Antiviral agents against respiratory viruses

Upper respiratory tract disorders, including viral infections and allergic rhinitis, cause significant discomfort and disrupt daily life. Managing these conditions involves a variety of drugs, such as antihistamines, intranasal steroids, decongestants, antitussives, expectorants, and mucolytics. Specific examples of drugs in each category are provided.
Antihistamines (e.g., Benadryl) block histamines from binding. Histamines are chemicals released during an allergic reaction in the body. As a...

Lower respiratory tract disorders present challenges that often require skilled and nuanced approaches for effective management. Common ailments, such as asthma and chronic obstructive pulmonary disease (COPD), have prompted the development of intricate treatment strategies involving bronchodilators and anti-inflammatory drugs, each tailored to ease breathing and revitalize the lungs.
Bronchodilators, the first step of respiration enhancement, come in various forms, each with its own mechanism...

Respiratory symptoms, such as congestion and cough, commonly accompany respiratory tract conditions. Various medications, such as antitussives, expectorants, and mucolytics, play crucial roles in providing relief.
Antitussives include codeine, dextromethorphan (Robitussin), and benzonatate (Tessalon). Codeine and dextromethorphan exert their effects centrally by suppressing the cough reflex center in the medulla.  Benzonatate operates peripherally within the respiratory tract by...

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...

Decongestants are a class of medications used primarily to alleviate nasal congestion, a common symptom resulting from allergies, colds, sinusitis, and other upper respiratory tract infections. These drugs work by activating α-adrenergic receptors, constricting small blood vessels in the nasal membranes. This action results in the opening of clogged nasal passages, thereby facilitating sinus drainage and relieving congestion.
Most decongestants are readily available over-the-counter in...

Subviral agents are infectious entities that resemble viruses but lack one or more viral components, such as a capsid or essential replication machinery. These agents include viroids, prions, and satellites, each possessing distinct structural and functional characteristics that influence their mode of infection and replication.Viroids are the simplest subviral agents, consisting of circular, single-stranded RNA molecules without a protein coat. They exclusively infect plants, relying entirely...