Atosiban

Atosiban_SW.svg

Atosiban is a medication used as a tocolytic to delay premature birth. It is a peptide and works by inhibiting the hormones oxytocin and vasopressin. Atosiban is administered via intravenous infusion and is typically used in the management of preterm labor.

Mechanism of Action

Atosiban functions as an oxytocin receptor antagonist. By blocking the action of oxytocin, it reduces uterine contractions, thereby delaying labor. This can be crucial in providing additional time for the administration of corticosteroids to enhance fetal lung maturity or for the transfer of the pregnant woman to a facility with a neonatal intensive care unit.

Indications

Atosiban is indicated for the treatment of preterm labor between 24 and 33 weeks of gestation. It is used when there are regular uterine contractions accompanied by cervical changes.

Administration

The medication is administered in three stages: 1. An initial bolus dose. 2. A continuous high-dose infusion for three hours. 3. A lower dose infusion for up to 45 hours.

The total duration of treatment should not exceed 48 hours.

Side Effects

Common side effects of atosiban include:

• Nausea
• Headache
• Dizziness
• Injection site reactions

Serious side effects are rare but may include:

• Allergic reactions
• Cardiac issues in the fetus

Contraindications

Atosiban should not be used in cases where:

• The fetus has a lethal congenital anomaly.
• There is intrauterine infection.
• The mother has severe preeclampsia or eclampsia.
• There is significant vaginal bleeding.

Pharmacokinetics

Atosiban has a rapid onset of action, with uterine contractions typically decreasing within 10 minutes of administration. It has a half-life of approximately 1.7 hours and is metabolized primarily in the liver.

History

Atosiban was developed in the late 20th century and has been approved for use in several countries. It is marketed under various brand names, including Tractocile.

See Also

• Preterm birth
• Tocolysis
• Oxytocin
• Vasopressin
• Corticosteroids

Engineered Monoclonal Antibodies

Diagram of engineered monoclonal antibodies

Engineered monoclonal antibodies are a class of biological therapies that are designed to target specific antigens on the surface of cells. These antibodies are produced using recombinant DNA technologies and are used in the treatment of various diseases, including cancer, autoimmune disorders, and infectious diseases.

Structure and Function

Monoclonal antibodies are composed of two identical heavy chains and two identical light chains, forming a Y-shaped molecule. The tips of the "Y" contain the antigen-binding sites, which are highly specific to the target antigen. This specificity allows monoclonal antibodies to bind to their target with high affinity, blocking or modulating the function of the antigen.

Types of Engineered Monoclonal Antibodies

There are several types of engineered monoclonal antibodies, each designed for specific therapeutic purposes:

• Chimeric antibodies: These antibodies are composed of murine (mouse) variable regions and human constant regions. They are less immunogenic than fully murine antibodies.

• Humanized antibodies: These antibodies are mostly human, with only the antigen-binding sites derived from murine sources. This reduces the risk of immune reactions.

• Fully human antibodies: These are entirely human in origin, produced using transgenic mice or phage display technologies.

• Bispecific antibodies: These antibodies are engineered to bind two different antigens simultaneously, offering unique therapeutic mechanisms.

Applications in Medicine

Engineered monoclonal antibodies have revolutionized the treatment of many diseases:

• Cancer therapy: Monoclonal antibodies can target specific tumor antigens, leading to direct tumor cell killing or recruitment of immune cells to attack the tumor.

• Autoimmune diseases: By targeting specific components of the immune system, monoclonal antibodies can reduce inflammation and tissue damage in diseases such as rheumatoid arthritis and multiple sclerosis.

• Infectious diseases: Monoclonal antibodies can neutralize pathogens or their toxins, providing passive immunity or enhancing the host's immune response.

Production

The production of engineered monoclonal antibodies involves several steps:

1. Antigen identification: The target antigen is identified and characterized. 2. Hybridoma technology: B cells from immunized animals are fused with myeloma cells to create hybridomas that produce the desired antibody. 3. Recombinant DNA technology: Genes encoding the antibody are cloned and expressed in suitable host cells, such as Chinese hamster ovary cells. 4. Purification and formulation: The antibodies are purified and formulated for clinical use.

Challenges and Future Directions

While engineered monoclonal antibodies have shown great promise, there are challenges such as high production costs, potential for immune reactions, and the development of resistance. Ongoing research aims to improve antibody design, reduce immunogenicity, and enhance therapeutic efficacy.

Related Pages

• Monoclonal antibody therapy
• Biopharmaceutical
• Immunotherapy
• Hybridoma technology

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