WINRHO SDF Solution for injection Ref.[50374] Active ingredients: Human normal immunoglobulin G

For intravenous or intramuscular use only.

2.1 Dose

Treatment of ITP

ADMINISTER WinRho SDF BY THE INTRAVENOUS ROUTE ONLY.

Proper care should be taken when calculating the dose of WinRho SDF to be administered. A confusion between International Units (IU) and micrograms (mcg) of product (1 mcg = 5 IU), could result in either an overdose that could lead to a severe hemolytic reaction or a dose too low to be effective.

Since Win Rho SDF is administered on a weight-based regimen per kilogram (kg), patient weight determination must be taken in kilograms (kg) as inappropriate use of pounds (lbs) will result in significant overdosing of WinRho SDF.

Please note that dose for WinRho SDF may be calculated using either international units (IU) or micrograms (mcg) per kilograms.

Table 1 provides dosing guidelines for ITP patients.

Table 1. ITP Dosing Guidelines (Intravenous use only):

• All patients should be monitored to determine clinical response by assessing platelet counts, RBCs, hemoglobin (Hgb), and reticulocyte levels [see Warnings and Precautions (5.2)]
  • Safety and efficacy of WinRho SDF in the treatment of ITP at doses exceeding 300 IU/kg (60 mcg/kg) has not been established. * Treatment is rarely indicated in patients with platelet count above 50x10 ⁹/L.
• To determine the dosage and number of vials needed for the treatment of ITP:

weight in lbs/2.21 = weight in kg

weight in kg X selected IU (mcg) dosing level = dosage

dosage / vial size = number of vials needed

Suppression of Rh Isoimmunization

Table 2. Rh Isoimmunization Dosing Guidelines:

• If the Rh status of the baby is not known at 72 hours, administer WinRho SDF to the mother at 72 hours after delivery. If more than 72 hours have elapsed, administer as soon as possible up to 28 days after delivery.
• If WinRho SDF is administered early in pregnancy for amniocentesis and chorionic villus sampling (before 34 weeks), then administer WinRho SDF repeatedly at 12-week interval to maintain adequate levels of passively acquired anti-Rh.

Incompatible Transfusion

Table 3. Incompatible Transfusion Dosing Guidelines:

For incompatible transfusion or massive fetal hemorrhage, treatment must occur within 72 hours and dose may be intravenous or intramuscular, based on the volume of blood or cells replaced.

2.2 Preparation

• Bring WinRho SDF to room temperature prior to use.
• Inspect WinRho SDF for particulate matter and discoloration prior to administration. Do not use if the solution is cloudy or contains particulates.
• WinRho SDF is for single use only. Discard any unused portion.
• The solution is ready to use, no reconstitution required.
• See Table 4 for the target fill volumes for each of the dosage sizes for WinRho SDF.

Table 4. Liquid WinRho SDF Dosage Size and Target Fill Volumes:

Note: Remove the entire contents of the vial to obtain the labelled dosage of WinRho SDF. If partial vials are required for dosage calculation, withdraw the entire contents of the vial to ensure accurate calculation of the dosage requirement. For ease in withdrawing the contents of the vial, draw back the plunger of a sterile syringe (with the needle and needle cover in place) to admit air into the syringe. Depress the plunger of the syringe to inject air into the vial. Invert vial and aspirate contents of vial into syringe.

2.3 Administration

Route of administration depends on the indication as follows:

ITP:

• Administer the entire dose of WinRho SDF into a suitable vein over three to five minutes.
• Administer WinRho SDF separately from other drugs.
• If dilution of WinRho SDF is preferred prior to intravenous administration, use only normal saline as diluent. Do not use Dextrose (5%) in water (D5W).

Suppression of Rh Isoimmunization:

• For intravenous administration, administer WinRho SDF separately from other drugs. WinRho SDF should be administered at a rate of 2 mL per 5 to 15 seconds.
• For intramuscular administration, administer into the deltoid muscle of the upper arm or the anterolateral aspects of the upper thigh. Due to the risk of sciatic nerve injury, avoid the gluteal region. If the gluteal region is used, use only the upper, outer quadrant.

Treatment of ITP and Suppression of Rh Isoimmunization

In post-marketing spontaneous reporting, there has been a limited number of medication error reports related to dosage calculations in which higher doses than that recommended for WinRho SDF were administered (doses >60 mcg/kg). Signs and laboratory findings of overdosage in Rh positive (ITP) patients have included hemoglobin decreases in excess of 1.2 g/dL. For the suppression of Rh isoimmunization, hemolytic reactions have been reported in cases of mis-matched blood transfusions where very large doses of WinRho SDF were administered.

In one ITP case report that involved an overdose due to confusion between mcg and international unit (IU), a patient with significant co-morbidities developed IVH and had a fatal outcome. In the event of overdose, monitor patients closely for signs and symptoms of hemolysis and initiate symptomatic and supportive treatment.

• Store at 2 to 8°C (36 to 46°F)
• Do not freeze
• Do not use after expiration date
• Protect from light