Tylotong

Mechanism of action

Bisulfite functions primarily as a reducing agent in biochemical reactions. It can donate electrons, which is essential in various metabolic processes, including the degradation of cysteine and homocysteine. The compound is involved in pathways related to amino acid metabolism, specifically influencing sulfur amino acid metabolism, which is critical in maintaining cellular redox homeostasis.

Pharmacodynamics

The pharmacodynamic properties of bisulfite include its role in reducing oxidative stress by participating in redox reactions. It helps maintain the balance of thiol groups within proteins, which is vital for their structural integrity and function. Additionally, bisulfite may influence the activity of certain enzymes involved in the metabolism of amino acids.

Pharmacokinetics

Information on the pharmacokinetics of bisulfite is limited. However, it is known to be rapidly absorbed and metabolized in the body. Its primary metabolic pathways involve the degradation of sulfur-containing amino acids. Excretion typically occurs through urine, reflecting its metabolic products.

Pregnancy

Bisulfite is not recommended during pregnancy due to potential risks, consult healthcare professionals for alternatives.

Breast-feeding

Caution is advised when using bisulfite while breastfeeding, consult with healthcare professionals before use.

Storage

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

Indications

• Electrolyte replacement
• Volume expansion in hypovolemic patients
• Management of hyponatremia
• Support in intravenous fluid therapy

Dosage

Children: Refer to the BNF for Children for appropriate dosing in paediatric patients, as dosages may vary based on the formulation and clinical condition.

Adults: Refer to specific product information or clinical guidelines for dosage recommendations, as disodium is often part of combination products.

Mechanism of action

Disodium compounds often function by providing sodium ions that are essential for various physiological processes. Sodium ions play a critical role in maintaining osmotic balance, nerve impulse transmission, and muscle contraction. In the context of intravenous solutions, disodium helps to restore electrolyte balance in patients.

Pharmacodynamics

The pharmacodynamics of disodium is primarily related to its role in electrolyte balance and fluid homeostasis. Sodium ions are vital for the function of excitable tissues, including neurons and muscle cells. Changes in sodium levels can affect blood pressure, hydration status, and overall cellular function.

Pharmacokinetics

The pharmacokinetics of disodium compounds depend on their specific formulation and route of administration. When administered intravenously, disodium is rapidly distributed in the extracellular fluid, where it helps to maintain osmotic pressure. Sodium is primarily excreted by the kidneys, and its levels can be influenced by fluid intake, dietary sodium, and renal function.

Pregnancy

Use with caution. Consult a healthcare provider for specific guidance.

Breast-feeding

Use with caution. Consult a healthcare provider for specific guidance.

Storage

Store at room temperature, away from moisture and direct sunlight.

Indications

• Lead poisoning
• Mercury poisoning
• Calcium overload
• Certain diagnostic procedures involving heavy metals

Dosage

Children: Refer to the BNF for Children for appropriate dosing information tailored for paediatric patients.

Adults: Refer to the BNF for specific dosing guidelines based on the condition being treated, considering factors such as the severity of metal poisoning and renal function.

Mechanism of action

Edetate functions by forming stable complexes with divalent and trivalent metal ions, including lead and calcium, through its multiple carboxylate and amine groups. This chelation renders the metals more soluble and promotes their renal excretion, thereby reducing their toxic effects in the body.

Pharmacodynamics

The chelation of metals by edetate decreases the free metal concentration in the bloodstream, which mitigates the toxic effects associated with heavy metal accumulation. The efficacy of edetate in removing metals such as lead has been well documented, and its ability to bind calcium can influence calcium homeostasis in certain clinical scenarios.

Pharmacokinetics

Edetate is administered intravenously, with rapid distribution throughout the extracellular fluid. It is primarily excreted unchanged by the kidneys. The onset of action occurs quickly after administration, and the duration depends on the dose and the patient's renal function. The elimination half-life is approximately 1 hour but may vary based on renal clearance.

Contra-indications

• Hypersensitivity to edetate or any component of the formulation
• Severe renal impairment
• Active bleeding disorders

Adverse effects

• Hypocalcemia
• Nausea
• Vomiting
• Diarrhea
• Abdominal pain
• Headache
• Rash
• Fever

Interactions

• May enhance the effects of anticoagulants
• Concurrent use with calcium supplements may reduce effectiveness
• May interfere with the absorption of certain medications due to changes in gastrointestinal motility

Precautions

• Use with caution in patients with renal impairment
• Monitor electrolyte levels, particularly calcium, during treatment
• Assess the patient's hydration status before administration

Pregnancy

Limited data on the use of edetate in pregnancy. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Caution is advised as it is not known whether edetate is excreted in human milk. Weigh the risks and benefits before use.

Storage

Store in a cool, dry place, protected from light. Do not freeze.

Formulations

• Edetate disodium injection
• Edetate calcium disodium injection

Indications

• Bacterial infections in livestock
• Respiratory infections
• Enteritis caused by various pathogens
• Mycoplasma infections

Dosage

Children: For paediatric dosing, refer to the BNF for Children for appropriate dosing information based on age and weight.

Adults: Refer to the BNF for specific dosing guidelines based on the condition being treated, as doses may vary.

Mechanism of action

Tylosin inhibits peptide bond formation by binding to the 50S ribosomal subunit of bacteria, blocking the aminoacyl-tRNA from entering the ribosome and thus halting protein synthesis. This inhibition acts as a slow-binding, slowly reversible process, and the interaction with the ribosome is characterized by a significant degree of irreversibility, which is crucial for its antibiotic properties.

Pharmacodynamics

Tylosin exhibits bacteriostatic activity, meaning it inhibits bacterial growth rather than directly killing bacteria. Its effectiveness is particularly notable against certain strains of bacteria that are resistant to other antibiotic classes. The irreversibility of its action on the ribosome contributes to its long-lasting effects against bacterial infections.

Pharmacokinetics

After administration, tylosin is absorbed and distributed throughout the body. It is metabolized in the liver and excreted primarily in the bile, with some renal excretion. The half-life of tylosin can vary based on the route of administration and the species being treated. It is important to monitor for potential accumulation in cases of renal impairment.

Pregnancy

There is insufficient data on the use of tylosin during pregnancy. It should only be used if the potential benefits outweigh the risks.

Breast-feeding

It is not known whether tylosin is excreted in human milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Formulations

• Tylosin tartrate tablets
• Tylosin injectable solution
• Tylosin oral suspension

Mechanism of action

The inhibition of peptide bond formation by tylosin, a 16-membered ring macrolide, was studied in a model system derived from Escherichia coli. In this cell-free system, a peptide bond is formed between puromycin (acceptor substrate) and AcPhe-tRNA (donor substrate) bound at the P-site of poly(U)-programmed ribosomes. It is shown that tylosin inhibits puromycin reaction as a slow-binding, slowly reversible inhibitor. Detailed kinetic analysis reveals that tylosin (I) reacts rapidly with complex C, i.e., the AcPhe-tRNA. poly(U).70S ribosome complex, to form the encounter complex CI, which then undergoes a slow isomerization and is converted to a tight complex, CI, inactive toward puromycin. These events are described by the scheme C + I <==> (K(i)) CI <==> (k(4), k(5)) CI. The K(i), k(4), and k(5) values are equal to 3 microM, 1.5 min(-1), and 2.5 x 10(-3) min(-1), respectively. The extremely low value of k(5) implies that the inactivation of complex C by tylosin is almost irreversible. The irreversibility of the tylosin effect on peptide bond formation is significant for the interpretation of this antibiotic's therapeutic properties; it also renders the tylosin reaction a useful tool in the study of other macrolides failing to inhibit the puromycin reaction but competing with tylosin for common binding sites on the ribosome. Thus, the tylosin reaction, in conjunction with the puromycin reaction, was applied to investigate the erythromycin mode of action. It is shown that erythromycin (Er), like tylosin, interacts with complex C according to the kinetic scheme C + Er <==> (K(er)) CEr <==> (k(6), k(7)) C*Er and forms a tight complex, CEr, which remains active toward puromycin. The determination of K(er), k(6), and k(7) enables us to classify erythromycin as a slow-binding ligand of ribosomes