Which statement about H1 antihistamines is true?

Which statement about H1 antihistamines is true?

• A. Second-generation H1 antihistamines are relatively free of adverse effects.
• B. First-generation H1 antihistamines are the first choice for allergic rhinitis due to safety.
• C. First-generation H1 antihistamines do not affect motor coordination.
• D. H1 antihistamines can effectively treat acute anaphylaxis.

Answer: (A)

Second-generation H1 antihistamines are characterized by their selective action on peripheral H1 receptors and their ability to cross the blood-brain barrier to a much lesser extent than first-generation agents. This reduced central nervous system penetration leads to fewer sedative effects and a lower incidence of other adverse effects commonly associated with first-generation antihistamines, such as drowsiness and impaired motor coordination. Due to this profile, second-generation H1 antihistamines are often preferred for the management of allergic conditions like allergic rhinitis because they offer efficacy with a more favorable safety profile.

Second-generation H1 antihistamines are characterized by their selective action on peripheral H1 receptors and their ability to cross the blood-brain barrier to a much lesser extent than first-generation agents. This reduced central nervous system penetration leads to fewer sedative effects and a lower incidence of other adverse effects commonly associated with first-generation antihistamines, such as drowsiness and impaired motor coordination. Due to this profile, second-generation H1 antihistamines are often preferred for the management of allergic conditions like allergic rhinitis because they offer efficacy with a more favorable safety profile.