Defensor 3

Indications

• Influenza prevention
• Hepatitis A prevention
• Rabies prophylaxis
• Polio prevention
• Typhoid fever prevention

Dosage

Children: Refer to specific vaccine guidelines for paediatric dosing, as it varies depending on the vaccine type and indication.

Adults: Refer to specific vaccine guidelines for adult dosing, as it varies depending on the vaccine type and indication.

Mechanism of action

Killed vaccines work by presenting inactivated pathogens or their components (antigens) to the immune system. This exposure prompts the immune system to produce antibodies and memory cells, preparing the body to respond to future infections by the live version of the pathogen. The inactivation process ensures that the vaccine is safe and cannot cause disease.

Pharmacodynamics

The pharmacodynamics of killed vaccines involve the activation of the immune system, specifically the adaptive immune response. Upon administration, the immune system recognizes the inactivated antigens as foreign, leading to the activation of T-cells and B-cells. B-cells produce antibodies against the specific pathogen, which can remain in the body for a prolonged period, providing immunity against future infections. The response may vary based on the individual and the specific vaccine used.

Pharmacokinetics

Killed vaccines do not undergo metabolism in the traditional sense as they are not pharmacological agents that exert effects systemically. Instead, they are processed through the immune system. After administration, the inactivated pathogens are taken up by antigen-presenting cells, which process the antigens and present them to T-cells. The immune response can take days to weeks to develop fully. The duration of immunity may vary depending on the vaccine and the individual's immune response.

Pregnancy

Consult healthcare provider. Safety during pregnancy has not been established.

Breast-feeding

Consult healthcare provider. Safety during breastfeeding has not been established.

Storage

Store in a cool, dry place away from direct sunlight.

Indications

• Rabies prevention in individuals at high risk of exposure
• Post-exposure prophylaxis following potential rabies exposure
• Vaccination for travelers to endemic regions

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations for pediatric patients.

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

Mechanism of action

The rabies vaccine works by stimulating the immune system to produce antibodies against the rabies virus. This is achieved through the introduction of inactivated or attenuated virus particles, which mimic the infection without causing the disease. The immune response generated helps to prevent the virus from causing illness upon subsequent exposure.

Pharmacodynamics

The rabies vaccine induces an adaptive immune response, leading to the production of neutralizing antibodies specific to the rabies virus. This immune memory protects against future infections. The vaccine is typically administered in a series of doses to ensure adequate immune response and long-term protection.

Pharmacokinetics

The pharmacokinetics of the rabies vaccine involve absorption at the injection site, followed by systemic distribution of the antigens. The onset of immunity generally occurs within two weeks after the initial vaccination, with peak antibody levels typically reached within one to two months. The duration of immunity can vary, necessitating booster doses in certain populations.

Interactions

• chloroquine+rabiesvaccine: Severe (decreases efficacy)

Pregnancy

Rabies vaccination is generally considered safe during pregnancy. However, the risks and benefits should be carefully evaluated.

Breast-feeding

Rabies vaccine is not known to cause any adverse effects in breastfeeding. However, consult with a healthcare provider for individual assessments.

Storage

Store the rabies vaccine in a refrigerator at 2-8 degrees Celsius. Do not freeze.

Indications

• Prevention of infectious diseases such as measles, mumps, rubella, hepatitis B, influenza, and human papillomavirus (HPV)
• Travel vaccinations for diseases endemic to certain regions
• Vaccination for at-risk populations, such as those with compromised immune systems or specific occupational exposures

Dosage

Children: Dosage varies by vaccine type and age; refer to the BNF for Children for specific dosing information.

Adults: Dosage varies by vaccine type and indication; refer to specific guidelines for each vaccine.

Mechanism of action

Vaccines work by mimicking an infection. They introduce a harmless component of a pathogen (antigen) to the immune system, prompting the body to produce an immune response. This includes the generation of antibodies and memory cells that provide long-term immunity. Upon subsequent exposure to the actual pathogen, the immune system is primed to respond more rapidly and effectively.

Pharmacodynamics

The pharmacodynamics of vaccines involves the activation of both humoral and cellular immunity. Vaccines stimulate B cells to produce antibodies against the pathogen, while T cells are activated to destroy infected cells. This dual response helps to establish immunological memory, which enables a faster and more robust response upon re-exposure to the pathogen.

Pharmacokinetics

Vaccines are administered via various routes, including intramuscular, subcutaneous, and oral. After administration, the antigens are presented to antigen-presenting cells, which activate T cells and stimulate B cell proliferation and differentiation. The half-life of vaccine-induced immunity varies depending on the type of vaccine, with some providing lifelong immunity and others requiring booster doses to maintain protection.

Contra-indications

• Severe allergic reaction (anaphylaxis) to a component of the vaccine
• Severe immunocompromised state for live attenuated vaccines

Adverse effects

• Local reactions at the injection site (pain, redness, swelling)
• Fever
• Fatigue
• Headache
• Muscle pain
• Joint pain
• Nausea

Interactions

• Immunosuppressive medications may reduce vaccine efficacy
• Concurrent administration of some vaccines may require spacing to optimize immune response

Precautions

• History of allergic reactions to vaccines or vaccine components
• Pregnancy (specific vaccines may be contraindicated)
• Moderate to severe acute illness with or without fever

Pregnancy

Consult healthcare provider. Some vaccines are contraindicated during pregnancy, while others are recommended.

Breast-feeding

Generally considered safe, but consult healthcare provider regarding specific vaccines.

Storage

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

Formulations

• Liquid suspension for injection
• Lyophilized powder for reconstitution

Indications

• Influenza
• HIV/AIDS
• Hepatitis B and C
• Herpes simplex virus infections
• Cytomegalovirus infections
• COVID-19
• Respiratory syncytial virus infections

Dosage

Children: Refer to specific antiviral agents for dosing guidance.

Adults: Refer to specific antiviral agents for dosing guidance.

Mechanism of action

Viruses infect host cells by attaching to specific receptors on the cell surface. Once inside, they hijack the host cell's machinery to replicate their genetic material and produce viral proteins. New viral particles are assembled and released from the host cell, often destroying the cell in the process. The specific mechanism can vary depending on the virus type, including integration into the host genome in retroviruses or utilizing specific pathways for replication.

Pharmacodynamics

The pharmacodynamics of antiviral agents depend on the specific virus and the mechanism of action. Antiviral drugs may inhibit viral entry into host cells, block viral replication, or prevent the assembly of new virions. The effectiveness of antiviral therapy often relates to the stage of viral replication and the immune response of the host.

Pharmacokinetics

Pharmacokinetics of antiviral drugs varies widely based on the specific medication used. Generally, antiviral agents are absorbed through the gastrointestinal tract and distributed throughout the body. They may undergo hepatic metabolism and are often excreted through the kidneys. The half-life of these drugs can range from a few hours to several days, influencing dosing schedules.