TETANUS ANTITOXIN 1500IU INJECTION

Indications

• Prevention of tetanus in infants, children, and adults
• Post-exposure prophylaxis following potential exposure to tetanus
• Booster doses for adults every 10 years, or after specific injuries

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines, which typically include a series of vaccinations starting in infancy.

Adults: Refer to the BNF for specific dosing guidelines, as it may vary based on previous vaccination history and risk of exposure.

Mechanism of action

Antitetanus works by inducing the formation of neutralizing antibodies against the tetanospasmin toxin produced by Clostridium tetani. Upon administration, the inactivated toxin (toxoid) is recognized by the immune system, which then activates B lymphocytes to produce specific antibodies. These antibodies bind to the toxin and prevent its action, thereby offering protection against the effects of tetanus.

Pharmacodynamics

The pharmacodynamics of antitetanus involves the immune response generated following vaccination. The vaccine elicits a humoral immune response, leading to an increase in plasma cells that produce immunoglobulin G (IgG) antibodies against the tetanus toxin. This immune response typically takes several weeks to develop, providing long-term immunity that can be boosted with additional doses as needed.

Pharmacokinetics

Antitetanus vaccines are administered intramuscularly, allowing for rapid absorption. The peak antibody response occurs within 2 to 4 weeks after vaccination. Antibodies may persist for several years, but booster doses are recommended to maintain immunity, particularly for individuals at higher risk of exposure to tetanus.

Adverse effects

• Local pain or swelling at the injection site
• Fever
• Allergic reactions
• Anaphylaxis (rare)
• Systemic reactions (rare)

Precautions

• Use with caution in individuals with a history of allergic reactions to any vaccine or immunoglobulin
• Patients with immunocompromised status may have a reduced response
• Consider the risk of hypersensitivity reactions

Pregnancy

Antitetanus vaccination is generally considered safe during pregnancy and is recommended to protect the mother and fetus from tetanus.

Breast-feeding

Antitetanus vaccination is safe during breastfeeding. Antibodies can be transferred to the infant through breast milk.

Storage

Store in a refrigerator at 2-8°C. Do not freeze.

Formulations

• Tetanus toxoid
• Tetanus immunoglobulin

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)