AVAXIM 160 VACCINE (INACTIVATED HEPATITIS A) ONE DOSE (0.5ML) CONTAINS HEPATITIS A VIRUS, GBM STRAIN (INACTIVATED) 160 ELISA UNITS

Indications

• Acute viral hepatitis
• Chronic hepatitis B
• Chronic hepatitis C
• Autoimmune hepatitis
• Alcoholic hepatitis
• Non-alcoholic fatty liver disease

Dosage

Children: Paediatric dosing also varies significantly based on the specific condition and medication. As with adult dosing, it is important to refer to the BNF for Children for specific recommendations.

Adults: Dosing for adult patients varies widely depending on the specific antiviral agent used and the type of hepatitis. It is essential to refer to specific guidelines or the BNF for precise dosing.

Mechanism of action

In viral hepatitis, the viruses typically enter liver cells and replicate, leading to cellular injury and inflammation. The immune response to the infection contributes to liver damage. Antiviral therapies aim to inhibit viral replication, either by directly targeting viral enzymes or by modulating the host immune response.

Pharmacodynamics

The pharmacodynamics of antiviral agents used in hepatitis treatment involve the inhibition of viral replication, reduction of viral load, and improvement of liver function. This can lead to a decrease in serum liver enzymes (ALT and AST) and an improvement in clinical symptoms. In chronic hepatitis B and C, sustained virologic response is the goal, indicating effective viral suppression.

Pharmacokinetics

The pharmacokinetics of antiviral medications used for hepatitis can vary significantly depending on the specific drug. Generally, these agents are absorbed from the gastrointestinal tract, metabolized in the liver, and excreted through urine or feces. The half-lives of these drugs can vary, influencing dosing schedules.

Pregnancy

Consult medical guidelines as hepatitis can pose risks during pregnancy; specific management depends on the type of hepatitis.

Breast-feeding

Consult healthcare providers, as the safety of certain hepatitis medications during breastfeeding varies.

Storage

Store in a cool, dry place away from direct sunlight; specific storage conditions may vary based on the medication used.

Indications

• Hepatitis A
• Hepatitis B
• Influenza
• Polio
• Rabies
• Typhoid fever

Dosage

Children: Refer to specific product guidelines for paediatric dosing, as it varies by vaccine type and indication.

Adults: Refer to specific product guidelines for adult dosing, as it varies by vaccine type and indication.

Mechanism of action

Inactivated vaccines work by introducing a form of the pathogen that cannot cause disease into the body. This stimulates the immune system to produce antibodies and memory cells specific to the pathogen, allowing for a robust immune response upon future exposure. The immune system recognizes the inactivated pathogen as foreign, leading to the activation of T-cells and B-cells, which are crucial for long-term immunity.

Pharmacodynamics

The pharmacodynamics of inactivated vaccines involve the generation of an adaptive immune response. After vaccination, the body produces specific antibodies against the inactivated pathogen. The response typically includes both humoral immunity, characterized by antibody production, and cellular immunity, involving T-cell activation. The duration of immunity can vary, and booster doses may be required to maintain adequate protection.

Pharmacokinetics

Inactivated vaccines do not have a pharmacokinetic profile like traditional drugs since they do not enter systemic circulation in the same manner. Following administration, the vaccine components are taken up by antigen-presenting cells, which process and present the antigens to T-cells. The immune response is initiated locally at the site of injection and can be influenced by factors such as the route of administration and the presence of adjuvants that enhance the immune response.

Adverse effects

• Injection site reactions (pain, swelling, redness)
• Fever
• Fatigue
• Headache
• Myalgia
• Chills

Precautions

• Assess for allergies to vaccine components
• Monitor for allergic reactions post-administration
• Consider underlying health conditions that may affect immune response

Pregnancy

Inactivated vaccines are generally considered safe during pregnancy, but individual risk-benefit assessment is recommended.

Breast-feeding

Inactivated vaccines can be administered during breastfeeding without concern for adverse effects in the infant.

Storage

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

Formulations

• Inactivated viral vaccines
• Inactivated bacterial vaccines