Nemonapride

Overview of the antipsychotic medication Nemonapride

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

Nemonapride is an atypical antipsychotic medication primarily used in the treatment of schizophrenia and other psychotic disorders. It is known for its unique pharmacological profile and is utilized in certain countries for its therapeutic effects.

Pharmacology

Nemonapride functions as a selective dopamine receptor antagonist, with a high affinity for the D2 and D3 subtypes. This action helps in modulating the dopaminergic activity in the brain, which is often dysregulated in psychotic disorders. Unlike typical antipsychotics, nemonapride has a lower incidence of extrapyramidal symptoms, making it a preferable option for some patients.

Clinical Use

Nemonapride is primarily indicated for the management of schizophrenia. It is effective in reducing both positive symptoms, such as hallucinations and delusions, and negative symptoms, such as anhedonia and social withdrawal. The medication is administered orally and is typically prescribed in a controlled dosage to minimize potential side effects.

Side Effects

Common side effects of nemonapride include sedation, weight gain, and gastrointestinal disturbances. Due to its dopaminergic activity, there is also a risk of developing tardive dyskinesia with long-term use. Patients are advised to undergo regular monitoring to manage and mitigate these risks.

Mechanism of Action

Chemical structure of Nemonapride

Nemonapride's mechanism of action involves the blockade of dopamine receptors, particularly the D2 and D3 subtypes. This blockade reduces the overactivity of dopamine pathways that are implicated in the pathophysiology of schizophrenia. Additionally, nemonapride may have some affinity for serotonin receptors, contributing to its atypical profile.

History and Development

Nemonapride was developed in Japan and has been used in clinical practice since the late 20th century. Its development was part of a broader effort to create antipsychotic medications with fewer side effects compared to earlier drugs like haloperidol.

Related pages

• Antipsychotic
• Schizophrenia
• Dopamine receptor
• Tardive dyskinesia