醫學四：80題 ( 包括小兒科,皮膚科,神經科,精神科等科目及其相關臨床實例與醫學倫理 )題庫下載題庫

H2 antagonists are a type of antihistamine, although in common use the term "antihistamine" is often reserved for H1 antagonists, which relieve allergic reactions. Like the H1 antagonists, some H2 antagonists function as inverse agonists rather than receptor antagonists, due to the constitutive activity of these receptors.