INFANRIX HEXA VACCINE

Indications

• Pregnancy prevention
• Menstrual cycle regulation
• Management of dysmenorrhea
• Treatment of endometriosis
• Acne management (off-label use)
• Reduction of menstrual-related symptoms

Dosage

Children: Paediatric dosing for combined hormonal contraceptives is generally not established; refer to the BNF for Children for guidance based on individual patient needs and clinical considerations.

Adults: The dosage of combined hormonal contraceptives varies by formulation; follow the specific BNF guidelines for the chosen product.

Mechanism of action

Combined hormonal contraceptives work by suppressing the hypothalamic-pituitary-ovarian axis. Estrogen and progestin work together to inhibit the release of gonadotropins (LH and FSH) from the pituitary gland, preventing follicular development and ovulation. Additionally, progestin alters the cervical mucus to inhibit sperm passage and modifies the endometrium to reduce the likelihood of implantation.

Pharmacodynamics

The pharmacodynamic effects of combined hormonal contraceptives include the prevention of ovulation, changes in cervical mucus, and alterations in the endometrial lining. These effects lead to a significant reduction in the likelihood of pregnancy when taken as directed. The effectiveness can be influenced by factors such as adherence to the regimen and interactions with other medications.

Pharmacokinetics

Combined hormonal contraceptives are typically absorbed rapidly after oral administration. The bioavailability can be affected by the first-pass metabolism in the liver. Estrogens are primarily metabolized in the liver, while progestins undergo hepatic metabolism as well. The elimination half-lives vary by specific formulation but generally range from several hours to a few days. These hormones are excreted primarily via urine and feces.

Interactions

• cobicistat + combined hormonal contraceptives: Severe (decreases efficacy)
• combined hormonal contraceptives + lenalidomide: Severe (increases risk of venous thromboembolism)
• lorlatinib + combined hormonal contraceptives: Severe (decreases exposure)
• pitolisant + combined hormonal contraceptives: Severe (decreases efficacy)
• combined hormonal contraceptives + pomalidomide: Severe (increases risk of venous thromboembolism)
• combined hormonal contraceptives + thalidomide: Severe (increases risk of venous thromboembolism)
• combined hormonal contraceptives + tizanidine: Severe (increases exposure)
• combined hormonal contraceptives (containing ethinylestradiol + voxilaprevir with sofosbuvir and velpatasvir): Severe (increases risk of increased ALT concentrations)
• combined hormonal contraceptives alter the exposure to lamotrigine and lamotrigine + combined hormonal contraceptives: Moderate (decreases efficacy)
• combined hormonal contraceptives + erlotinib: Moderate (increases exposure)

Pregnancy

Combined hormonal contraceptives are generally contraindicated in pregnancy due to the potential risks to the fetus and increased risk of thromboembolism in pregnant individuals.

Breast-feeding

The use of combined hormonal contraceptives during breastfeeding is not recommended in the first few weeks postpartum, as they may affect milk production.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Dosage

Children: Refer to the specific formulation or active ingredient for appropriate dosing guidelines.

Adults: Refer to the specific formulation or active ingredient for appropriate dosing guidelines.

Mechanism of action

The exact mechanism of action for enhanced formulations varies depending on the active ingredients involved. Generally, enhancements may involve increasing the absorption of a drug, modifying its pharmacokinetics, or enhancing its interaction with biological targets such as receptors or enzymes, thereby improving therapeutic outcomes. For example, certain formulations may utilize nanoparticles or liposomal delivery systems to enhance drug distribution and cellular uptake.

Pharmacodynamics

Enhanced formulations often exhibit improved pharmacodynamic profiles compared to their traditional counterparts. This can include increased potency, reduced side effects, or prolonged duration of action. The pharmacodynamic effects are highly dependent on the specific components of the formulation and their interactions with biological systems, such as receptor binding affinity and the modulation of signaling pathways.

Pharmacokinetics

The pharmacokinetics of enhanced formulations can significantly differ from standard formulations. Factors such as absorption rate, distribution volume, metabolism, and excretion may be optimized to achieve desired therapeutic levels more effectively. For instance, enhanced formulations may demonstrate improved bioavailability or modified half-lives due to the use of novel delivery systems that protect the active ingredient from degradation or facilitate its release over time.

Pregnancy

Consult healthcare professional. Limited data available on safety during pregnancy.

Breast-feeding

Consult healthcare professional. Safety during breastfeeding is not well established.

Storage

Store in a cool, dry place, away from light. Keep out of reach of children.

Indications

• Bacterial meningitis
• Pneumonia
• Epiglottitis
• Otitis media
• Sinusitis
• Bronchitis

Dosage

Children: Refer to specific antibiotic guidelines for pediatric dosing based on the type and severity of the infection caused by Haemophilus species.

Adults: Refer to specific antibiotic guidelines for dosing based on the type and severity of the infection caused by Haemophilus species.

Mechanism of action

H. influenzae adheres to epithelial cells via pili and other surface structures, allowing colonization of the nasopharynx. The encapsulated strains evade phagocytosis due to their polysaccharide capsule, which inhibits opsonization and complement activation. This leads to the systemic spread of the bacteria and can result in severe infections if not effectively treated.

Pharmacodynamics

H. influenzae can produce various virulence factors, including polysaccharide capsules, endotoxins, and enzymes that contribute to its pathogenicity. The bacteria can resist the effects of certain antibiotics through mechanisms such as beta-lactamase production, which hydrolyzes beta-lactam antibiotics, rendering them ineffective. The host's immune response is often inadequate to clear the infection due to the bacterium's ability to evade immune detection.

Pharmacokinetics

The pharmacokinetics of antibiotics used to treat H. influenzae infections vary based on the specific drug. Common antibiotics include ampicillin and ceftriaxone. The absorption, distribution, metabolism, and excretion depend on the antibiotic used. For example, ampicillin is well absorbed from the gastrointestinal tract, widely distributed in body tissues and fluids, and eliminated primarily via renal excretion.

Adverse effects

• Injection site reactions
• Fever
• Rash
• Irritability
• Anaphylaxis (rare)

Precautions

• Caution in patients with a history of severe allergic reactions
• Monitor for signs of anaphylaxis after administration
• Assess for underlying immunocompromised conditions

Pregnancy

Safety during pregnancy has not been established; use only if clearly needed.

Breast-feeding

Generally considered safe, but consult a healthcare provider.

Storage

Store at 2-8 degrees Celsius. Do not freeze. Protect from light.

Formulations

• Injectable suspension
• Oral tablets

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

Indications

• Influenza virus infection
• Prophylaxis of influenza in high-risk populations
• Treatment of suspected or confirmed influenza in children and adults

Dosage

Children: Refer to the specific antiviral medication's product information for dosing guidance.

Adults: Refer to the specific antiviral medication's product information for dosing guidance.

Mechanism of action

Antiviral medications targeting influenza, such as neuraminidase inhibitors (e.g., oseltamivir), work by inhibiting the neuraminidase enzyme on the surface of the virus. This inhibition prevents the release of new viral particles from infected cells, thus limiting the spread of the virus within the respiratory tract.

Pharmacodynamics

The pharmacodynamic effects of antiviral agents against influenza include a reduction in the severity and duration of symptoms, as well as a decrease in the viral load. Neuraminidase inhibitors are most effective when administered within 48 hours of the onset of symptoms, as they can significantly reduce the duration of illness and the risk of complications.

Pharmacokinetics

Antivirals such as oseltamivir are administered orally and are quickly absorbed from the gastrointestinal tract. The drug is converted to its active form, oseltamivir carboxylate, primarily in the liver. It has a half-life of approximately 6 to 10 hours and is predominantly eliminated via the kidneys. Patients with renal impairment may require dose adjustments to avoid toxicity.

Pregnancy

Consult healthcare provider for risks and benefits.

Breast-feeding

Consult healthcare provider for risks and benefits.

Storage

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

Indications

• Whooping cough (pertussis)
• Prevention of pertussis in infants and young children through vaccination

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

Pertussis toxin, produced by Bordetella pertussis, acts on host cells by ADP-ribosylating a G protein, which disrupts normal signal transduction pathways. This leads to increased production of cyclic AMP, inhibiting immune responses and contributing to the characteristic symptoms of the disease.

Pharmacodynamics

The clinical manifestations of pertussis are largely due to the immune response to the toxin and the bacterium itself. The disease progresses through stages: the catarrhal stage with mild symptoms, the paroxysmal stage with intense coughing fits, and the convalescent stage where symptoms gradually improve. The severity can vary, particularly in infants and young children, who are at higher risk for complications.

Pharmacokinetics

The pharmacokinetics of Bordetella pertussis are not typically described in the same manner as pharmaceutical agents. The organism does not have a traditional pharmacokinetic profile, but it primarily colonizes the ciliated epithelial cells of the upper respiratory tract. The immune clearance of the bacteria can take several weeks, depending on the host's immune response and treatment.

Adverse effects

• Cough
• Vomiting
• Fatigue
• Apnea (especially in infants)
• Weight loss
• Paroxysms of coughing
• Encephalopathy (rare)
• Pneumonia (secondary infection)

Precautions

• Use with caution in individuals with a history of seizures
• Consider potential for severe respiratory distress, especially in infants
• Monitor for complications, particularly in young children

Pregnancy

Pertussis vaccination is recommended during pregnancy to protect the newborn, especially during outbreaks.

Breast-feeding

Vaccination during breastfeeding is safe and can provide passive immunity to the infant.

Storage

Store in a cool, dry place away from direct sunlight. Follow specific storage instructions for vaccines.

Formulations

• DTaP vaccine (Diphtheria, Tetanus, and Pertussis)
• Tdap vaccine (Tetanus, Diphtheria, and Pertussis)

Indications

• Prevention of poliomyelitis
• Vaccination in children and high-risk populations

Dosage

Children: Refer to the BNF for Children for appropriate dosing schedules and recommendations for poliovirus vaccination in children.

Adults: Refer to specific guidelines for IPV and OPV administration in adults, as vaccination schedules may vary based on age and immunization history.

Mechanism of action

Poliovirus primarily infects the motor neurons of the spinal cord and brainstem, leading to cell lysis and apoptosis. The viral replication occurs in the cytoplasm of the host cells, resulting in the release of new virions. The immune response triggered by the infection can lead to paralysis due to damage to the motor neurons.

Pharmacodynamics

The pharmacodynamics of polio vaccines involve the induction of an immune response against the poliovirus. The IPV induces serum neutralizing antibodies, while the OPV induces both serum and mucosal immunity. This immune response prevents the establishment of infection and protects against the disease.

Pharmacokinetics

Poliovirus vaccines do not have a pharmacokinetic profile in the traditional sense, as they are biological products. However, the IPV is administered intramuscularly, leading to systemic absorption and subsequent immunogenicity. The OPV is administered orally, leading to replication in the gastrointestinal tract and inducing both humoral and cellular immunity.

Contra-indications

• Severe allergic reaction to polio vaccine components
• Immunocompromised state (inactivated vaccine preferred)

Adverse effects

• Injection site reactions (pain, swelling, redness)
• Fever
• Fatigue
• Gastrointestinal disturbances (nausea, vomiting)
• Rarely, vaccine-derived paralytic poliomyelitis

Interactions

• Live vaccines may be affected by immunosuppressive therapies
• Concurrent administration with other vaccines is generally safe but consult vaccination guidelines

Precautions

• History of allergic reactions
• Patients with a history of Guillain-Barré syndrome
• Caution in patients with neurological disorders

Pregnancy

Polio vaccination is recommended during pregnancy if the woman is at risk of exposure, as the benefits outweigh potential risks.

Breast-feeding

Polio vaccine can be administered to breastfeeding mothers without risk to the infant.

Storage

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

Formulations

• Inactivated poliovirus vaccine (IPV)
• Oral poliovirus vaccine (OPV)

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