Hizentra Dosage

Generic name: human immunoglobulin g
Dosage form: subcutaneous infusion

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For subcutaneous infusion only. Do not inject into a blood vessel.

Preparation and Handling

Hizentra is a clear and pale yellow to light brown solution. Do not use if the solution is cloudy or contains particulates.

  • Prior to administration, visually inspect each vial of Hizentra for particulate matter or discoloration, whenever the solution and container permit.
  • Do not freeze. Do not use any solution that has been frozen.
  • Check the product expiration date on the vial label. Do not use beyond the expiration date.
  • Do not mix Hizentra with other products.
  • Do not shake the Hizentra vial.
  • Use aseptic technique when preparing and administering Hizentra.
  • The Hizentra vial is for single-use only. Discard all used administration supplies and any unused product immediately after each infusion in accordance with local requirements.

Dosage

The dose should be individualized based on the patient's clinical response to Hizentra therapy and serum immunoglobulin G (IgG) trough levels.

Start treatment with Hizentra 1 week after the patient's last Immune Globulin Intravenous (Human) (IGIV) infusion. Before receiving treatment with Hizentra, patients need to have received IGIV treatment at regular intervals for at least 3 months. Before switching to Hizentra, obtain the patient's serum IgG trough level to guide subsequent dose adjustments (see below under Dose Adjustment).

Establish the initial weekly dose of Hizentra by converting the monthly IGIV dose into a weekly equivalent and increasing it using a dose adjustment factor. The goal is to achieve a systemic serum IgG exposure (area under the concentration-time curve [AUC]) not inferior to that of the previous IGIV treatment (see Pharmacokinetics [12.3]).

Initial Weekly Dose

To calculate the initial weekly dose of Hizentra, divide the previous IGIV dose in grams by the number of weeks between doses during the patient's IGIV treatment (e.g., 3 or 4); then multiply this by the dose adjustment factor of 1.53.

Initial Hizentra dose = Previous IGIV dose (in grams)
Number of weeks between IGIV doses
× 1.53

To convert the Hizentra dose (in grams) to milliliters (mL), multiply the calculated dose (in grams) by 5.

Dose Adjustment

Over time, the dose may need to be adjusted to achieve the desired clinical response and serum IgG trough level. To determine if a dose adjustment should be considered, measure the patient's serum IgG trough level 2 to 3 months after switching from IGIV to Hizentra. The target serum IgG trough level on weekly Hizentra treatment is projected to be approximately 290 mg/dL higher than the last trough level during prior IGIV therapy.

To adjust the dose based on trough levels, calculate the difference (in mg/dL) between the patient's serum IgG trough level and the target IgG trough level. Then find this difference in Table 1 (Column 1) and, based on the patient's body weight, the corresponding amount (in mL) by which to increase (or decrease) the weekly dose. The patient's clinical response should be the primary consideration in dose adjustment. Additional dosage increments may be indicated based on the patient's clinical response (infection frequency and severity).

Table 1: Adjustment (±mL) of the Weekly Hizentra Dose Based on the Difference (±mg/dL) From the Target Serum IgG Trough Level
Difference From Target IgG Trough Level (mg/dL) Body Weight (kg)
10 15 20 30 40 50 60 70 80 90 100 110 120
Dose Adjustment (mL per Week)*
*
Dose adjustment in mL is based on the slope of the serum IgG trough level response to Hizentra dose increments (5.3 mg/dL per increment of 1 mg/kg per week).
100 1 1 2 3 4 5 6 7 8 8 9 10 11
150 1 2 3 4 6 7 8 10 11 13 14 15 17
200 2 3 4 6 8 9 11 13 15 17 19 21 23
250 2 4 5 7 9 12 14 16 19 21 23 26 28
300 3 4 6 8 11 14 17 20 23 25 28 31 34
350 3 5 7 10 13 16 20 23 26 30 33 36 39
400 4 6 8 11 15 19 23 26 30 34 38 41 45
450 4 6 8 13 17 21 25 30 34 38 42 46 51
500 5 7 9 14 19 23 28 33 38 42 47 52 56

For example, if a patient with a body weight of 70 kg has an actual IgG trough level of 900 mg/dL and the target trough level is 1000 mg/dL, this results in a difference of 100 mg/dL. Therefore, increase the weekly dose of Hizentra by 7 mL.

Monitor the patient's clinical response, and repeat the dose adjustment as needed.

Dosage requirements for patients switching to Hizentra from another IGSC product have not been studied. If a patient on Hizentra does not maintain an adequate clinical response or a serum IgG trough level equivalent to that of the previous IGSC treatment, the physician may want to adjust the dose. For such patients, Table 1 also provides guidance for dose adjustment if their desired IGSC trough level is known.

Measles Exposure

If a patient is at risk of measles exposure (i.e., due to an outbreak in the US or travel to endemic areas outside of the US), the weekly Hizentra dose should be a minimum of 200 mg/kg body weight for two consecutive weeks. If a patient has been exposed to measles, ensure this minimum dose is administered as soon as possible after exposure.

Administration

Hizentra is for subcutaneous infusion only. Do not inject into a blood vessel.

Hizentra is intended for weekly subcutaneous administration using an infusion pump. Infuse Hizentra in the abdomen, thigh, upper arm, and/or lateral hip.

  • Injection sites – A Hizentra dose may be infused into multiple injection sites. Do not use more than 4 sites simultaneously. However, if more injection sites are needed for the full weekly dose, they can be used consecutively. Injection sites should be at least 2 inches apart. Change the actual site of injection with each weekly administration.
  • Volume – For the first infusion of Hizentra, do not exceed a volume of 15 mL per injection site. The volume may be increased to 20 mL per site after the fourth infusion and to a maximum of 25 mL per site as tolerated.
  • Rate – For the first infusion of Hizentra, the maximum recommended flow rate is 15 mL per hour per site. For subsequent infusions, the flow rate may be increased to a maximum of 25 mL per hour per site as tolerated. However, the maximum flow rate is not to exceed a total of 50 mL per hour for all sites combined at any time.

Follow the steps below and use aseptic technique to administer Hizentra.

1.
Assemble supplies – Gather the Hizentra vial(s), disposable supplies (not provided with Hizentra), and other items (infusion pump, sharps or other container, patient's treatment diary/log book) needed for the infusion.
2.
Wash hands – Thoroughly wash and dry hands. The use of gloves when preparing and administering Hizentra is optional.
3.
Clean surface – Thoroughly clean a flat surface using an alcohol wipe.
4.
Check vials – Carefully inspect each vial of Hizentra. Do not use the vial if the liquid looks cloudy, contains particles, or has changed color, if the protective cap is missing, or if the expiration date on the label has passed.
5.
Transfer Hizentra from vial(s) to syringe
  • Remove the protective cap from the vial to expose the central portion of the rubber stopper of the Hizentra vial.
  • Clean the stopper with an alcohol wipe and allow it to dry.
  • Attach a sterile transfer needle to a sterile syringe. Pull back on the plunger of the syringe to draw air into the syringe that is equal to the amount of Hizentra to be withdrawn.
  • Insert the transfer needle into the center of the vial stopper and, to avoid foaming, inject the air into headspace of the vial (not into the liquid).
  • Withdraw the desired volume of Hizentra.
 
When using multiple vials to achieve the desired dose, repeat this step.
Figure
6.
Prepare infusion pump and tubing – Follow the manufacturer's instructions for preparing the pump, using subcutaneous administration sets and tubing, as needed. Be sure to prime the tubing with Hizentra to ensure that no air is left in the tubing.
7.
Prepare injection site(s)
  • The number and location of injection sites depends on the volume of the total dose. Infuse Hizentra into a maximum of 4 sites simultaneously; each injection site should be at least 2 inches apart.
Figure
 
  • Using an antiseptic skin preparation, clean each site beginning at the center and working outward in a circular motion. Allow each site to dry before proceeding.
Figure
8.
Insert needle(s)
  • Grasp the skin between 2 fingers and insert the needle into the subcutaneous tissue.
  • If necessary, use sterile gauze and tape or transparent dressing to hold the needle in place.
Figure
 
  • Before starting the infusion, attach a sterile syringe to the end of the primed administration tubing and gently pull back on the plunger to make sure no blood is flowing back into the tubing. If blood is present, remove and discard the needle and tubing. Repeat the process beginning with step 6 (priming) using a new needle, new infusion tubing, and a different injection site.
Figure
9.
Start infusion – Follow the manufacturer's instructions to turn on the infusion pump.
10.
Record treatment – Remove the peel-off portion of the label from each vial used, and affix it to the patient's treatment diary/log book.
11.
Clean up – After administration is complete, turn off the infusion pump. Take off the tape or dressing and remove the needle set from the infusion site(s). Disconnect the tubing from the pump. Immediately discard any unused product and all used disposable supplies in accordance with local requirements. Clean and store the pump according to the manufacturer's instructions.

For self-administration, provide the patient with instructions and training for subcutaneous infusion in the home or other appropriate setting.

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