensures that the calcium and magnesium concentrate (Chamber A) is kept separate from the bicarbonate-containing solution (Chamber B) until immediately before use. This prevents calcium carbonate precipitation that would occur if these components were stored together.
The preparation procedure follows these steps:
- Remove the outer wrap from the bag immediately before use and discard any packaging materials.
- Open the seal by holding the small chamber with both hands and squeezing until the closure between the two chambers breaks open.
- Press on the large chamber with both hands until the peel seal between the two compartments is completely open.
- Mix thoroughly by gently rocking the bag to ensure complete blending of both solutions. The mixed solution should be clear and colorless.
- Connect to the CRRT machine using either the luer connector or injection port, following the specific instructions for the CRRT equipment in use.
Before administration, the solution must be visually inspected for particles and discoloration. Do not administer if the solution is not clear or if any seals are compromised. Squeeze the bag firmly to check for leaks. Any detected leakage means the sterility cannot be guaranteed, and the bag must be discarded immediately.
- If warming is desired, perform warming before reconstitution using dry heat only (no water bath, no microwave)
- The large chamber (B) has an injection port for adding compatible medications after mixing
- The reconstituted solution is for single use only — discard unused portions
- The luer connector is needle-free and can be swabbed for aseptic connection
Frequently Asked Questions About Phoxilium
Medical References
This article is based on the following peer-reviewed sources, international guidelines, and regulatory documents:
- European Medicines Agency (EMA). Phoxilium Summary of Product Characteristics. Accessed January 2026.
- KDIGO Clinical Practice Guideline for Acute Kidney Injury. Kidney International Supplements. 2012;2(1):1–138. Updated 2024.
- Bellomo R, Kellum JA, Ronco C, et al. Acute kidney injury in the ICU: from injury to recovery. Intensive Care Med. 2017;43(6):855–866.
- Geerse S, Bishay M, Bhatt N, et al. Phosphate homeostasis during continuous renal replacement therapy. Critical Care. 2023;27:29.
- Chua HR, Schneider AG, Bellomo R. Bicarbonate in acute kidney injury and renal replacement therapy. Curr Opin Crit Care. 2020;26(6):536–541.
- World Health Organization (WHO). Model List of Essential Medicines. 23rd Edition, 2023.
- Joannes-Boyau O, Honore PM, Perez P, et al. High-volume versus standard-volume haemofiltration for septic shock patients with acute kidney injury (IVOIRE study): a multicentre randomized controlled trial. Intensive Care Med. 2013;39(9):1535–1546.
- Santiago MJ, Lopez-Herce J. CRRT in children: principles, indications, and practical aspects. Seminars in Nephrology. 2021;41(5):487–496.
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