Final answer:
The question discusses the effectiveness of antihistamines in treating symptoms of allergic reactions like urticaria and pruritus, but not bronchoconstriction or hypotension. Other mentioned remedies include those aiding cough production or suppression, and treatments for allergic rhinitis that alleviate associated symptoms.
Step-by-step explanation:
The subject of this question pertains to medications used to treat various allergic reactions and their symptoms, such as urticaria (hives) and pruritus (itching). Specifically, antihistamines are mentioned as effective remedies for preventing the action of histamines—substances released by mast cells that can stimulate itching and swelling. Although antihistamines can alleviate certain symptoms, they are not effective in addressing bronchoconstriction (narrowing of the airways) or hypotension (low blood pressure), which can also be manifestations of allergic reactions. Additionally, other substances are highlighted, such as those claimed to facilitate coughing by increasing the production of mucus and phlegm, and those that suppress coughing altogether. For allergic rhinitis, medications that may induce mild sedation and alleviate symptoms like runny nose and watery eyes are also addressed.