Dexmethylphenidate hydrochloride

A medication used to treat attention deficit hyperactivity disorder (ADHD)

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

Dexmethylphenidate hydrochloride is a medication primarily used in the treatment of attention deficit hyperactivity disorder (ADHD) in children and adults. It is the d-threo-enantiomer of methylphenidate, which is a central nervous system (CNS) stimulant. Dexmethylphenidate is marketed under the brand name Focalin, among others.

Pharmacology

Dexmethylphenidate works by inhibiting the reuptake of dopamine and norepinephrine in the brain, which increases the concentration of these neurotransmitters in the synaptic cleft. This action enhances neurotransmission and is thought to contribute to its therapeutic effects in ADHD.

The drug is available in both immediate-release and extended-release formulations. The extended-release form allows for once-daily dosing, which can improve compliance in patients who have difficulty adhering to multiple daily doses.

Clinical Use

Dexmethylphenidate is indicated for the treatment of ADHD in patients aged 6 years and older. It is often used as part of a comprehensive treatment program that includes psychological, educational, and social measures.

Dosage

The dosage of dexmethylphenidate is individualized based on the patient's needs and response to the medication. It is typically started at a low dose and gradually increased. The immediate-release form is usually taken twice daily, while the extended-release form is taken once daily.

Side Effects

Common side effects of dexmethylphenidate include:

• Insomnia
• Decreased appetite
• Abdominal pain
• Headache
• Dry mouth

Serious side effects can include:

• Cardiovascular events (e.g., increased heart rate, hypertension)
• Psychiatric effects (e.g., anxiety, agitation)
• Growth suppression in children

Contraindications

Dexmethylphenidate is contraindicated in patients with:

• Known hypersensitivity to methylphenidate or any of its components
• Glaucoma
• Severe anxiety, tension, or agitation
• Concurrent use of monoamine oxidase inhibitors (MAOIs)

Mechanism of Action

Dexmethylphenidate acts as a norepinephrine-dopamine reuptake inhibitor (NDRI). By blocking the reuptake of these neurotransmitters, it increases their availability in the brain, which helps improve attention and focus in individuals with ADHD.

History

Dexmethylphenidate was approved by the Food and Drug Administration (FDA) in 2001. It was developed as a more targeted form of methylphenidate, with the aim of reducing side effects and improving efficacy by using only the active d-enantiomer.

See Also

• Methylphenidate
• Attention deficit hyperactivity disorder
• Central nervous system stimulants