EUVICHOL-S

Indications

• Acute watery diarrhea caused by cholera
• Severe dehydration due to cholera
• Electrolyte imbalances resulting from cholera

Dosage

Children: Refer to guidelines for specific rehydration protocols and antibiotic choices based on local guidelines.

Adults: Refer to guidelines for specific rehydration protocols and antibiotic choices based on local guidelines.

Mechanism of action

The pathogenicity of Vibrio cholerae is largely due to the cholera toxin (CT), which is an AB toxin. The A subunit of the toxin enters intestinal epithelial cells and activates adenylate cyclase, leading to an increase in cyclic AMP (cAMP) levels. Elevated cAMP causes secretion of chloride ions into the intestinal lumen, accompanied by sodium and water, resulting in profuse watery diarrhea.

Pharmacodynamics

The primary pharmacodynamic effect in cholera treatment is the restoration of fluid and electrolyte balance through rehydration. In cases where antibiotics are used, they reduce the bacterial load and the production of cholera toxin, leading to a decrease in diarrhea and gastrointestinal symptoms. The choice of antibiotic can influence the speed of recovery and the reduction of stool output.

Pharmacokinetics

Cholera treatment focuses on fluid replacement rather than pharmacokinetics of a specific drug. Oral rehydration solutions (ORS) are designed to be absorbed efficiently in the intestines. If antibiotics are administered, pharmacokinetics will vary depending on the specific antibiotic used. Generally, the absorption of orally administered antibiotics can be affected by the state of hydration and intestinal motility in cholera patients.

Adverse effects

• Dehydration
• Electrolyte imbalance
• Hypotension
• Acute kidney injury
• Shock

Precautions

• Monitor hydration status
• Electrolyte replacement may be necessary
• Use with caution in patients with pre-existing renal issues

Pregnancy

Cholera is a severe diarrheal disease. Pregnant women are at increased risk for severe complications if infected. Vaccination may be considered based on risk of exposure.

Breast-feeding

Cholera vaccination is generally considered safe during breastfeeding, but consult health care provider for specific recommendations.

Storage

Store at room temperature, away from moisture and heat. Maintain proper sanitation and hygiene to prevent contamination.

Formulations

• Oral rehydration salts
• Cholera vaccine (inactivated)

Indications

• Cholera
• Severe dehydration due to cholera
• Preventive measures in endemic areas
• Post-exposure prophylaxis in outbreak situations

Dosage

Children: Refer to clinical guidelines for specific antibiotic treatment for cholera in children, ensuring appropriate dosing based on weight and severity of the disease.

Adults: Refer to clinical guidelines for specific antibiotic treatment for cholera, taking into account the severity of the disease and local resistance patterns.

Mechanism of action

Vibrio cholerae produces cholera toxin, an enterotoxin that binds to the GM1 ganglioside receptor on intestinal epithelial cells. Once internalized, the toxin activates adenylate cyclase, leading to increased levels of cyclic AMP (cAMP) within the cell. Elevated cAMP levels result in the secretion of electrolytes and water into the intestinal lumen, causing the characteristic watery diarrhea associated with cholera.

Pharmacodynamics

The pharmacodynamic effects of cholera toxin include increased intestinal secretion of fluid and electrolytes, leading to hypersecretion and diarrhea. It is also noted for its potential to induce a strong inflammatory response, altering gut motility and absorption.

Pharmacokinetics

Cholera toxin does not have traditional pharmacokinetics like drugs; rather, its effects are localized to the intestinal lumen. It acts rapidly upon entry into the intestinal cells, with effects seen in minutes. The duration of action tends to correlate with the persistence of the toxin and the host's immune response.

Pregnancy

Cholerae vaccines are generally not recommended during pregnancy unless the benefits outweigh the risks. Consult healthcare providers for individual assessment.

Breast-feeding

The vaccine is not contraindicated during breastfeeding. However, consult healthcare providers for specific recommendations.

Storage

Store cholerae vaccines in a refrigerator at 2-8 degrees Celsius. Do not freeze. Protect from light.

Formulations

• Cholera vaccine (inactivated)
• Cholera vaccine (live attenuated)

Indications

• COVID-19
• SARS-CoV-2 infection

Dosage

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

Adults: Refer to the BNF for specific dosing recommendations based on clinical guidelines.

Mechanism of action

Nirmatrelvir is a selective inhibitor of the SARS-CoV-2 main protease (Mpro). By binding to the active site of this enzyme, nirmatrelvir prevents the cleavage of viral polyproteins, which is essential for the maturation of the virus. This ultimately inhibits viral replication.

Pharmacodynamics

Nirmatrelvir exhibits antiviral activity by specifically targeting the main protease of SARS-CoV-2. The inhibition of Mpro disrupts the viral life cycle, reducing the viral load in the body. The potency of nirmatrelvir is enhanced by ritonavir, which prolongs its action by slowing its metabolism.

Pharmacokinetics

Nirmatrelvir is rapidly absorbed after oral administration. The bioavailability is increased when combined with ritonavir, which inhibits CYP3A4, the enzyme responsible for nirmatrelvir's metabolism. The half-life of nirmatrelvir is approximately 7 hours, allowing for twice-daily dosing. It is primarily excreted via feces and urine, with minimal renal clearance.

Interactions

• nirmatrelvir boosted with ritonavir and containing ethinylestradiol: Unknown (decreases concentration)

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

• 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

• Cholera caused by Vibrio cholerae
• Gastroenteritis caused by Vibrio parahaemolyticus
• Severe diarrhea and dehydration due to Vibrio infections
• Sepsis or other systemic infections associated with Vibrio species

Dosage

Children: Refer to the BNF for Children for appropriate dosing guidelines for paediatric

Adults: Refer to specific antibiotic guidelines for treatment of Vibrio infections, as dosing varies based on the antibiotic used and severity of the infection.

Mechanism of action

Vibrio cholerae secretes cholera toxin, which activates adenylate cyclase in intestinal epithelial cells, leading to increased levels of cyclic AMP (cAMP). Elevated cAMP levels result in the secretion of electrolytes and water into the intestinal lumen, causing diarrhea and dehydration. Other Vibrio species may have different pathogenic mechanisms, including the production of enterotoxins or adherence factors that facilitate colonization in the gut.

Pharmacodynamics

The pharmacodynamics of antibiotics used against Vibrio infections generally involve bactericidal or bacteriostatic effects, depending on the class of antibiotic used. Commonly prescribed antibiotics may inhibit bacterial cell wall synthesis, protein synthesis, or nucleic acid synthesis, leading to the death of the bacteria or inhibition of their growth. The effectiveness of treatment can be influenced by the antibiotic susceptibility profile of the specific Vibrio strain.

Pharmacokinetics

The pharmacokinetics of antibiotics used for Vibrio infections can vary widely. For instance, drugs such as doxycycline and azithromycin are often used, with doxycycline exhibiting good oral bioavailability and a half-life that allows for once or twice daily dosing. Azithromycin has a long half-life and good tissue penetration, which may enhance its effectiveness in treating bacterial infections. The distribution, metabolism, and excretion of these drugs are crucial in determining their dosing schedules and duration of therapy.

Pregnancy

No specific data available. Safety during pregnancy should be considered on a case-by-case basis, weighing potential benefits against risks.

Breast-feeding

Safety during breastfeeding is not well established; caution is advised.

Storage

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