Antihistamine Prescribing Guide for Primary Care

Antihistamines are a cornerstone in the management of allergic disorders and certain gastrointestinal conditions. Their role in primary care is pivotal, offering symptomatic relief for a myriad of conditions ranging from the commonplace allergic rhinitis to the more complex presentations of urticaria and angioedema. The versatility of antihistamines stems from their mechanism of action, selectively targeting and blocking histamine receptors to mitigate the effects of histamine, a principal mediator in allergic reactions.

Histamine receptors, specifically the H-1 and H-2 subtypes, are widely distributed throughout the body and are integral to various physiological processes. H-1 receptor antagonists, commonly known as H-1 antihistamines, are predominantly utilized to alleviate symptoms associated with allergic reactions, such as itching, swelling, and redness. They are also used in the treatment of nausea, vomiting, and motion sickness. Conversely, H-2 receptor antagonists are primarily prescribed to reduce gastric acid secretion, thus playing a critical role in the treatment of acid reflux, peptic ulcers, and other acid-related gastrointestinal disorders.