Rhophylac300 mcg/2 ml

Rhophylac is a purified human immunoglobulin preparation used for the following indications, classified by strength of evidence:

Established / Approved Indications

• Antenatal prophylaxis: Prevention of Rh(D) alloimmunization in Rh(D)-negative, non-sensitized pregnant women, typically given around 28 weeks of gestation.
• Postpartum prophylaxis: Given to an Rh(D)-negative mother within 72 hours after delivery of an Rh(D)-positive (or Rh-unknown) infant.
• After pregnancy loss or procedures: Following spontaneous or induced abortion, threatened abortion, ectopic pregnancy, hydatidiform mole, or invasive procedures such as amniocentesis, chorionic villus sampling, cordocentesis, or external cephalic version, in Rh(D)-negative women.
• Incompatible transfusion: After transfusion of Rh(D)-positive red blood cells or blood products to an Rh(D)-negative individual, to prevent alloimmunization (dose calculated by volume of Rh-positive cells received).
• Immune thrombocytopenic purpura (ITP): Treatment of chronic or acute ITP in Rh(D)-positive, non-splenectomized patients (with select intravenous formulations), to raise platelet count.

Not Indicated

Rhophylac is not used in Rh(D)-positive women for obstetric prophylaxis, and the ITP indication does not apply to Rh(D)-negative or splenectomized patients.

Human Anti-D Immunoglobulins contains purified human immunoglobulin G (IgG) with a standardized concentration of anti-Rho(D) (anti-Rh(D)) antibodies, prepared from pooled plasma of human donors who have been sensitized to the Rh(D) antigen. It is manufactured and screened according to standards for plasma-derived biological products.

Rhophylac is a plasma-derived, purified polyclonal immunoglobulin (IgG) product containing antibodies directed against the Rh(D) red blood cell antigen. It is used for passive immunoprophylaxis against Rh(D) alloimmunization in Rh(D)-negative individuals exposed to Rh(D)-positive red blood cells, and, in select intravenous formulations, for treatment of immune thrombocytopenic purpura. It is available as an intramuscular injection (prefilled syringe or vial) or, for certain brands, as an intravenous/intramuscular preparation.

Rhophylac belongs to the therapeutic class of immunoglobulins (specific immune globulins), specifically the anti-Rho(D) immune globulin subclass of plasma-derived biological products used for passive immunization.

Mechanism in Rh(D) Alloimmunization Prevention

Human Anti-D Immunoglobulins works by passive immunization. When fetal Rh(D)-positive red blood cells enter the circulation of an Rh(D)-negative mother, the exogenous anti-Rh(D) antibodies in Human Anti-D Immunoglobulins bind to these cells and mark them for clearance by the reticuloendothelial system (mainly the spleen) before the mother's own immune system can recognize the Rh(D) antigen and mount an active antibody response. This prevents maternal sensitization and protects future Rh(D)-positive pregnancies from hemolytic disease of the fetus and newborn.

Mechanism in Immune Thrombocytopenic Purpura

In Rh(D)-positive, non-splenectomized ITP patients, anti-Rh(D)-coated red blood cells occupy Fc receptors on splenic macrophages. This reduces macrophage-mediated destruction of antibody-coated platelets, resulting in a transient rise in platelet count.

Rhophylac is administered by intramuscular injection (and, for certain intravenous-labeled brands, by slow intravenous injection) by a trained healthcare professional in a clinical setting equipped to manage possible hypersensitivity reactions. It must not be given intravenously unless the specific product is licensed for intravenous use. Do not administer if the solution is discolored or contains particulate matter.

Live attenuated virus vaccines: Rhophylac may interfere with the immune response to live attenuated vaccines (e.g., measles, mumps, rubella, varicella). Such vaccines should generally be deferred for approximately 3 months after administration of Rhophylac, or Rhophylac should be delayed for at least 2 weeks after live vaccine administration, unless the clinical situation requires otherwise.

Other immunoglobulin products: Concurrent use with other immune globulin preparations should be avoided unless specifically directed, to prevent additive effects or interference with antibody screening tests.

Common side effects of Rhophylac include:

• Injection site pain, tenderness, or swelling
• Mild fever, chills, or malaise
• Headache and myalgia
• Fatigue

Less common but clinically important effects (more often seen with intravenous use in the ITP indication) include hemolysis (a decrease in hemoglobin, with hemoglobinuria), back pain, and rarely, severe hypersensitivity or anaphylactic reactions. Thromboembolic events have been reported rarely with immunoglobulin products; see Precautions and Warnings for further detail.

Rhophylac is specifically indicated for use during pregnancy for Rh(D) alloimmunization prophylaxis, and is used when clearly needed for this purpose. As with all medicines used in pregnancy, it should be given only under the guidance of a qualified physician, who will weigh the benefit of preventing Rh(D) sensitization against any potential risk. There is no established evidence of harm to the fetus when Rhophylac is used as directed for its approved obstetric indications. For breastfeeding mothers, small amounts of immunoglobulin may be present in breast milk; use during lactation should be discussed with a physician, though it is generally considered compatible with breastfeeding when clinically indicated. Always consult a physician before use in pregnancy or while breastfeeding.

• Hemolysis: Rhophylac can cause hemolysis, particularly relevant when used intravenously for the ITP indication. Hemoglobin should be monitored during and after treatment, and patients should be observed for signs of significant hemolysis (e.g., back pain, dark urine, decreased hemoglobin).
• Timing of administration: For obstetric indications, Rhophylac must be given within specific time windows (e.g., within 72 hours postpartum or after a sensitizing event) per standard protocols, as delayed administration may reduce effectiveness in preventing alloimmunization.
• Thromboembolic events: Thromboembolic events have been reported rarely with immunoglobulin products. Caution is advised in patients with cardiovascular risk factors, immobility, hyperviscosity, or a history of thrombosis.
• Route restriction: Some formulations of Rhophylac are for intramuscular use only and must not be given intravenously; confirm the correct route for the specific product before administration.
• Hypersensitivity: As with all plasma-derived products, patients should be observed for signs of hypersensitivity or anaphylaxis during and after administration.
• Rhophylac is derived from human plasma; although donors and plasma are screened, a theoretical risk of transmission of infectious agents cannot be completely excluded.

Specific data on overdosage of Rhophylac are limited. Administration of doses higher than recommended may theoretically increase the risk of hemolysis and other immune-mediated reactions. If an overdose is suspected or excessive dosing has occurred, seek immediate medical attention or contact emergency services; the patient should be monitored closely by a physician, including assessment of hemoglobin and signs of hypersensitivity.

Store in a refrigerator at 2°C to 8°C (36°F to 46°F). Do not freeze. Protect from light. Keep out of reach of children. Do not use if the vial or syringe has been frozen or if particulate matter or discoloration is observed.

Pediatric Use

Rhophylac is not used for Rh(D) alloimmunization prophylaxis in children, as this indication applies to pregnant individuals. For the ITP indication, use in pediatric patients is based on weight-adjusted dosing per specific product labeling; safety and efficacy in young children should be assessed individually by the treating physician, as data may be limited.

Elderly

Rhophylac is not typically indicated in elderly patients outside of the ITP indication. When used, caution regarding thromboembolic risk factors that are more common with advancing age is advised.

Renal/Hepatic Impairment

No well-established dose adjustment of Rhophylac is required for renal or hepatic impairment; however, caution and physician judgment are advised, particularly regarding fluid status and monitoring for adverse effects.

Rhophylac is typically given as a single dose at each indicated clinical event (e.g., once at approximately 28 weeks gestation, once postpartum, once after a sensitizing event). For ongoing pregnancies, repeat dosing may be required at defined intervals per antenatal care protocols. For the ITP indication, treatment may be a single dose or repeated based on platelet response and physician assessment; it is not intended as a continuous, indefinite therapy.

Certain lyophilized (freeze-dried) powder formulations of Rhophylac require reconstitution with the diluent supplied by the manufacturer immediately before use, following the specific product's instructions; the reconstituted solution should be used promptly and not stored for later use. Liquid (prefilled syringe or vial) formulations of Rhophylac do not require reconstitution and are ready for immediate use.

Human Anti-D Immunoglobulins is classified under: Immunoglobulins; Anti-Rho(D) immune globulins; Plasma-derived biological products; Passive immunizing agents.

Human Anti-D Immunoglobulins provides passive immunization by supplying preformed anti-Rh(D) antibodies. These antibodies bind Rh(D)-positive fetal or transfused red blood cells, promoting their clearance by the reticuloendothelial system and preventing the recipient's own immune system from forming antibodies against the Rh(D) antigen. In immune thrombocytopenic purpura, anti-Rh(D)-coated red blood cells saturate Fc receptors on splenic macrophages, reducing platelet destruction.

Rhophylac is not indicated for routine use in children for Rh(D) alloimmunization prophylaxis, since this indication is specific to pregnant individuals. In the treatment of immune thrombocytopenic purpura, Rhophylac may be used in Rh(D)-positive, non-splenectomized pediatric patients under specialist supervision, with dosing calculated on a per-kilogram body weight basis according to the specific product's labeling. Safety and efficacy for this use in very young children have not been as extensively established, and treatment should be individualized and monitored closely by a physician.