Ameropem

Indications

• Bacterial infections
• Hospital-acquired septicaemia
• Complicated urinary-tract infections including pyelonephritis
• Complicated intra-abdominal infections
• Meningitis
• Endocarditis (in combination with another antibacterial)
• Hospital-acquired pneumonia
• Ventilator-associated pneumonia

Dosage

Adults: 0.5–1 g every 8 hours, for complicated urinary-tract infections, complicated intra-abdominal infections, and bacterial meningitis, 2 g every 8 hours for 5-10 days; may be continued for up to 14 days depending on the site of infection.

Mechanism of action

The bactericidal activity of meropenem results from the inhibition of cell wall synthesis. It readily penetrates the cell wall of most Gram-positive and Gram-negative bacteria to reach penicillin-binding protein (PBP) targets. Its strongest affinities are toward PBPs 2, 3, and 4 of Escherichia coli and Pseudomonas aeruginosa, and PBPs 1, 2, and 4 of Staphylococcus aureus.

Pharmacodynamics

Meropenem is a broad-spectrum carbapenem antibiotic that is active against both Gram-positive and Gram-negative bacteria. It penetrates bacterial cells and interferes with the synthesis of vital cell wall components, leading to cell death. The bactericidal concentrations are generally 1-2 times the bacteriostatic concentrations.

Pharmacokinetics

Meropenem is administered intravenously and has a volume of distribution of approximately 0.2-0.3 L/kg, indicating rapid distribution into body fluids and tissues. It is primarily eliminated via the kidneys, with a half-life of around 1 hour. Dose adjustments are recommended in patients with renal impairment, particularly those with creatinine clearance less than 90 mL/minute.

Contra-indications

• History of hypersensitivity to meropenem or any component of the formulation
• Severe allergic reactions to other beta-lactam antibiotics

Adverse effects

• Abdominal pain
• Diarrhoea
• Nausea
• Vomiting
• Headache
• Skin reactions
• Thrombocytosis
• Bacteraemia
• Seizures
• Agitation
• Increased risk of infection
• Antibiotic-associated colitis
• Eosinophilia
• Hemolytic anemia
• Leukopenia
• Neutropenia
• Paraesthesia
• Severe cutaneous adverse reactions (SCARs)
• Thrombophlebitis

Interactions

• Other nephrotoxic agents may enhance the risk of renal toxicity
• Probenecid may reduce renal clearance and increase serum levels of meropenem

Precautions

• Caution in patients with renal impairment; dose adjustments may be necessary
• Monitor liver function due to risk of hepatotoxicity
• Caution in patients with a history of seizures or central nervous system disorders
• Positive Coombs' test reported

Pregnancy

Meropenem should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Meropenem is excreted in breast milk; caution should be exercised when administering to nursing mothers.

Storage

Store in a cool, dry place. Protect from light. After reconstitution, use promptly or store as recommended in product guidelines.

Formulations

• Powder for solution for injection 500 mg
• Powder for solution for injection 1 g
• Powder for solution for infusion

Mechanism of action

Carbonate ions participate in buffering reactions that help maintain pH homeostasis in biological systems. They can react with acids to form bicarbonate and carbon dioxide, thus neutralizing excess acidity in the body. This mechanism is crucial in processes such as respiration and metabolism.

Pharmacodynamics

As a buffer, carbonate helps to stabilize pH levels in different biological environments, preventing excessive acidity or alkalinity that could impair cellular functions. It is involved in the transport of carbon dioxide in the blood and plays a role in maintaining the acid-base equilibrium necessary for physiological processes.

Pharmacokinetics

Carbonate ions are readily absorbed in the gastrointestinal tract when ingested and can be found in various body fluids. They are involved in the bicarbonate buffering system, where they are converted to bicarbonate (HCO3-) and carbon dioxide (CO2) through reactions with acids. The kidneys regulate the levels of bicarbonate and carbonate in the body, excreting or reabsorbing them as needed to maintain homeostasis.

Pregnancy

There is no specific information available regarding the use of carbonate compounds during pregnancy. Consult a healthcare provider for advice.

Breast-feeding

There is no specific information available regarding the use of carbonate compounds while breastfeeding. Consult a healthcare provider for advice.

Storage

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

Indications

• Pain relief
• Fever reduction
• Treatment of respiratory conditions
• Management of inflammation
• Cough relief
• Antibiotic therapy

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines tailored to paediatric populations, as dosages will depend on the formulation and active ingredients used in the mixture.

Adults: Refer to specific drug combinations for appropriate dosing recommendations, as dosages will vary widely based on the active ingredients included.

Mechanism of action

The mechanism of action of a mixture depends on the specific active ingredients included. For instance, if the mixture consists of an analgesic and an anti-inflammatory, the analgesic may work by inhibiting cyclooxygenase enzymes, thus reducing prostaglandin synthesis, while the anti-inflammatory may reduce inflammation through modulation of immune cell activity. The synergistic effects can enhance overall therapeutic outcomes.

Pharmacodynamics

Pharmacodynamics of mixtures varies based on the components involved. Each ingredient may exert its pharmacological effects through different pathways, leading to a combined effect that is often greater than the sum of individual drugs. This can involve interactions at receptor sites, modulation of enzyme activity, or alteration of metabolic pathways, improving clinical outcomes for patients.

Pharmacokinetics

Pharmacokinetics of drug mixtures is influenced by the individual pharmacokinetic profiles of each constituent. This includes absorption rates, distribution volumes, metabolism pathways, and elimination half-lives. The presence of multiple active ingredients can lead to altered absorption due to interactions, changes in protein binding, or competition for metabolic enzymes. Understanding these dynamics is crucial for optimizing dosing regimens and minimizing potential adverse effects.

Pregnancy

The safety of this mixture during pregnancy has not been established. Use only if the potential benefits outweigh the risks.

Breast-feeding

Caution is advised when using this mixture while breastfeeding. Consult a healthcare professional for guidance.

Storage

Store in a cool, dry place, away from direct sunlight and moisture. Ensure that the container is tightly closed.

Indications

• Surgical procedures
• Injection of medications
• Preparation of sterile pharmaceutical products
• Management of open wounds
• Use in controlled environments such as hospitals and laboratories

Dosage

Children: Refer to specific drug monographs for dosage information as sterile itself is not a pharmacological agent.

Adults: Refer to specific drug monographs for dosage information as sterile itself is not a pharmacological agent.

Mechanism of action

Sterility itself does not have a mechanism of action as it is a state of cleanliness and does not interact with biological systems. However, the methods used to achieve sterility, such as heat or chemical agents, act by denaturing proteins, disrupting cellular structures, or damaging nucleic acids in microorganisms, leading to their inactivation or destruction.

Pharmacodynamics

The pharmacodynamics of sterile techniques primarily involves the prevention of microbial infection and contamination when administering medications. By ensuring that products are sterile, the risk of adverse effects related to infections is minimized. The effectiveness of sterilization methods can be influenced by factors such as temperature, duration of exposure, and the type of microorganisms present.

Pharmacokinetics

As sterility does not pertain to a specific drug, pharmacokinetics is not applicable. However, the pharmacokinetics of a drug will depend on its formulation, route of administration, and the presence of preservatives or stabilizers that may be used alongside sterile preparations.

Pregnancy

Sterile preparations are generally considered safe during pregnancy as they are used to provide hydration, nutrition, or medications in a controlled manner, but specific formulations should be assessed individually.

Breast-feeding

Sterile solutions used for hydration or nutritional support are typically safe during breastfeeding, but any specific additives or medications within the solutions should be evaluated for safety.

Storage

Sterile solutions should be stored in a cool, dry place, protected from light, and should be used before the expiration date. Once opened, they may have specific storage requirements based on the formulation.

Formulations

• Sterile saline solution
• Sterile water for injection
• Sterile dextrose solution
• Sterile electrolyte solutions

Mechanism of action

The bactericidal activity of meropenem results from the inhibition of cell wall synthesis. Meropenem readily penetrates the cell wall of most Gram-positive and Gram-negative bacteria to reach penicillin-binding- protein (PBP) targets. Its strongest affinities are toward PBPs 2, 3 and 4 of <i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i>; and PBPs 1, 2 and 4 of <i>Staphylococcus aureus</i>. The bactericidal activity of meropenem results from the inhibition of cell wall synthesis. Meropenem readily penetrates the cell wall of most Gram-positive and Gram-negative bacteria to reach penicillin-binding-protein (PBP) targets. Its strongest affinities are toward PBPs 2, 3 and 4 of Escherichia coli and Pseudomonas aeruginosa; and PBPs 1, 2, and 4 of Staphylococcus aureus. Bactericidal concentrations (defined as a 3 log10 reduction in cell counts within 12 to 24 hours) are typically 1-2 times the bacteriostatic concentrations of meropenem, with the exception of Listeria monocytogenes, against which lethal activity is not observed.

Pharmacodynamics

Meropenem is a broad-spectrum carbapenem antibiotic. It is active against Gram-positive and Gram-negative bacteria. Meropenem exerts its action by penetrating bacterial cells readily and interfering with the synthesis of vital cell wall components, which leads to cell death.