Rho(D) immune globulin (RhoGAM, Gamulin Rh, HypRho D, MicRhoGAM, Rhesonativ, HyperRHO, Rhophylac, WinRho SDF)

Dosing and uses of RhoGAM, Gamulin Rh (Rho(D) immune globulin)

• Adult
• Pediatric

 

Adult dosage forms and strengths

WinRho SDF, Rhophylac given IV/IM; others IM only

1500 International Unit ~300 mcg

 

Administer to Mother to Prevent Hemolytic Disease in Newborn

Antepartum: 1500 IU/300 mcg IV/IM at 28-30 weeks of gestation

Postpartum: 1500 IU IV/IM within 72 hr

If both given risk reduced to 0.1%

If unable to give within 72 hr, give within 28 d; do not withhold

If >15 mL of Rho+ fetal RBC present in mother's circulation, multiple 1500 IU doses are required

 

Obstetric Conditions (Abortion/Miscarriage)

1500 IU IV/IM x1 within 72 hr

HyperRHO/MicRhoGAM: If abortion within 13 weeks give 250 IU/50 mcg (minidose)

 

Immune Thrombocytopenic Purpura (Nonsplenectomized Rho(D)-Positive Patients)

Initial, Hgb >10 g/dL: 250 IU/kg IV x1

Initial, Hgb <10 g/dL: 125-200 IU/kg IV x1

Additional doses: 125-300 IU/kg IV PRn

Infuse IV over 3-5 min

If unresponsive to intital dose and Hgb <8 g/dL, use an alternate treatment

 

Incompatible Transfusions

WinRho SDF

• Exposure to Rh(D) positive whole blood
• IM: 12 mcg (60 IU)/mL blood
• IV: 9 mcg (45 IU)/mL blood

Rhophylac

• 20 mcg (100 IU)/2 mL blood (or 1 mL erythrocyte concentrate) IV/IM

 

Other Indications & Uses

To suppress immune response of Rho negative mothers exposed to Rho positive blood due to Rho positive neonate during childbirth, and thereby prevent hemolytic disease of newborn in future pregnancies

To suppress Rho immune response in Rho-negative women during obstetric complications or invasive procedures

Immune Thrombocytopenic Purpura in nonsplenectomized Rho(D)+ patients

Incompatible transfusions (Rho+ blood in Rho-negative individuals)

 

Pediatric dosage forms and strengths

Safety & efficacy not established; but given at doses proportionate with adult dose in childhood ITp

 

RhoGAM, Gamulin Rh (Rho(D) immune globulin) adverse (side) effects

Frequency not defined

Tenderness

Allergic reaction

Urticaria

Angioedema

Rare elevation in total bilirubin secondary to rapid RBC destruction when given following transfusion mismatch

 

Warnings

Black box warnings

Intravascular Hemolysis (IVH) with WinRho SDF

• Intravascular hemolysis (IVH) leading to death has been reported in patients treated for ITP with WinRho SDF
• IVH can lead to clinically compromising anemia and multisystem organ failure including acute respiratory distress syndrome (ARDS)
• Serious complications, including severe anemia, acute renal insufficiency, renal failure and disseminated intravascular coagulation (DIC) have also been reported
• Monitor closely in health care setting for at least 8 hr after administration
• Perform dipstick urinalysis at baseline, 2 hr, and 4 hr after administration and prior to end of the monitoring period
• Alert patients to signs and symptoms of IVH, including back pain, shaking chills, fever, and discolored urine or hematuria
• Absence signs and/or symptoms of IVH within 8 hr do not indicate IVH cannot occur subsequently
• Post-treatment laboratory tests should be performed if IVH suspected and include plasma hemoglobin, urinalysis, haptoglobin, LDH, and plasma bilirubin (direct and indirect)

 

Contraindications

Hemolytic Dz

• Rho(D)+
• Rho(D) negative women who are Rh immunized
• Hypersensitivity to immune globulins

Immune Thrombocytopenic Purpura

• Rho(D) negative individuals
• Splenectomized individuals
• Hypersensitivity to plasma products
• Autoimmune hemolytic anemia
• Pre-existing hemolysis or high risk for hemolysis
• Do not use WinRho SDF in patients with IgA deficency with antibioies against IgA

 

Cautions

NEVER GIVE TO NEONATe

Do not administer IM for ITp

WinRho SDF: risk of rare but potentially fatal intravascular hemolysis in ITP pts

Maltose-containing IVIG products (eg WinRho SDF) may give false highs in certain glucose-testing systems

Avoid live vaccines for 3 mth

IgA deficiency

Avoid gluteal IM if possible, if not inject only in upper outer quadrant

 

Pregnancy and lactation

Pregnancy category: C

Lactation: not known if excreted in breast milk, no adverse effects reported

 

Pregnancy categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

 

Pharmacology of RhoGAM, Gamulin Rh (Rho(D) immune globulin)

Half-Life: brand-dependent

 

Peak Plasma:

Im

• Time: 5-10 d
• Concentration: 18-19 ng/mL

IV

• Time: 2 hr
• Concentration: 36-48 ng/mL

 

Mechanism of action

Anti-Rho(D) immune globulins from human donors

 

Administration

IM

Administer to mother, not to infant

Administer into the deltoid muscle or upper outer side of the thigh

Do not use gluteal region as routine inj site (risk of injury to sciatic nerves), however if necessary, use only the upper, outer quadrant of gluteal muscle

The plunger of the syringe should be drawn back before injection to ensure that the needle is not in a blood vesseL

If blood or any unusual discoloration is present in the syringe, withdraw needle &discard syringe; administer new dose of Rho(D) IGIM at a different site using a new syringe & needle

Do not adminster RhoD IGIM by IV; however, RhoD IGIV may be administered Im

Do NOT administer IM for ITP Tx

WinRho SDF: dilute 600 IU & 1500 IU in 1.25 mL supplied diluent(s); for 5000 IU vial, use 8.5 mL

 

IV

For Rh suppression, administer to mother & not infant

Reconstitute vial contents with appropriate volume of NS by injecting supplied diluent (NS) slowly onto the inside wall of the vial & swirl vial gently until the lyophilized pellet has dissolved

Do not shake vial. Inspect for particulate matter and discoloration prior to administration

For 600 IU or 1500 IU vials, use 2.5 mL diluent; for 5000 IU vial, use 8.5 mL

Do not administer with other drugs

Administer direct inj Rhophylac at 2 mL/15-60 sec; WinRho SDF 1500 IU/5-15 sec