RHOCLONE

Indications

• Primary immunodeficiency disorders
• Secondary immunodeficiency states
• Autoimmune diseases such as Guillain-Barré syndrome
• Certain infections including viral hepatitis
• Prevention of infections in immunocompromised patients

Dosage

Children: Refer to the BNF for Children for appropriate dosing information tailored to paediatric patients.

Adults: Refer to the BNF for specific dosing information as it varies based on the condition being treated.

Mechanism of action

Immunoglobulins work by binding to specific antigens on pathogens, marking them for destruction by other immune cells. This can involve neutralization of toxins, opsonization for phagocytosis, and activation of the complement system, leading to enhanced clearance of pathogens and modulation of immune responses.

Pharmacodynamics

The pharmacodynamics of immunoglobulins are characterized by their ability to modulate immune responses. They can enhance the activity of phagocytic cells, inhibit the proliferation of certain cells in the immune system, and alter the production of cytokines. The specific effects depend on the subclass of immunoglobulin and the nature of the disease being treated.

Pharmacokinetics

Immunoglobulins are typically administered intravenously or subcutaneously. They have a half-life that can vary widely depending on the specific product, ranging from several days to weeks. After administration, they distribute throughout the body, with a significant portion remaining in the vascular compartment. Metabolism occurs primarily through proteolytic degradation and clearance by the reticuloendothelial system.

Interactions

• antifungals, azoles + acalabrutinib: Severe (increases exposure)
• dronedarone + antipsychotics, second generation: Severe (increases exposure)
• mexiletine + antiarrhythmics: Severe (increases risk of torsade de pointes)
• mitotane + antiarrhythmics: Severe (decreases exposure)
• carbamazepine + antipsychotics, second generation: Severe (increases risk of myelosuppression)
• antiepileptics (carbamazepine, fosphenytoin, phenobarbital, phenytoin, primidone) + elexacaftor: Severe (decreases exposure)
• antiepileptics (carbamazepine, fosphenytoin, oxcarbazepine, phenobarbital, phenytoin, primidone) + imatinib: Severe (decreases exposure)
• iron chelators + antiepileptics: Severe (decreases absorption)
• lumacaftor + antiepileptics: Severe (decreases exposure)
• antiepileptics (fosphenytoin, phenobarbital, phenytoin, primidone) + metyrapone: Severe (decreases effects)

Indications

• Primary immunodeficiency disorders
• Secondary immunodeficiency (e.g. due to HIV infection)
• Chronic inflammatory demyelinating polyneuropathy (CIDP)
• Immune thrombocytopenic purpura (ITP)
• Kawasaki disease
• Prevention of infections in at-risk populations (e.g. following bone marrow transplant)

Dosage

Children: Refer to the BNF for Children for age-appropriate dosing guidelines; specific doses depend on the clinical condition and patient age.

Adults: Refer to specific guidelines for dosing based on indication; typically varies based on clinical scenario and patient condition.

Mechanism of action

Immunoglobulin exerts its effects primarily through the neutralization of pathogens and toxins, opsonization, and the activation of the complement system. It modulates immune responses by influencing the activity of various immune cells, including B cells, T cells, and macrophages, thereby enhancing antibody production and regulating inflammation.

Pharmacodynamics

The pharmacodynamics of immunoglobulin involve its ability to bind to specific antigens, effectively neutralizing them and facilitating their clearance. It also plays a crucial role in modulating the immune response, providing immediate passive immunity and promoting the establishment of active immunity over time. The diverse mechanisms through which immunoglobulin operates include antibody-dependent cell-mediated cytotoxicity (ADCC) and inhibition of pro-inflammatory cytokines.

Pharmacokinetics

Immunoglobulin is typically administered intravenously or subcutaneously. After administration, it is distributed throughout the extracellular space. The half-life of immunoglobulin varies but is generally in the range of 21 to 30 days, depending on the specific formulation and the patient's individual characteristics. It is primarily eliminated through the reticuloendothelial system, with catabolism occurring in various tissues.

Contra-indications

• Hypersensitivity to immunoglobulin preparations
• Selective IgA deficiency with a history of hypersensitivity
• Severe hyperprolinemia

Adverse effects

• Headache
• Nausea
• Fever
• Chills
• Fatigue
• Rash
• Anaphylactic reactions
• Thromboembolic events

Interactions

• Live attenuated vaccines may be less effective if administered concurrently with immunoglobulin therapy
• Caution is advised when administering with other blood products

Precautions

• Monitor for signs of anaphylaxis during and after administration
• Use with caution in patients with renal impairment
• Hydrate adequately to prevent renal dysfunction
• Consider the risk of thrombosis in patients with a history of thromboembolic events

Pregnancy

Immunoglobulin can be used during pregnancy if indicated, as it is considered safe based on available data.

Breast-feeding

Immunoglobulin is excreted in breast milk, but is generally considered safe during breastfeeding.

Storage

Store at 2-8 degrees Celsius. Do not freeze. Protect from light. Use before expiry date.

Formulations

• Intravenous immunoglobulin (IVIG)
• Subcutaneous immunoglobulin (SCIG)
• Intramuscular immunoglobulin (IMIG)