The following is a summary of “Evidence-based use of antihistamines for treatment of allergic conditions,” published in the October 2023 issue of Allergy, Asthma & Immunology by Linton, et al.

H₁ antihistamines have been used to treat allergic diseases like allergic rhinitis and hives since the 1940s. As inverse agonists, they link to the H₁ receptor and stop the inflammation that histamine causes. The older, first-generation drugs are not recommended for patients anymore because they have a history of bad side effects that have been well-recorded. More and more evidence supports a younger line of H₁ antihistamines that can be taken by mouth or inhaled, even when combined with inhaled corticosteroids. 

Many big meta-analyses and systematic reviews have been done on the safety and effectiveness of second-generation H₁ antihistamines in adults and children with allergic rhinitis. These studies include combination nasal spray drugs like MP29-02 and MP-AzeFlu. There are differences within classes, but what matters most are the patients’ preferences, their ability to get care, and the prices. Strong evidence on the regular, not just when needed, use of H1 antihistamines for urticaria has been made public. 

This includes how to treat children and women who are pregnant or breastfeeding. If necessary, H1 antihistamines can also help people with other allergic conditions, like the secondary signs of anaphylaxis, feel better. This can include people with allergic asthma.

Source: sciencedirect.com/science/article/abs/pii/S1081120623005240