About This Information

This section provides supplemental information related to the Kovaltry® Dose Calculator. It is intended to help healthcare professionals understand the calculator’s parameters, outputs, and the dosing principles it is based on. This material is for informational purposes only and does not replace the full Prescribing Information or clinical judgment.

Outputs Explained

The calculator provides the following key outputs based on the data entered:

• Calculated Dose (IU): The theoretical dose in International Units (IU) required to achieve the desired Factor VIII level, based on standard pharmacokinetic formulas.
• Recommended Vials: A suggested combination of Kovaltry® vial strengths (250, 500, 1000, 2000, 3000 IU) to meet or exceed the calculated dose.
• Total Dose Administered (IU): The actual total IU dose based on the sum of the recommended vials. This amount is typically rounded up from the calculated dose to the nearest 250 IU increment.
• Total Infusion Volume (mL): The final volume for administration, calculated by multiplying the total number of vials by the standard reconstitution volume of 2.5 mL per vial.

How to Use

To ensure accurate calculations, understand the required inputs:

• Calculation Mode: Select the clinical scenario: On-Demand Treatment for active bleeds, Routine Prophylaxis for preventative scheduling, or Perioperative Management for surgical procedures.
• Patient Weight: Enter the patient’s body weight. The calculator can accept values in kilograms (kg) or pounds (lbs), but all calculations are performed using kg.
• Desired Factor VIII Rise (%): For on-demand treatment, this is the target increase in Factor VIII activity level. The value is often guided by the severity of the bleed.
• Dose per Kilogram (IU/kg): For routine prophylaxis, this is the prescribed dose intensity for each infusion.

Dosing Overview

On-Demand Treatment and Control of Bleeding Episodes

The required dose is calculated using the formula: Dose (IU) = Body Weight (kg) × Desired Factor VIII Rise (%) × 0.5. The frequency of administration depends on the severity of the hemorrhage.

Routine Prophylaxis

The recommended starting regimen is 20 to 40 IU of Kovaltry® per kg of body weight two or three times per week. The regimen can be adjusted based on the patient’s clinical response.

Perioperative Management

Dosing is individualized based on the type of surgery (minor or major) and the patient’s status. Pre-operative doses aim to achieve a specific peak Factor VIII level (e.g., 80-100% for major surgery), with subsequent doses administered to maintain hemostasis during the recovery period.

Switching Patients to Kovaltry®

When switching a patient from another recombinant Factor VIII product, the starting prophylactic dose and regimen of Kovaltry® should be based on their previous regimen. Individual dose and interval adjustments may be necessary to achieve the desired clinical response. Close monitoring of the patient’s clinical status and Factor VIII levels is recommended during the transition period.

Missed Dose

If a patient misses a scheduled prophylactic dose, they should administer the dose as soon as they remember. They should then resume their regular dosing schedule. The patient should be instructed not to administer a double dose to make up for a missed dose. Consult the full prescribing information for detailed guidance.

Safety Alerts

This information is not a substitute for medical advice from a qualified healthcare professional. Always consult the full Prescribing Information before making any treatment decisions. Hypersensitivity reactions, including anaphylaxis, are possible with Kovaltry®. Development of neutralizing antibodies (inhibitors) to Factor VIII may occur.

Frequently Asked Questions

How does the calculator determine the required dose for on-demand treatment?

It uses the established pharmacokinetic formula: Dose (IU) = Body Weight (kg) × Desired Factor VIII Rise (%) × 0.5. This formula estimates the dose needed to achieve a specific plasma FVIII level.

Why is the “Total Dose Administered” often higher than the “Calculated Dose”?

The calculated dose is a precise theoretical value. The total administered dose is based on combining available vial strengths (250, 500, 1000, 2000, 3000 IU). The calculator rounds the required dose up to the nearest 250 IU increment to provide a practical combination of vials.

How is the total infusion volume determined?

Each vial of Kovaltry® is reconstituted with a standard volume of 2.5 mL of sterile water. The calculator determines the total number of vials needed and multiplies that number by 2.5 mL to find the total infusion volume.

Can I use this calculator for patients weighing in pounds (lbs)?

Yes. While the calculator accepts weight in pounds, it immediately converts the value to kilograms (kg) for the dosing formula, as the pharmacokinetic constant is based on kg.

What are the recommended Factor VIII rise percentages for different bleed severities?

General recommendations are: 20-40% for minor bleeds (e.g., early joint bleeds), 40-60% for moderate bleeds, and 80-100% for major or life-threatening bleeds.

What is the recommended dosing range for routine prophylaxis?

According to the prescribing information, the recommended range is 20 to 50 IU/kg, administered two or three times per week. The calculator defaults to common values but allows for customization within this range.

Does the calculator provide post-operative dosing recommendations?

The tool calculates the initial pre-operative dose and provides a general note about post-operative care based on whether the surgery is minor or major. However, all post-operative dosing must be individualized and based on continuous clinical assessment and laboratory monitoring.

Is this calculator suitable for pediatric patients?

The dosing principles apply to both adults and children. However, pediatric dosing may require more frequent monitoring and adjustment. Always refer to the full Prescribing Information for specific pediatric guidance.

References

1. Kovaltry® European Public Assessment Report (EPAR). European Medicines Agency.
2. Kovaltry® Official Healthcare Professional Website. Bayer.
3. Factor VIII (FVIII). National Hemophilia Foundation.