Overview

Hypersensitivity, also known as a hypersensitivity reaction or allergic reaction, is a condition where the body's immune system reacts abnormally to a foreign substance. Such substances, that cause hypersensitivity are referred to as an allergen, could be something typically harmless to most people, like pollen or certain foods.
Types of Hypersensitivities
Hypersensitivity reactions are categorized into four types: Type 1, Type 2, Type 3, and Type 4. Each type has a distinct mechanism...

Allergic reactions related to drugs are hypersensitivity responses driven by the immune system and bear no connection to the drug's therapeutic action. While drugs in isolation do not trigger an immune response, they can interact with endogenous proteins to form antigens. These antigens stimulate lymphocytes to produce antibodies. IgE-type antibodies attach themselves to mast cells. Upon subsequent exposure to the same stimulus, the antigen-antibody interaction is initiated, unleashing...

Asthma is a chronic respiratory condition for which new therapeutic avenues, including anti-inflammatory drugs like mast cell stabilizers and anti-IgE treatments, continue to be developed.
Mast cell stabilizers, such as cromolyn (also known as sodium cromoglycate) and nedocromil (Tilade), are effective drugs in asthma management. These stabilizers hinder histamine release by skillfully obstructing the activation of mast cells and other cellular entities. Notably, they navigate this task without...

Endothelins (ETs) are potent vasoactive peptides critical in the human body's various physiological and pathological processes. One of the most promising therapeutic strategies for treating pulmonary arterial hypertension (PAH) involves counteracting the effects of these endothelins using a class of drugs known as endothelin receptor antagonists.
ETs are synthesized through a complex sequence of enzymatic steps, primarily involving an enzyme referred to as endothelin-converting enzyme...

Antihistamines are a class of drugs widely used to alleviate the symptoms of allergies, such as sneezing, itching, and nasal congestion. They work by inhibiting the actions of histamine, which is released by immune cells in response to allergenic substances or tissue injuries.
Histamine binds to specific receptor sites, known as H1 receptors, on tissue cells, triggering inflammation and swelling. Antihistamines combat these effects by competing with histamine for these receptor sites. By...