Gammagard Liquid Dosage

Recommended Dosage

For intravenous or subcutaneous use only.

Intravenous Administration

• Adjust frequency and dosage to achieve target serum IgG levels and clinical response.
• If a patient misses a dose, administer the missed dose as soon as possible, and then resume scheduled treatments every 3 or 4 weeks, as applicable.

Dose Adjustments for Measles Exposure

If a patient has been exposed to measles, it may be prudent to administer an extra dose of GAMMAGARD LIQUID ERC Intravenous as soon as possible and within 6 days of exposure. A dose of 400 mg/kg should provide a serum level >240 mIU/mL of measles antibodies for at least two weeks.

If a patient is at risk of future measles exposure and receives a dose of less than 530 mg/kg every 3 to 4 weeks, the dose should be increased to at least 530 mg/kg. This should provide a serum level of 240 mIU/mL of measles antibodies for at least 22 days after infusion.

Subcutaneous Administration

• Prior to switching from intravenous to subcutaneous treatment, obtain the patient's serum IgG trough level to guide subsequent dose adjustments.
• Start the initial subcutaneous dose approximately one week after the last intravenous infusion.

Dose Adjustments

Based on the results of clinical studies with GAMMAGARD LIQUID, the expected increase in serum IgG trough level during weekly subcutaneous treatment at the dose adjusted to provide a comparable AUC, is approximately 281 mg/dL higher than the last IgG trough level during prior stable intravenous treatment. To calculate the target trough IgG level for subcutaneous treatment, add 281 mg/dL to the IgG trough level obtained after the last intravenous treatment.

To guide dose adjustment, calculate the difference between the patient's target serum IgG trough level and the IgG trough level during subcutaneous treatment. Find this difference in the columns of Table 3 and the corresponding amount (in mL) by which to increase (or decrease) the weekly dose based on the patient's body weight. If the difference between measured and target trough levels is less than 100 mg/dL, then no adjustment is necessary. However, the patient's clinical response should be the primary consideration in dose adjustment.

Example 1: A patient with a body weight of 80 kg has a measured IgG trough level of 800 mg/dL and the target trough level is 1000 mg/dL. The desired target trough level difference is 200 mg/dL (1000 mg/dL minus 800 mg/dL). The weekly dose of GAMMAGARD LIQUID ERC should be increased by 30 mL (3.0 g).

Example 2: A patient with a body weight of 60 kg has a measured IgG trough of 1000 mg/dL and the target trough level is 800 mg/dL. The desired target trough level difference is 200 mg/dL (800 mg/dL minus 1000 mg/dL). The weekly dose of GAMMAGARD LIQUID ERC should be decreased by 23 mL (2.3 g).

Dose Adjustments for Measles Exposure

If a patient has been exposed to measles, administer a dose of GAMMAGARD LIQUID ERC Intravenous as soon as possible and within 6 days of exposure. A dose of 400 mg/kg Intravenous should provide a serum level >240 mIU/mL of measles antibodies for at least two weeks.

If a patient is at risk of future measles exposure and receives a dose of less than 242 mg/kg subcutaneously per week, the dose should be increased to 242 mg/kg subcutaneously weekly while at risk.

Preparation and Handling

• Inspect the drug product visually for particulate matter and discoloration prior to administration. GAMMAGARD LIQUID ERC is a clear or slightly opalescent, colorless, or pale-yellow solution. Do not use if the solution is cloudy, turbid, or if it contains particulates.
• GAMMAGARD LIQUID ERC is for single-dose only. Partially used vials should be discarded. GAMMAGARD LIQUID ERC contains no preservatives.
• Allow refrigerated products to come to room temperature before use. DO NOT MICROWAVE.
• Do not shake.
• Do not mix with other products.
• Do not use normal saline as a diluent. If dilution is desired, 5% dextrose in water (D5W) should be used as a diluent.
• The infusion line may be flushed with normal saline. An in-line filter is optional.
• Record the name and lot number of the product in the recipient's records.

Administration

Intravenous Administration

• For rate of intravenous infusion, refer to Table 2
• Monitor patient vital signs throughout the infusion. Certain adverse reactions (ARs) such as headaches, flushing, and changes in pulse rate and blood pressure may be related to the rate of infusion. Slow or stop infusion if adverse reactions occur. If symptoms subside promptly, the infusion may be resumed at a lower rate that does not result in recurrence of the symptoms.
• Adverse reactions may occur more frequently in patients receiving immune globulin for the first time, upon switching brands or if there has been a long interval since the previous infusion. In such cases, start at lower infusion rates and gradually increase as tolerated.
• Ensure that patients with pre-existing renal insufficiency are not volume depleted. For patients over 65 years of age or judged to be at risk for renal dysfunction or thrombotic events, administer GAMMAGARD LIQUID ERC at the minimum infusion rate practicable. In such cases, the maximal rate should be less than 3.3 mg/kg/min (<2 mL/kg/hr); consider discontinuation of administration if renal function deteriorates.

Subcutaneous Administration

Patients with a history of allergic reactions to immunoglobulin products should not be treated subcutaneously at home until 2 to 3 treatments have been administered and tolerated under medical supervision.

Selection of Infusion Site: Suggested areas for subcutaneous infusion of GAMMAGARD LIQUID ERC are abdomen, thighs, upper arms, or lower back. Infusion sites should be at least two inches apart, avoiding bony prominences. Rotate sites each week.

Volume per Site: The weekly dose (mL) should be divided by 30 or 20, based on patient weight above, to determine the number of sites required. Simultaneous subcutaneous infusion at multiple sites can be facilitated by using a multi-needle administration set.

Rate of Infusion

• For rate of intravenous infusion, refer to Table 2
• Patients 40 kg and Greater (88 lbs): If multiple sites are used, the rate set on the pump should be the rate per site multiplied by the number of sites (e.g., 30 mL x 4 sites = 120 mL/hr). The number of simultaneous sites should be limited to 8, or maximum infusion rate of 240 mL/hr.
• Patients Under 40 kg (88 lbs): If multiple sites are used, the rate set on the pump should be the rate per site multiplied by the number of sites (e.g., 20 mL x 3 sites = 60 mL/hr). The number of simultaneous sites should be limited to 8, or maximum infusion rate of 160 mL/hr.

Instructions for Subcutaneous Administration: Instruct patients and/or caregivers to observe the following procedures:

1. Aseptic technique - Use aseptic technique when preparing and infusing GAMMAGARD LIQUID ERC.

2. Assemble supplies - Set up a clean work area and gather all supplies necessary for the subcutaneous infusion: vial(s) of GAMMAGARD LIQUID ERC, ancillary supplies, sharps container and pump. If GAMMAGARD LIQUID ERC has already been pooled into a bag or a syringe, skip to Step 6.

3. Product preparation - Remove the protective cap from the vial to expose the center of the vial (Figure 1).

Figure 1

4. Wipe the stopper with an alcohol pad and allow it to dry (Figure 2).

Figure 2

5. Withdraw GAMMAGARD LIQUID ERC from the vials - Attach a sterile syringe to a needle and draw air into the syringe barrel equal to the amount of product to be withdrawn. Inject the air into the vial and withdraw the desired volume of GAMMAGARD LIQUID ERC (Figure 3). If multiple vials are required to achieve the desired dose, repeat this step.

Figure 3

6. Prepare the infusion pump and tubing - Follow the manufacturer's instructions for preparing the pump and administration tubing, if needed. Be sure to prime the pump tubing to ensure that no air is left in the tubing and needle.

7. Select the infusion sites - Select the number of infusion sites depending on the volume of the total dose. for recommended maximum volumes and rates. Potential sites for infusion include the back of arms, abdomen, thighs, and lower back (Figure 4, Figure 5). Ensure sites are at least 2 inches apart; avoid bony prominences.

Figure 4

Figure 5

8. Cleanse the infusion site(s) - Cleanse the infusion site(s) with an antiseptic skin preparation (e.g., alcohol pad) using a circular motion working from the center of the site and moving to the outside. Allow to dry (Figure 6).

Figure 6

9. Insert the needle - Choose the correct needle length to assure that GAMMAGARD LIQUID ERC is delivered into the subcutaneous space. Grasp the skin and pinch at least one inch of skin between two fingers. Insert needle at a 90-degree angle with a darting motion into the subcutaneous tissue. Secure the needle (Figure 7).

Figure 7

10. Check for proper needle placement - Prior to the start of infusion, check each needle for correct placement to make sure that a blood vessel has not been punctured. Gently pull back on the attached syringe plunger and monitor for any blood return in the needle set. If you see any blood, remove and discard the needle set. Repeat priming and needle insertion steps in a different infusion site with a new needle set (Figure 8).

Figure 8

11. Secure the needle to the skin - Secure the needle(s) in place by applying a sterile protective dressing over the site (Figure 9).

Figure 9

12. Start the infusion of GAMMAGARD LIQUID ERC - Follow the manufacturer's instructions to turn the pump on (Figure 9).

13. Document the infusion - Remove the peel-off label with product lot number and expiration date from the GAMMAGARD LIQUID ERC vial and place in treatment diary/logbook to keep track of the product lots used. Keep the treatment diary/logbook current by recording the time, date, dose, product label and any reactions after each infusion.

14. Remove needle set - After the infusion is complete, remove the needle set and gently press a small piece of gauze over the needle insertion site and cover with a protective dressing. Discard any unused solution and disposable supplies in accordance with local requirements.